Search

Background: Multifetal gestation could be associated with higher long‐term maternal mortality because it increases the risk of pregnancy complications such as preeclampsia and preterm birth, which are in turn linked to postpartum cardiovascular risk. Objectives: We examined whether spontaneously conceived multifetal versus singleton gestation was associated with long‐term maternal mortality in a racially diverse U.S. cohort. Methods: We ascertained vital status as of 2016 via linkage to the National Death Index and Social Security Death Master File of 44,174 mothers from the Collaborative Perinatal Project (CPP; 1959–1966). Cox proportional hazards models with maternal age as the time scale assessed associations between history of spontaneous multifetal gestation (in the last CPP observed pregnancy or prior pregnancy) and all‐cause and cardiovascular mortality, adjusted for demographics, smoking status, and preexisting medical conditions. We calculated hazard ratios (HR) for all‐cause and cause‐specific mortality over the study period and until age 50, 60, and 70 years (premature mortality). Results: Of eligible participants, 1672 (3.8%) had a history of multifetal gestation. Participants with versus without a history of multifetal gestation were older, more likely to have a preexisting condition, and more likely to smoke. By 2016, 51% of participants with and 38% of participants without a history of multifetal gestation had died (unadjusted all‐cause HR 1.14, 95% confidence interval [CI] 1.07, 1.23). After adjustment for smoking and preexisting conditions, a history of multifetal gestation was not associated with all‐cause (adjusted HR 1.00, 95% CI 0.93, 1.08) or cardiovascular mortality (adjusted HR 0.99, 95% CI 0.87, 1.11) over the study period. However, history of multifetal gestation was associated with an 11% lower risk of premature all‐cause mortality (adjusted HR 0.89, 95% CI 0.82, 0.96). Conclusions: In a cohort with over 50 years of follow‐up, history of multifetal gestation was not associated with all‐cause mortality, but may be associated with a lower risk of premature mortality. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fibroids (hormonally responsive benign tumors) often undergo volume changes in pregnancy. Because per- and polyfluoroalkyl substances (PFAS) disrupt hormonal signaling, they might affect fibroid growth. We assessed associations between PFAS and fibroid changes in pregnancy. METHODS: We analyzed seven PFAS, including perfluorohexanesulfonic acid (PFHxS), perfluorooctanesulfonic acid (PFOS), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA), in plasma collected at 10–13 wk gestation from 2,621 women in the NICHD Fetal Growth Studies – Singletons cohort (2009–2013). Sonographers recorded fibroid number and volume of the three largest fibroids during up to six timed ultrasounds. Generalized linear models assessed associations of baseline log to the base 2 transformed log2-transformed PFAS and fibroid number, volume, and presence, and weighted quantile sum regression evaluated the PFAS mixture. Generalized linear mixed models with random intercepts assessed associations of PFAS and longitudinal fibroid number and total volume. Volume analyses were stratified by total volume at first visualization [equivalent to a fibroid less than 1 centimeter <1cm (small), 1 to less than 3 centimeters 1 to < 3cm (medium), or greater than or equal to 3 centimeters ≥ 3cm (large) in diameter]. RESULTS: Fibroid prevalence was 9.4% (푛 = 245 women). PFAS were not associated with changes in fibroid number, but were associated with volume trajectory, depending on baseline volume. Among women with small volume, PFAS were associated with fibroid growth: Each doubling in PFHxS and PFOS concentrations was associated with 3.6% [95% confidence interval (CI): 0.2, 7.0 and 5.2% (95% CI: -0.4, 11.1)] greater weekly fibroid growth, respectively. Among women with medium volume, PFAS were associated with shrinking: Doublings in PFOS, PFDA, and PFUnDA concentrations were associated with 1.9% (95% CI: 0.4, 3.3), 1.2% (95% CI: 0.1, 2.4), and 1.6% (95% CI: 0.4, 2.8) greater weekly fibroid volume reduction, respectively. DISCUSSION: Certain PFAS were associated with fibroid growth among women with small fibroids and decreases among women with medium fibroids. PFAS were not associated with fibroid prevalence or number; therefore, PFAS may influence prevalent fibroids rather than initiating fibroid development. [ABSTRACT FROM AUTHOR]

To investigate the relationship of fibroids in pregnancy, preterm birth, and neonatal anthropometry. Pregnant women (n = 2578) in the National Institute of Child Health and Human Development Fetal Growth Studies–Singletons cohort had up to six ultrasounds across pregnancy. Sonographers recorded fibroid number and volume of the three largest fibroids. Trained personnel measured neonatal anthropometry. Linear and logistic regression compared neonatal anthropometry and pregnancy outcomes among pregnancies with versus without fibroids. Causal mediation analysis evaluated preterm birth as a mediator. Average birthweight did not differ by fibroid status. However, compared with pregnancies without fibroids, neonates from pregnancies with single fibroids had 0.3- (95% confidence interval [CI], 0.0, 0.5) cm larger head circumferences; those with multiple fibroids had 0.3- (95% CI, 0.0, 0.6) cm larger arm circumferences; and those with small fibroid volume had 0.7- (95% CI, 0.3, 1.2) cm larger head, 0.4- (95% CI, 0.0, 0.8) cm larger arm, and 0.7- (95% CI, 0.1, 1.3) cm larger thigh circumferences. Presence versus absence of fibroids was associated with 1.73–2.65 times higher odds of preterm birth. Differences in preterm birth did not explain fibroid-anthropometry results. We found no evidence that fibroids negatively impacted fetal growth; instead, fibroids were associated with increased head, arm, and thigh circumferences. ClinicalTrials.gov, NCT00912132. • Birthweight did not differ by fibroid status. • Based on neonatal measurements, fibroids did not appear to impede fetal growth. • Multiple and/or large fibroids were associated with higher odds of preterm birth. • Differences in preterm birth did not explain the fibroid-anthropometry results. [ABSTRACT FROM AUTHOR]

Understanding the association between mixtures of environmental toxicants and time‐to‐pregnancy (TTP) is an important scientific question as sufficient evidence has emerged about the impact of individual toxicants on reproductive health and that individuals are exposed to a whole host of toxicants rather than an individual toxicant. Assessing mixtures of chemical effects on TTP poses significant statistical challenges, namely (i) TTP being a discrete survival outcome, typically subject to left truncation and right censoring, (ii) chemical exposures being strongly correlated, (iii) appropriate transformation to account for some lipid‐binding chemicals, (iv) non‐linear effects of some chemicals, and (v) high percentage of concentration below the limit of detection (LOD) for some chemicals. We propose a discrete frailty modeling framework (named Discnet) that allows selection of correlated covariates while appropriately addressing the methodological issues mentioned above. Discnet is shown to have better and stable false negative and false positive rates compared to alternative methods in various simulation settings. We did a detailed analysis of the pre‐conception endocrine disrupting chemicals and TTP from the LIFE study and found that older females, female exposure to cotinine (smoking), DDT conferred a delay in getting pregnant, which was consistent across various approaches to account for LOD as well as non‐linear associations. [ABSTRACT FROM AUTHOR]

Understanding implications of passive smoke exposure during pregnancy is an important public health issue under the Developmental Origins of Health and Disease paradigm. In a prospective cohort of low-risk non-smoking pregnant women (NICHD Fetal Growth Studies—Singletons, 2009–2013, N = 2055), the association between first trimester passive smoke exposure and neonatal size was assessed by race/ethnicity. Plasma biomarker concentrations (cotinine, nicotine) assessed passive smoke exposure. Neonatal anthropometric measures included weight, 8 non-skeletal, and 2 skeletal measures. Linear regression evaluated associations between continuous biomarker concentrations and neonatal anthropometric measures by race/ethnicity. Cotinine concentrations were low and the percent above limit of quantification varied by maternal race/ethnicity (10% Whites; 14% Asians; 15% Hispanics; 49% Blacks). The association between cotinine concentration and infant weight differed by race/ethnicity (Pinteraction = 0.034); compared to women of the same race/ethnicity, per 1 log-unit increase in cotinine, weight increased 48g (95%CI -44, 139) in White and 51g (95%CI -81, 183) in Hispanic women, but decreased -90g (95%CI -490, 309) in Asian and -93g (95%CI -151, -35) in Black women. Consistent racial/ethnic differences and patterns were found for associations between biomarker concentrations and multiple non-skeletal measures for White and Black women (Pinteraction<0.1). Among Black women, an inverse association between cotinine concentration and head circumference was observed (−0.20g; 95%CI −0.38, −0.02). Associations between plasma cotinine concentration and neonatal size differed by maternal race/ethnicity, with increasing concentrations associated with decreasing infant size among Black women, who had the greatest biomarker concentrations. Public health campaigns should advocate for reducing pregnancy exposure, particularly for vulnerable populations. [ABSTRACT FROM AUTHOR]

Background: The American Academy of Pediatrics recommends that if parents choose to introduce juice, they wait until ≥12 months, citing concerns of obesity and dental caries.Objectives: We sought to identify correlates of early juice introduction (<6 months) and determine whether early introduction establishes a pattern of sugary beverage intake in childhood.Methods: Upstate KIDS is a prospective birth cohort study with follow-up through 7 years (n = 4989). The age of juice introduction was assessed from responses on periodic questionnaires from 4-18 months and categorized as <6,  6 to <12, and ≥12 months. Sociodemographic information was reported using vital records or maternal questionnaires. At 24, 30, and 36 months and 7 years, mothers reported their child's regular juice, soda, water, and milk intakes. The analysis was restricted to singletons and 1 randomly selected twin from each pair with information on juice introduction (n = 4067). We assessed associations of sociodemographic correlates with juice introduction using Cox proportional hazard models. The relations of juice introduction with beverage intake were evaluated using Poisson or logistic regression for adjusted risk ratios (aRR) or ORs, adjusting for sociodemographic covariates and total beverage intake.Results: Of the mothers, 25% and 74% introduced juice prior to 6 and 12 months, respectively. Younger maternal age; black or Hispanic race/ethnicity; lower educational attainment; Special Supplemental Nutrition Program for Women, Infants, and Children participation (yes); smoking during pregnancy; a higher pre-pregnancy BMI; a lower household income; and living in a townhouse/condominium or mobile home were associated with earlier juice introduction. Earlier juice introduction was related to a higher childhood juice intake, any soda intake, and lower water intake, holding total beverage intake constant [aRR, 1.5 (95% CI: 1.3-1.7; P-trend < 0.0001); adjusted OR 1.6 (95% CI: 1.0-2.4; P-trend = 0.01); aRR 0.9 (95% CI: 0.8-0.9; P-trend < 0.0001), respectively].Conclusions: Markers of lower socioeconomic status are strongly associated with earlier juice introduction, which, in turn, relates to sugary beverage intake in childhood, potentially replacing water. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To identify homogenous depressive symptom trajectories over the postpartum period and the demographic and perinatal factors linked to different trajectories. METHODS: Mothers (N = 4866) were recruited for Upstate KIDS, a population-based birth cohort study, and provided assessments of depressive symptoms at 4, 12, 24, and 36 months postpartum. Maternal demographic and perinatal conditions were obtained from vital records and/or maternal report. RESULTS: Four depression trajectories were identified: low-stable (74.7%), characterized by low symptoms at all waves; low-increasing (8.2%), characterized by initially low but increasing symptoms; medium-decreasing (12.6%), characterized by initially moderate but remitting symptoms; and high-persistent (4.5%), characterized by high symptoms at all waves. Compared with the high-persistent group, older mothers (maximum odds ratio [OR] of the 3 comparisons: 1.10; 95% confidence interval [CI]: 1.05 to 1.15) or those with college education (maximum OR: 2.52; 95% CI: 1.36 to 4.68) were more likely to be in all other symptom groups, and mothers who had a history of mood disorder (minimum OR: 0.07; 95% CI: 0.04 to 0.10) or gestational diabetes mellitus diagnosis (minimum OR: 0.23; 95% CI: 0.08 to 0.68) were less likely to be in other symptom groups. Infertility treatment, multiple births, prepregnancy BMI, gestational hypertension, and infant sex were not differentially associated with depressive symptom trajectories. CONCLUSIONS: One-quarter of mothers in a population-based birth cohort had elevated depressive symptoms in 3 years postpartum. Screening for maternal depression beyond the postpartum period may be warranted, particularly after mood and diabetic disorders. [ABSTRACT FROM AUTHOR]

Background: Identifying the impact of environmental mixtures on human health is an important topic. However, such studies face challenges when exposure measurements lie below limit of detection (LOD). While various approaches for accommodating a single exposure subject to LOD have been used, their impact on mixture analysis has not been thoroughly investigated. Our study aims to understand the impact of five popular LOD accommodation approaches on mixture analysis results with multiple exposures subject to LOD, including omitting subjects with any exposures below LOD (complete case analysis); single imputations by LOD/ 2 , and by estimates from a censored accelerated failure time (AFT) model; and multiple imputation (MI) with or without truncation based on LOD. Methods: In extensive simulation studies with high-dimensional and highly correlated exposures and a continuous health outcome, we examined the performance of each LOD approach on three mixture analysis methods: elastic net regression, weighted quantile sum regression (WQS) and Bayesian kernel machine regression (BKMR). We further analyzed data from the National Health and Nutrition Examination Survey (NHANES) on how persistent organic pollutants (POPs) influenced leukocyte telomere length (LTL). Results: Complete case analysis was inefficient and could result in severe bias for some mixture methods. Imputation by LOD/ 2 showed unstable performance across mixture methods. Conventional MI was associated with consistent mild biases, which can be reduced by using a truncated distribution for imputation. Estimating censored values by AFT models had a minimal impact on the results. In the NHANES analysis, imputation by LOD/ 2 , truncated MI and censored AFT models performed similarly, with a positive overall effect of POPs on LTL while PCB126, PCB169 and furan 2,3,4,7,8-pncdf being the most important exposures. Conclusions: Our study favored using truncated MI and censored AFT models to accommodate values below LOD for the stability of downstream mixture analysis. [ABSTRACT FROM AUTHOR]

Background: Evidence shows cytokine dysregulation in children with developmental disabilities. The association between immune activity during the perinatal period and child development is less clear.Methods: We examined the relationship between newborn concentrations of immune markers and child development. Within Upstate KIDS, a population-based birth cohort (2008-2010, upstate New York), we assayed immune markers, which are postulated to have neuro-modulatory effects, in newborn dried blood spots (NDBS, n = 3038). Mothers completed the Ages & Stages Questionnaire© (ASQ) for their children repeatedly through age 36 months. At 30 and 36 months, mothers also reported whether their children received any developmental services. We used generalised linear mixed models adjusted for maternal and child characteristics to test associations.Results: Sixteen immune markers were associated with failing ASQ in unadjusted models. After full adjustment (for gestational age, mode of delivery, parity, pregnancy smoking, etc.), we observed that higher levels of 4 markers, including platelet-derived growth factor-AA (PDGF-AA, OR 0.77, 95% CI 0.67, 0.89), plasminogen activator inhibitor-1 (OR 0.80, 95% CI 0.68, 0.94), stromal cell derived factor-1 (OR 0.85, 95% CI 0.73, 0.98), and macrophage inflammatory protein-1beta (OR 0.87, 95% CI 0.77, 0.98) were associated with lower odds of ASQ failure. The associations did not exist if correction for multiple comparisons was performed, except for PDGF-AA. Analyses with developmental service use revealed similar null findings.Conclusions: Immune marker concentrations in NDBS may not be associated with developmental delay in the general population. Newborn concentrations of growth factor PDGF-AA may be protective of developmental delay in childhood. [ABSTRACT FROM AUTHOR]

Study Question: Is maternal polycystic ovarian syndrome (PCOS) associated with developmental delays in offspring?Summary Answer: Offspring of mothers with PCOS were at higher risk of failure on the Ages and Stages Questionnaire (ASQ).What Is Known Already: There is growing evidence that offspring of mothers with PCOS may be at higher risk for developmental disorders due to potential exposure to hyperandrogenism and insulin resistance. Few studies exist regarding maternal PCOS and early childhood development in the USA.Study Design, Size, Duration: The Upstate KIDS Study is a population-based prospective cohort study of infants born between 2008 and 2010 in New York State (excluding New York City), originally designed to study-and finding no impact of-infertility treatment exposure on child development. Children were followed up to 36 months of age. In all, 4453 mothers completed one or more developmental screening instruments for 5388 children (35.5% twins) up to 36 months of age.Participants/materials, Setting, Methods: In our study, 458 mothers (10.3%) reported a healthcare provider's diagnosis of PCOS, as well as the related treatment received, on the baseline study questionnaire. Parents completed the ASQ on their child's development at 4, 8, 12, 18, 24, 30 and 36 months of age to assess fine motor, gross motor, communication, personal-social functioning and problem-solving cognitive domains. We used generalized linear mixed models to estimate odds ratios (OR) between PCOS diagnosis and failures in the ASQ adjusted for maternal age, race, BMI, education, marital status, smoking, alcohol consumption, diabetes, insurance and plurality.Main Results and the Role Of Chance: Diagnosis of PCOS was associated with increased risk of the offspring failing the fine motor domain (adjusted odds ratio (aOR) = 1.77; 95% CI: 1.09, 2.89), largely driven by higher risk in female singletons (aOR = 2.23; 1.16, 4.29). Twins of mothers with PCOS had higher risk of failing the communication (aOR = 1.94; 1.19, 3.18) and personal-social functioning (aOR = 1.76; 1.12, 2.77) domains compared to twins born to mothers without PCOS. Compared to offspring of women without PCOS, offspring of women who reported receiving no treatment for their PCOS had a stronger association with failing the ASQ (aOR = 1.68; 0.95, 2.75) than the association among offspring of women who reported PCOS treatment (aOR = 1.16; 0.79, 1.73).Limitations, Reasons For Caution: Further study is needed to confirm the role of maternal PCOS in early offspring development with provider-validated diagnosis of PCOS.Wider Implications Of the Findings: If confirmed, these findings suggest that offspring of women with PCOS may be at increased risk for developmental delay.Study Funding/competing Interest(s): Supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD; contracts HHSN275201200005C, #HHSN267200700019C). Authors have no competing interests to declare.Trial Registration Number: Not applicable. [ABSTRACT FROM AUTHOR]

Background Little is known about the predictors of sexual intercourse frequency (SIF) among couples trying to conceive despite the well-established link between SIF and fecundity. Aim To evaluate men's and women's demographic, occupational, and lifestyle predictors of SIF among couples. Methods 469 Couples without a history of infertility participating in the Longitudinal Investigation of Fertility and the Environment Study (2005–2009) were followed up for ≤1 year while trying to conceive. At enrollment, both partners were interviewed about demographic, occupational, lifestyle, and psychological characteristics using standardized questionnaires. Multivariable generalized linear mixed models with Poisson distribution were used to estimate the adjusted percent difference in SIF across exposure categories. Outcomes SIF was recorded in daily journals and summarized as average SIF/mo. Results The median (interquartile range) SIF during follow-up was 6 (4–9) acts/mo. For every year increase in age for women and men, SIF decreased by –0.8% (95% CI –2.5 to 1.0%) and –1.7% (95% CI –3.1 to –0.3%). Women with high school education or less and those of non-white race had 34.4% and 16.0% higher SIF, respectively. A similar trend was seen for men's education and race. Only couples where both partners (but not just 1 partner) worked rotating shifts had –39.1% (95% CI –61.0 to –5.0%) lower SIF compared to couples where neither partner worked rotating shifts. Men's (but not women's) exercise was associated with 13.2% (95% CI 1.7–26.0%) higher SIF. Diagnosis of a mood or anxiety disorder in men (but not women) was associated with a 26.0% (95% CI –42.7 to –4.4%) lower SIF. Household income, smoking status, body mass index, night work, alcohol intake, and psychosocial stress were not associated with SIF. Clinical Translation Even among couples trying to conceive, there was substantial variation in SIF. Both partners' age, education, race, and rotating shift work as well as men's exercise and mental health play an important role in determining SIF. Conclusions As this was a secondary analysis of an existing study, we lacked information on many pertinent psychological and relationship quality variables and the hormonal status of participants, which could have affected SIF. The unique population-based couple design, however, captured both partners' demographics, occupational characteristics, and lifestyle behaviors in advance of their daily, prospective reporting of SIF, which was a major strength. Important predictors of SIF among couples attempting to conceive include men's exercise and mental health and both partners' age, education, race, and rotating shift work. Gaskins AJ, Sundaram R, Buck Louis GM, et al. Predictors of Sexual Intercourse Frequency Among Couples Trying to Conceive. J Sex Med 2018;15:519–528. [ABSTRACT FROM AUTHOR]

Study Question: Are biomarkers of preconception stress associated with pregnancy loss?Summary Answer: Preconception stress, as measured by basal salivary cortisol and alpha-amylase concentrations, is not associated with pregnancy loss.What Is Known Already: Many studies, most of which have been retrospective, have identified an association between stressful life events and perceived stress and miscarriage.Study Design, Size, Duration: A prospective pregnancy study with preconception enrollment was conducted between 2005 and 2009. Among the 344 women who became pregnant during the Longitudinal Investigation of Fertility and the Environment (LIFE) study, 337 (98%) had salivary biomarker data for analysis.Participants/materials, Setting, Methods: Couples planning pregnancy were followed for up to 12 months as they tried to become pregnant and through pregnancy if it occurred. Participating women collected a basal saliva sample on the morning following enrollment and a second on the morning following their next menses to measure cortisol and alpha-amylase, biomarkers of stress. Women used home pregnancy tests on the day of expected menses. A pregnancy loss was defined as a negative pregnancy test following a positive pregnancy test, the onset of menses, or for pregnancies that survived to clinical recognition, recognition of the loss by a healthcare provider.Main Results and the Role Of Chance: Among the 337 couples, the median age of female and male partners was 29 and 31 years, respectively. Most of the women were non-Hispanic white (83%) and highly educated. There were 97 pregnancy losses reported among the 337 pregnancies. The median gestational age at loss was 6 weeks 5 days with only two losses occurring in the second trimester. Using Cox proportional hazards models, we found no clear pattern of association between two preconceptional biomarkers of stress (salivary cortisol and alpha-amylase concentrations) modeled both continuously or in tertiles and incident pregnancy loss after adjustment for confounders.Limitations Reasons For Caution: Our prior work suggests that women enrolled in the LIFE Study had lower stress levels than women in the general population. Owing to concerns regarding participant burden, we were unable to collect serial saliva measurements, which would have allowed us to examine the association between stress in early pregnancy and pregnancy loss. Further, with regard to the measurement of perceived stress, the Cohen's Perceived Stress Scale was only administered at baseline. While every attempt was made to ensure diversity in the cohort, non-Hispanic white women were over-represented, therefore it is possible that the results might not be generalizable to all women.Wider Implications Of the Findings: In one of the largest studies in the USA to prospectively capture data on the incidence of early pregnancy loss, we found no clear association between two biomarkers of preconception stress (measured in saliva) and pregnancy loss.Study Funding/competing Interest(s): This study was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (contracts #N01-HD-3-3355, N01-HD-3-3356, N01-HD-3358). There are no conflicts of interest to declare.Trial Registration Number: Not applicable. [ABSTRACT FROM AUTHOR]

In biomedical studies, one is often interested in repeat events with longitudinal observations occurring only intermittently, resulting in panel count data. The first stage of labor, measured through unit-increments of cervical dilation in pregnant women, provides such an example. Obstetricians are interested in assessing the gap time distribution of per-unit increments of cervical dilation for better management of labor process. Typically, only intermittent medical examinations for cervical dilation occur after (already dilated) women get admitted to hospital. The observation frequency is very likely correlated to how fast/slow she dilates. Thus, one could view such data as panel count data with informative observation times and unknown start time. Here, we propose semiparametric proportional rate models for the event process and the observation process, with a multiplicative subject-specific frailty variable capturing the correlation between the two processes. Inference procedures for the gap times between consecutive events are proposed when the start times are known as well when unknown, using likelihood-based approach and estimating equations. The methodology is assessed through simulation study and through large sample property. A detailed analysis using the proposed methods is applied to data from two studies: the Collaborative Perinatal Project and the Consortium on Safe Labor. Supplementary materials for this article are available online. [ABSTRACT FROM AUTHOR]

Objective: To assess the morbidity associated with continuing the second-stage duration of labor, weighing the probability of spontaneous vaginal birth without morbidity compared with birth with serious maternal or neonatal complications.Methods: In a retrospective cohort, we analyzed singleton, vertex births at 36 weeks of gestation or greater without prior cesarean delivery (n=43,810 nulliparous and 59,605 multiparous women). We calculated rates of spontaneous vaginal birth and composite serious maternal or neonatal complications. Results were stratified by parity (nulliparous or multiparous) and epidural status (yes or no). Competing risks models were created for 1) spontaneous vaginal birth with no morbidity, 2) birth with maternal or neonatal morbidity, and 3) no spontaneous vaginal birth and no morbidity, and our main interest was in comparing number 1 against number 2.Results: Rates of spontaneous vaginal birth without morbidity were slightly higher after the first half hour (greater than 0.5-1.0 hours) for nulliparous women, after which rates decreased with increasing second-stage duration. For multiparous women, rates of spontaneous vaginal birth without morbidity decreased with increasing second-stage duration. For illustration, for a nulliparous woman with an epidural at 3.0 hours of the second stage of labor who extended by another 1.0 hour, her likelihood of delivering by spontaneous vaginal birth was 31.4% compared with her likelihood of birth with any serious complication in the subsequent hour, which was 7.6%. The percentage of cesarean deliveries for nonreassuring fetal heart rate tracing were higher for women without compared with women with an epidural.Conclusion: Rates of spontaneous vaginal birth without serious morbidity steadily decreased for increasing second-stage duration except for the first half hour for nulliparous women. We did not observe an inflection point at a particular hour mark for either spontaneous vaginal delivery without morbidity or births with morbidity. Our findings will assist in decision-making for extending second-stage duration. [ABSTRACT FROM AUTHOR]

Objective: To estimate the association of pregnancy loss with common air pollutant exposure. Ambient air pollution exposure has been linked to adverse pregnancy outcomes, but few studies have investigated its relationship with pregnancy loss.Design: Prospective cohort study.Setting: Not applicable.Patient(s): A total of 343 singleton pregnancies in a multisite prospective cohort study with detailed protocols for ovulation and pregnancy testing.Intervention(s): None.Main Outcome Measure(s): Timing of incident pregnancy loss (from ovulation).Result(s): The incidence of pregnancy loss was 28% (n = 98). Pollutant levels at women's residences were estimated using modified Community Multiscale Air Quality models and averaged during the past 2 weeks (acute) and the whole pregnancy (chronic). Adjusted Cox proportional hazards models showed that an interquartile range increase in average whole pregnancy ozone (hazard ratio [HR] 1.12, 95% confidence interval [CI] 1.07-1.17) and particulate matter <2.5 μm (HR 1.13, 95% CI 1.03-1.24) concentrations were associated with faster time to pregnancy loss. Sulfate compounds also appeared to increase risk (HR 1.58, 95% CI 1.07-2.34). Last 2 weeks of exposures were not associated with loss.Conclusion(s): In a prospective cohort of couples trying to conceive, we found evidence that exposure to air pollution throughout pregnancy was associated with loss, but delineating specific periods of heightened vulnerability await larger preconception cohort studies with daily measured air quality. [ABSTRACT FROM AUTHOR]

Using a population-based birth cohort in upstate New York (2008–2010), we examined the determinants of brain-derived neurotrophic factor (BDNF) measured in newborn dried blood spots (n = 2,637). We also examined the association between neonatal BDNF and children's development. The cohort was initially designed to examine the influence of infertility treatment on child development but found no impact. Mothers rated children's development in five domains repeatedly through age 3 years. Socioeconomic and maternal lifestyle determinants of BDNF were examined using multivariable linear regression models. Generalized linear mixed models estimated odds ratios for neonatal BDNF in relation to failing a developmental domain. Smoking and drinking in pregnancy, nulliparity, non-White ethnicity/race, and prepregnancy obesity were associated with lower neonatal BDNF. Neonatal BDNF was not associated with failure for developmental domains; however, there was an interaction between BDNF and preterm birth. In preterm infants, a higher BDNF was associated with lower odds of failing any developmental domains, after adjusting for confounders and infertility treatment. This result was particularly significant for failure in communication. Our findings suggest that BDNF levels in neonates may be impacted by maternal lifestyle characteristics. More specifically, lower neonatal BDNF might be an early marker of aberrant neurodevelopment in preterm infants. [ABSTRACT FROM AUTHOR]

BACKGROUND: Human exposure to parabens and other antimicrobial chemicals is continual and pervasive. The hormone-disrupting properties of these environmental chemicals may adversely affect human reproduction. OBJECTIVE: We aimed to prospectively assess couples' urinary concentrations of antimicrobial chemicals in the context of fecundity, measured as time to pregnancy (TTP). METHODS: In a prospective cohort of 501 couples, we examined preconception urinary chemical concentrations of parabens, triclosan and triclorcarban in relation to TTP; chemical concentrations were modeled both continuously and in quartiles. Cox's proportional odds models for discrete survival time were used to estimate fecundability odds ratios (FORs) and 95% confidence intervals (CIs) adjusting for a priori-defined confounders. In light of TTP being a couple-dependent outcome, both partner and couple-based exposure models were analyzed. In all models, FOR estimates < 1.0 denote diminished fecundity (longer TTP). RESULTS: Overall, 347 (69%) couples became pregnant. The highest quartile of female urinary methyl paraben (MP) concentrations relative to the lowest reflected a 34% reduction in fecundity (aFOR = 0.66; 95% CI: 0.45, 0.97) and remained so when accounting for couples' concentrations (aFOR = 0.63; 95% CI: 0.41, 0.96). Similar associations were observed between ethyl paraben (EP) and couple fecundity for both partner and couple-based models (p-trend = 0.02 and p-trend = 0.05, respectively). No associations were observed with couple fecundity when chemicals were modeled continuously. CONCLUSIONS: Higher quartiles of preconception urinary concentrations of MP and EP among female partners were associated with reduced couple fecundity in partner-specific and couple-based exposure models. CITATION: Smarr MM, Sundaram R, Honda M, Kannan K, Buck Louis GM. 2016. Urinary concentrations of parabens and other antimicrobial chemicals and their association with couples' fecundity. Environ Health Perspect 124:730-736; http://dx.doi.org/10.1289/EHP189 [ABSTRACT FROM AUTHOR]

Study Question: Is couples' body compositions associated with reduced fecundity as measured by a longer time-to-pregnancy (TTP)?Summary Answer: Couples whose BMI are within obese class II (≥35 kg/m2) have a longer TTP in comparison to leaner (BMI < 25 kg/m2) couples, observed only when both partner's BMI was jointly modeled.What Is Known Already: Extremes of BMI have been associated with a longer TTP and with less successful assisted reproductive technology (ART) outcomes. To our knowledge, the association between measured adiposity in both partners of the couple and prospectively measured TTP has not been investigated despite pregnancy being a couple-dependent outcome.Study Design, Size, Duration: Prospective cohort with preconception recruitment of 501 couples trying for pregnancy and recruited from 16 counties in Michigan and Texas between 2005 and 2009. Couples were followed daily for up to a year of trying or until a hCG pregnancy.Participants/materials, Setting, Methods: In-home standardized anthropometric assessment of couples upon enrollment included measured height and weight using calibrated stadiometers and scales, and measured waist and hip circumferences. Discrete-time Cox regression was used to estimate fecundability odds ratios (FORs) and 95% CIs, controlling for potential confounders including age, number of days of vigorous physical activity, serum cotinine concentration, race, education, free cholesterol levels for each partner in partner-specific models and for both partners in couple-based models as well as average acts of intercourse per menstrual cycle and menstrual cycle regularity.Main Results and the Role Of Chance: Neither male nor female partner's BMI was associated with TTP when modeled individually. However, obese class II (BMIs ≥ 35.0 kg/m2) couples experienced a reduction in fecundability in both unadjusted (FOR = 0.45; 95% CI: 0.23, 0.89) and adjusted analyses (aFOR = 0.41; 95% CI: 0.17, 0.98) resulting in a longer TTP in comparison to couples with normal BMI (<25 kg/m2). Female partners' waist circumference ≥88.6 cm was associated with a significant reduction in fecundability in the unadjusted model (FOR = 0.64; 95% CI: 0.48, 0.86) but not in the adjusted model (aFOR = 0.77; 95% CI: 0.55, 1.08) in comparison to females with a smaller (<80 cm) circumference.Limitations, Reasons For Caution: BMI and waist circumference are proxy measures of body composition and residual confounding cannot be eliminated. Findings may not be generalizable to clinical populations.Wider Implications Of the Findings: This is the first cohort study known to us with preconception enrollment of couples who underwent standardized anthropometric assessment and for whom TTP was prospectively measured. The findings underscore the importance of considering both partners' body composition for fecundity outcomes and preconception guidance.Study Funding/competing Interest(s): Supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (Contracts #N01-HD-3-3355, N01-HD-3-3356 and N01-HD-3-3358). The authors have no competing interests.Trial Registration Number: N/A. [ABSTRACT FROM AUTHOR]

We aimed to study the potential impact of proximity to major roadways on time-to-pregnancy and infertility in couples attempting pregnancy in the Longitudinal Investigation of Fertility and Environment (LIFE) study (2005–2009), a population-based, prospective cohort study. Couples attempting pregnancy (n = 500) were enrolled and followed prospectively until pregnancy or 12 months of trying and 393 couples (78%) had complete data and full follow-up. Time-to-pregnancy was based on a standard protocol using fertility monitors, tracking estrone-3-glucuonide and luteinizing hormone, and pregnancy test kits to detect human chorionic gonadotropin (hCG). The fecundability odds ratio (FOR) and 95% confidence interval (CI) were estimated using proportional odds models. Infertility was defined as 12 months of trying to conceive without an hCG pregnancy and the relative risk (RR) and 95% CI were estimated with log-binomial regression. Final models were adjusted for age, parity, study site, and salivary alpha-amylase, a stress marker. Infertile couples (53/393; 14%) tended to live closer to major roadways on average than fertile couples (689 m vs. 843 m, respectively) but the difference was not statistically significant. The likelihood of pregnancy was increased 3% for every 200 m further away the couples residence was from a major roadway (FOR = 1.03; CI = 1.01–1.06). Infertility also appeared elevated at moderate distances compared to 1000 m or greater, but estimates lacked precision. Our findings suggest that proximity to major roadways may be related to reductions in fecundity. Prospective data from larger populations is warranted to corroborate these findings. [ABSTRACT FROM AUTHOR]

Study Question: What is the relationship between couple's health and fecundity in a preconception cohort?Summary Answer: Somatic health may impact fecundity in men and women as couples whose male partner had diabetes or whose female partner had two or more medical conditions had a longer time-to-pregnancy (TTP).What Is Already Known: The impact of somatic health on human fecundity is hypothesized given the reported declines in spermatogenesis and ovulation among individuals with certain medical comorbidities.Study Design, Size, Duration: A population-based prospective cohort study recruiting couples from 16 counties in Michigan and Texas (2005-2009) using sampling frameworks allowing for identification of couples planning pregnancy in the near future. Five hundred and one couples desiring pregnancy and discontinuing contraception were followed-up for 12 months or until a human chorionic gonadotropin pregnancy was detected.Participants/materials, Settings, Methods: In all, 33 (21.4%) female and 41 (26.6%) male partners had medical conditions at baseline.Main Results and the Role Of Chance: Couples' medical comorbidity was associated with pregnancy status. Diabetes in either partner was associated with diminished fecundity, as measured by a longer TTP. Specifically, fecundability odds ratios (FORs) were below 1, indicating a longer TTP, for male partners with diabetes (0.35, 95% confidence interval (CI): 0.14-0.86) even in adjusted models (0.35, 95% CI: 0.13-0.88). Female partners with diabetes had comparable reductions in FORs; however, the analyses did not reach statistical significance (0.26, 95% CI: 0.03-1.98). Female partners with two or more medical conditions had a significantly longer TTP compared with women with no health problems (0.36, 95% CI: 0.14-0.92). Importantly, the presence of medical conditions was not associated with sexual frequency. We cannot rule out residual confounding, Type 2 errors for less prevalent medical conditions, or chance findings in light of the multiple comparisons made in the analysis.Limitations, Reasons For Caution: The findings require cautious interpretation given that medical diagnoses are subject to possible reporting errors, although we are unaware of any potential biases that may have been introduced, as participants were unaware of how long it would take to become pregnant upon enrollment.Wider Implications Of the Findings: The current report suggests a relationship between male and female diabetes and fecundity, and possibly somatic health more globally. Moreover, while the mechanism is uncertain, if corroborated, our data suggest that early evaluation and treatment may be warranted for diabetics prior to attempting to conceive.Study Funding/competing Interests: Intramural research of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (Contract nos. #N01-HD-3-3355, N01-HD-3-3356 and N01-HD-3-3358). The authors have no conflicts of interest to declare. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We examined the longitudinal associations of age at achieving gross motor milestones and children's development in a US cohort of singletons and twins. METHODS: In the Upstate KIDS study, a population-based study of children born between 2008 and 2010, information on age at achievement of motor milestones and developmental skills was available in 599 children (314 singletons, 259 twins, and 26 triplets). Mothers reported their children's major motor milestones at ~4, 8, 12, 18, and 24 months. At age 4 years, children's development was clinically assessed by using the Battelle Developmental Inventory, Second Edition (BDI-2). Primary analyses by using multivariate linear regressions were conducted in singletons. We also examined the associations in twins. RESULTS: Later achievement of standing with assistance predicted lower BDI-2 scores in singletons in adjusted models (B per SD of age at achievement, -21.9 [95% confidence interval (CI), -41.5 to -2.2]). Post hoc analysis on age of standing with assistance showed that associations were driven by differences in adaptive skills (B = -5.3 [95% CI, -9.0 to -1.6]) and cognitive skills (B = -5.9 [95% CI, -11.5 to -0.4]). Analyses restricted to twins suggested no association between the age at achievement of milestones and total BDI-2 score after adjustment for gestational age and birth weight. CONCLUSIONS: This study provides evidence that the age of achieving motor milestones may be an important basis for various aspects of later child development. In twins, key predictors of later development (eg, perinatal factors) overshadow the predictive role of milestones in infancy. [ABSTRACT FROM AUTHOR]

Aim: We examined whether children of mothers with a medical condition diagnosed before or during pregnancy took longer to achieve gross motor milestones up to age 24 months.Method: We obtained information on medical conditions using self-reports, birth certificates, and hospital records in 4909 mothers participating in Upstate KIDS, a population-based birth cohort. Mothers reported on their children's motor milestone achievement at 4, 8, 12, 18, and 24 months of age.Results: After adjustment for covariates (including pre-pregnancy body mass index), children of mothers with gestational diabetes took longer to achieve sitting without support (hazard ratio [HR]=0.84, 95% confidence interval [CI] 0.75-0.93), walking with assistance (HR=0.88, 95% CI 0.77-0.98), and walking alone (HR=0.88, 95% CI 0.77-0.99) than children of females with no gestational diabetes. Similar findings emerged for maternal diabetes. Gestational hypertension was associated with a longer time to achieve walking with assistance. These associations did not change after adjustment for gestational age or birthweight. Severe hypertensive disorders of pregnancy were related to a longer time to achieve milestones, but not after adjustment for perinatal factors.Interpretation: Children exposed to maternal diabetes, gestational or pre-gestational, may take longer to achieve motor milestones than non-exposed children, independent of maternal obesity. [ABSTRACT FROM AUTHOR]

Menstrual cycle length (MCL) has been shown to play an important role in couple fecundity, which is the biologic capacity for reproduction irrespective of pregnancy intentions. However, a comprehensive assessment of its role requires a fecundity model that accounts for male and female attributes and the couple's intercourse pattern relative to the ovulation day. To this end, we employ a Bayesian joint model for MCL and pregnancy. MCLs follow a scale multiplied (accelerated) mixture model with Gaussian and Gumbel components; the pregnancy model includes MCL as a covariate and computes the cycle-specific probability of pregnancy in a menstrual cycle conditional on the pattern of intercourse and no previous fertilization. Day-specific fertilization probability is modeled using natural, cubic splines. We analyze data from the Longitudinal Investigation of Fertility and the Environment Study (the LIFE Study), a couple based prospective pregnancy study, and find a statistically significant quadratic relation between fecundity and menstrual cycle length, after adjustment for intercourse pattern and other attributes, including male semen quality, both partner's age, and active smoking status (determined by baseline cotinine level 100 ng/mL). We compare results to those produced by a more basic model and show the advantages of a more comprehensive approach. [ABSTRACT FROM AUTHOR]

The analysis of fecundity data is challenging and requires consideration of both highly timed and interrelated biologic processes in the context of essential behaviors such as sexual intercourse during the fertile window. Understanding human fecundity is further complicated by presence of a sterile population, i.e. couples unable to achieve pregnancy. Modeling techniques conducted to date have largely relied upon discrete time-to-pregnancy survival or day-specific probability models to estimate the determinants of time-to-pregnancy or acute effects, respectively. We developed a class of semi-parametric grouped transformation cure models that capture day-level variates purported to affect the cycle-level hazards of conception and, possibly, sterility. Our model's performance is assessed using simulation and longitudinal data from one of the few prospective cohort studies with preconception enrollment of women followed for 12 menstrual cycles at risk for pregnancy. [ABSTRACT FROM AUTHOR]

Prospective pregnancy studies are a valuable source of longitudinal data on menstrual cycle length. However, care is needed when making inferences of such renewal processes. For example, accounting for the sampling plan is necessary for unbiased estimation of the menstrual cycle length distribution for the study population. If couples can enroll when they learn of the study as opposed to waiting for the start of a new menstrual cycle, then due to length-bias, the enrollment cycle will be stochastically larger than the general run of cycles, a typical property of prevalent cohort studies. Furthermore, the probability of enrollment can depend on the length of time since a woman’s last menstrual period (a backward recurrence time), resulting in selection effects. We focus on accounting for length-bias and selection effects in the likelihood for enrollment menstrual cycle length, using a recursive two-stage approach wherein we first estimate the probability of enrollment as a function of the backward recurrence time and then use it in a likelihood with sampling weights that account for length-bias and selection effects. To broaden the applicability of our methods, we augment our model to incorporate a couple-specific random effect and time-independent covariate. A simulation study quantifies performance for two scenarios of enrollment probability when proper account is taken of sampling plan features. In addition, we estimate the probability of enrollment and the distribution of menstrual cycle length for the study population of the Longitudinal Investigation of Fertility and the Environment Study. [ABSTRACT FROM PUBLISHER]

Objective To examine preconception serum concentrations of perfluorooctanoic acid (PFOA) and six other PFCs in relation to gestational diabetes (GDM) risk. Design Prospective cohort with longitudinal follow-up. Setting Not applicable. Patient(s) Among 501 women recruited upon discontinuing contraception for the purpose of becoming pregnant, 258 (51%) became pregnant and were eligible for the study, of which 28 (11%) reported having physician-diagnosed GDM during follow-up. Intervention(s) None. Main Outcome Measure(s) The odds ratios (ORs) and 95% confidence intervals (CIs) of GDM associated with each standard deviation (SD) increment of preconception serum PFOA concentration (ng/mL, log-transformed) and six other PFCs were estimated with the use of logistic regression after adjusting for age, prepregnancy body mass index, smoking, and parity conditional on gravidity. Result(s) Preconception geometric mean (95% CI) PFOA concentrations (in ng/mL) were higher for women with than without GDM (3.94 [3.15–4.93] vs. 3.07 [2.83–3.12], respectively). Each SD increment in PFOA was associated with a 1.87-fold increased GDM risk (adjusted OR 1.86 [95% CI 1.14–3.02]). A slightly increased risk associated with each SD increment for the six other PFCs was observed as well (all ORs >1.0, range 1.06–1.27), although the associations were not statistically significant. Conclusion(s) Our findings suggested that higher environmentally relevant concentrations of PFOA were significantly associated with an increased risk of GDM. If corroborated, these findings may be suggestive of a possible environmental etiology for GDM. [ABSTRACT FROM AUTHOR]

Current duration data arise in cross-sectional studies from questions on the length of time from an initiating event to the time of interview. For example, in the National Survey on Family Growth, women who were considered at risk for pregnancy were asked (i) 'Are you currently attempting pregnancy?' and (ii) 'If yes, how many months have you been attempting to get pregnant?' The responses to (ii), referred to as the current durations, are length-biased because women with longer durations are more likely to answer yes to question (i) and therefore be included in the sample. Previous methods to analyze such data include continuous time nonparametric and parametric approaches. In this article, we propose a semiparametric Cox model and a piecewise constant baseline model (used to account for digit preference) to analyze grouped current duration data. We discuss and investigate through simulation studies, the robustness properties of the proposed methods when digit preference is present. Lastly, we present an analysis of the current duration data resulting from the 2002 National Survey on Family Growth. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Objective: To assess the relationship between environmental chemicals and couple fecundity or time to pregnancy (TTP). Design: Prospective cohort. Setting: Communities of targeted populations with reported exposure. Patient(s): 501 couples recruited upon discontinuing contraception to become pregnant, 2005–2009. Intervention(s): None. Main Outcome Measure(s): Fecundability odds ratios (FORs) and 95% confidence intervals (CIs) estimated for each partner’s chemical concentrations adjusted for age, body mass index, cotinine, creatinine, and research site while accounting for time off contraception. Result(s): Couples completed interviews and anthropometric assessments and provided the urine specimens for quantification of bisphenol A (BPA) and 14 phthalate metabolites, which were measured using high-performance liquid chromatography with electrospray triple-quadrupole mass spectrometer. Women recorded menstruation and pregnancy test results in daily journals. Couples were evaluated until a positive human-chorionic gonadotropin pregnancy test or 12 cycles without pregnancy. Neither female nor male BPA concentration was associated with TTP (FOR 0.98; 95% CI, 0.86, 1.13 and FOR 1.04; 95% CI, 0.91, 1.18, respectively). Men’s urinary concentrations of monomethyl, mono-n-butyl, and monobenzyl phthalates were associated with a longer TTP (FOR 0.80; 95% CI, 0.70, 0.93; FOR 0.82, 95% CI, 0.70, 0.97; and FOR 0.77, 95% CI, 0.65 0.92, respectively). Conclusion(s): Select male but not female phthalate exposures were associated with an approximately 20% reduction in fecundity, underscoring the importance of assessing both partners’ exposure to minimize erroneous conclusions. [Copyright &y& Elsevier]

Phytoestrogens have been associated with subtle hormonal changes, although effects on fecundity are unknown. Our objective was to evaluate the association between male and female urinary phytoestrogen (isoflavone and lignan) concentrations and time to pregnancy (TTP) in a population-based cohort of 501 couples desiring pregnancy and discontinuing contraception. Couples were followed for 12 mo or until pregnancy. Fecundability ORs (FORs) and 95%CIs were estimated after adjusting for age, body mass index, race, site, creatinine, supplement use, and physical activity in relation to female, male, and joint couple concentrations. Models included the phytoestrogen of interest and the sum of the remaining individual phytoestrogens. FORs <1 denote a longer TTP and FORs >1 a shorter TTP. Urinary lignan concentrations were higher, on average, among female partners of couples who became pregnant during the study compared with women who did not become pregnant (median enterodiol: 118 vs. 80 nmol/L; < 0.10; median P enterolactone: 990 vs. 412 nmol/L; < 0.05) and were associated with significantly shorter TTP in models based on both P individual and couples concentrations (couples' models: enterodiol FOR, 1.13; 95% CI: 1.02, 1.26; enterolactone FOR, 1.11; 95% CI: 1.01, 1.21). Male lignan concentrations were not associated with TTP, nor were isoflavone concentrations. Sensitivity analyses showed that associations observed are unlikely to be explained by potential unmeasured confounding by lifestyle or other nutrients. Our results suggest that female urinary lignan concentrations at levels characteristic of the U.S. population are associated with a shorter TTP among couples who are attempting to conceive, highlighting the importance of dietary influences on fecundity. [ABSTRACT FROM AUTHOR]

Objective: To assess semen parameters and couple fecundity as measured by time to pregnancy (TTP). Design: Observational prospective cohort with longitudinal measurement of TTP. Setting: Sixteen Michigan/Texas counties. Patient(s): A total of 501 couples discontinuing contraception were followed for 1 year while trying to conceive; 473 men (94%) provided one semen sample, and 80% provided two samples. Intervention(s): None. Main Outcome Measure(s): Using prospectively measured TTP, fecundability odds ratios (FORs) and 95% confidence intervals (CIs) were estimated for 36 individual semen quality parameters accounting for repeated semen samples, time off contraception, abstinence, enrollment site, and couples' ages, body mass indices, and serum cotinine concentrations. Result(s): In adjusted models, semen quality parameters were associated with significantly shorter TTP as measured by FORs >1: percent motility, strict and traditional morphology, sperm head width, elongation factor, and acrosome area. Significantly longer TTPs or FORs <1 were observed for morphologic categories amorphous and round sperm heads and neck/midpiece abnormalities. No semen quality parameters achieved significance when simultaneously modeling all other significant semen parameters and covariates, except for percent coiled tail when adjusting for sperm concentration (FOR 0.99; 95% CI 0.99–1.00). Male age was consistently associated with reduced couple fecundity (FOR 0.96; 95% CI 0.93–0.99), reflecting a longer TTP across all combined models. Female but not male body mass index also conferred a longer TTP (FOR 0.98; 95% CI 0.96–0.99). Conclusion(s): Several semen measures were significantly associated with TTP when modeled individually but not jointly and in the context of relevant couple-based covariates. [Copyright &y& Elsevier]

BACKGROUND: Evidence suggesting that persistent environmental pollutants may be reproductive toxicants underscores the need for prospective studies of couples for whom exposures are measured. OBJECTIVES: We examined the relationship between selected persistent pollutants and couple fecundity as measured by time to pregnancy. METHODS: A cohort of 501 couples who discontinued contraception to become pregnant was prospectively followed for 12 months of trying to conceive or until a human chorionic gonadotrophin (hCG) test confirmed pregnancy. Couples completed daily journals on lifestyle and provided biospecimens for the quantification of 9 organochlorine pesticides, 1 polybrominated biphenyl, 10 polybrominated diphenyl ethers, 36 polychlorinated biphenyls (PCBs), and 7 perfluorochemicals (PFCs) in serum. Using Cox models for discrete time, we estimated fecundability odds ratios (FORs) and 95% CIs separately for each partner’s concentrations adjusting for age, body mass index, serum cotinine, serum lipids (except for PFCs), and study site (Michigan or Texas); sensitivity models were further adjusted for left truncation or time off of contraception (≤ 2 months) before enrollment. RESULTS: The adjusted reduction in fecundability associated with standard deviation increases in log-transformed serum concentrations ranged between 18% and 21% for PCB congeners 118, 167, 209, and perfluorooctane sulfonamide in females; and between 17% and 29% for p,p´‑DDE and PCB congeners 138, 156, 157, 167, 170, 172, and 209 in males. The strongest associations were observed for PCB 167 (FOR 0.79; 95% CI: 0.64, 0.97) in females and PCB 138 (FOR = 0.71; 95% CI: 0.52, 0.98) in males. CONCLUSIONS: In this couple-based prospective cohort study with preconception enrollment and quantification of exposures in both female and male partners, we observed that a subset of persistent environmental chemicals were associated with reduced fecundity. [ABSTRACT FROM AUTHOR]

Background: The association between obesity (body mass index (BMI) 30 kg/m² ) and pattern of medication use during pregnancy in the United States is not well-studied. Higher pre-pregnancy BMI may be associated with increases or decreases in medication use across pregnancy as symptoms (e.g. reflux) or comorbidities (e.g. gestational diabetes) requiring treatment that may be associated with higher BMI could also change with advancing gestation. Objectives: To determine whether prenatal medication use, by the number and types of medications, varies by pre-pregnancy obesity status. Methods: In a secondary data analysis of a racially/ethnically diverse prospective cohort of pregnant women with low risk for fetal abnormalities enrolled in the first trimester of pregnancy and followed to delivery (singleton, 12 United States clinical sites), free text medication data were obtained at enrollment and up to five follow-up visits and abstracted from medical records at delivery. Results: In 436 women with obesity and 1750 women without obesity (pre-pregnancy BMI, 19–29.9 kg/m² ), more than 70% of pregnant women (77% of women with and 73% of women without obesity) reported taking at least one medication during pregnancy, respectively (adjusted risk ratio (aRR)=1.10, 95% confidence interval (CI)=1.01, 1.20), with 81% reporting two and 69% reporting three or more. A total of 17 classes of medications were identified. Among medication classes consumed by at least 5% of all women, the only class that differed between women with and without obesity was hormones and synthetic substitutes (including steroids, progesterone, diabetes, and thyroid medications) in which women with obesity took more medications (11 vs. 5%, aRR = 1.9, 95% CI = 1.38, 2.61) compared to women without obesity. Within this class, a higher percentage of women with obesity took diabetes medications (2.3 vs. 0.7%) and progesterone (3.4 vs. 1.3%) than their non-obese counterparts. Similar percentages of women with and without obesity reported consuming medications in the remaining medication classes including central nervous system agents (50 and 46%), gastrointestinal drugs (43 and 40%), anti-infective agents (23 and 21%), antihistamines (20 and 17%), autonomic drugs (10 and 9%), and respiratory tract agents (7 and 6%), respectively (p > 0.05 for all adjusted comparisons). There were no differences in medication use by obesity status across gestation. Since the study exclusion criteria limited the non-obese group to women without thyroid disease, in a sensitivity analysis we excluded all women who reported thyroid medication intake and still a higher proportion of women with obesity took the hormones and synthetic substitutes class compared to women without obesity. [ABSTRACT FROM AUTHOR]

Objective: To assess the association between self-reported measures of stress, anxiety, depression, and related constructs and fecundity. Design: Prospective cohort study of women trying to conceive. Setting: United Kingdom. Patient(s): Three hundred thirty-nine women aged 18–40 years who were attempting to conceive. Intervention(s): Completed daily diaries for up to six cycles or until pregnancy was detected. For each cycle, stress biomarkers were measured and psychosocial questionnaires were completed. Main Outcome Measures(s): Fecundability odds ratios (FORs) and 95% confidence intervals were calculated using discrete time survival methods, and the day-specific probabilities of pregnancy were calculated using Bayesian statistical techniques. Result(s): Among the 339 women, 207 (61%) became pregnant during the study, 69 (20%) did not become pregnant, and 63 (19%) withdrew. After controlling for maternal age, parity, months trying to conceive before enrollment, smoking, caffeine use, and frequency of intercourse, we found no association between most psychosocial measures and FORs or the day-specific probabilities of pregnancy save for an increased FOR for women reporting higher versus lower levels of social support. Conclusion(s): Self-reported psychosocial stress, anxiety, and depression were not associated with fecundity. Any adverse effect of stress or psychological disturbance on fecundity does not appear to be detectable via the questionnaires administered. [ABSTRACT FROM AUTHOR]

Abstract: The effect of heavy metals at environmentally relevant concentrations on couple fecundity has received limited study despite ubiquitous exposure. In 2005–2009, couples (n =501) desiring pregnancy and discontinuing contraception were recruited and asked to complete interviews and to provide blood specimens for the quantification of cadmium (μgL−1), lead (μgdL−1) and mercury (μgL−1) using inductively coupled plasma-mass spectrometry. Couples completed daily journals on lifestyle and intercourse along with menstruation and pregnancy testing for women. Couples were followed for 12months or until pregnant. Fecundability odds ratios (FORs) and 95% confidence intervals (CIs) were estimated adjusting for age, body mass index, cotinine, and serum lipids in relation to female then male exposures. FORs <1 denote a longer time to pregnancy. In adjusted models, reduced FORs were observed for both female cadmium (0.78; 95% CI 0.63–0.97) and male lead (0.85; 95% CI 0.73–0.98) concentrations. When jointly modeling couples’ exposures, only male lead concentration significantly reduced the FOR (0.82; 95% CI 0.68, 0.97), though the FOR remained <1 for female cadmium (0.80; 95% CI 0.64, 1.00). This prospective couple based cohort with longitudinal capture of time to pregnancy is suggestive of cadmium and lead’s reproductive toxicity at environmentally relevant concentrations. [Copyright &y& Elsevier]

Understanding conception probabilities is important not only for helping couples to achieve pregnancy but also in identifying acute or chronic reproductive toxicants that affect the highly timed and interrelated processes underlying hormonal profiles, ovulation, libido, and conception during menstrual cycles. Currently, 2 statistical approaches are available for estimating conception probabilities depending upon the research question and extent of data collection during the menstrual cycle: a survival approach when interested in modeling time-to-pregnancy (TTP) in relation to women or couples' purported exposure(s), or a hierarchical Bayesian approach when one is interested in modeling day-specific conception probabilities during the estimated fertile window. We propose a biologically valid discrete survival model that unifies the above 2 approaches while relaxing some assumptions that may not be consistent with human reproduction or behavior. This approach combines both the survival and the hierarchical models allowing investigators to obtain the distribution of TTP and day-specific probabilities during the fertile window in a single model. Our model allows for the consideration of covariate effects at both the cycle and the daily level while accounting for daily variation in conception. We conduct extensive simulations and utilize the New York State Angler Prospective Pregnancy Cohort Study to illustrate our approach. We also provide the code to implement the model in R software in the supplemental section of the supplementary material available at Biostatistics online. [ABSTRACT FROM PUBLISHER]

Summary McLain AC, Sundaram R, Cooney MA, Gollenberg AL, Buck Louis GM. Clustering of fecundability within women. Paediatric and Perinatal Epidemiology 2011; 25: 460-465. Adverse pregnancy outcomes have long been observed to cluster within women resulting in the inclusion of past reproductive history in clinical assessments and perinatal scoring systems. However, limited study has focused on the clustering of fecundability as measured by time to pregnancy (TTP), despite growing evidence suggestive of a possible association with adverse pregnancy outcomes known to cluster within women. We sought to empirically evaluate the clustering of conception delay, and TTP more globally, in one of the few existing prospective pregnancy cohort studies that captured women's successive pregnancies. The study cohort comprised 544 women who contributed 1119 pregnancies in the US Collaborative Perinatal Project. We used a discrete Cox frailty model to estimate the degree and significance of within-woman clustering of TTP. Women with an initial conception delay (TTP > 6 months) were older, less educated and had higher body mass indices than women not experiencing delays (TTP ≤ 6 months). Our analysis indicates that there is significant within-woman clustering of TTP (variance of the frailty = 0.80, [95% confidence interval 0.49, 1.11]) after adjusting for baseline maternal age, body mass index and education level. Similar to many other reproductive and perinatal outcomes, our findings suggest that TTP clusters within women. Identifying exposures or behaviours that affect TTP may offer strategies for reducing conception delay in future pregnancy attempts. [ABSTRACT FROM AUTHOR]

Human fecundability is defined as the probability of conception during a menstrual cycle among couples at risk for pregnancy. It is highly relevant for understanding human reproduction and represents a series of highly interrelated and timed processes. The statistical literature has recognized the need to incorporate both biological and behavioral factors (Barrett and Marshall, 1969; Dunson and Stanford, 2005) when modeling conception probabilities, given that intercourse during the fertile window is a necessary but not sufficient criterion for conception. The heterogeneity of behaviors such as the timing and frequency of intercourse in a menstrual cycle needs to be considered when estimating conception. Here we propose a joint model of intercourse behavior and human fecundability through a classic conception probability model and a structural equation model (SEM) to accommodate intercourse during the menstrual cycle. The SEM part of the proposed model allows the dependency between intercourse behaviors on consecutive days in a menstrual cycle to vary across days. Consequently, the proposed model can accommodate not only a broad variety of intercourse patterns and dependency structures but also general covariate effects. Finally, we present a detailed analysis of the New York State Angler Cohort Prospective Pregnancy Study to illustrate the proposed methodology. [ABSTRACT FROM PUBLISHER]

The Cox model with time-dependent coefficients has been studied by a number of authors recently. In this paper, we develop empirical likelihood (EL) pointwise confidence regions for the time-dependent regression coefficients via local partial likelihood smoothing. The EL simultaneous confidence bands for a linear combination of the coefficients are also derived based on the strong approximation methods. The EL ratio is formulated through the local partial log-likelihood for the regression coefficient functions. Our numerical studies indicate that the EL pointwise/simultaneous confidence regions/bands have satisfactory finite sample performances. Compared with the confidence regions derived directly based on the asymptotic normal distribution of the local constant estimator, the EL confidence regions are overall tighter and can better capture the curvature of the underlying regression coefficient functions. Two data sets, the gastric cancer data and the Mayo Clinic primary biliary cirrhosis data, are analysed using the proposed method. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies the estimation in the proportional odds model based on randomly truncated data. The proposed estimators for the regression coefficients include a class of minimum distance estimators defined through weighted empirical odds function. We have investigated the asymptotic properties like the consistency and the limiting distribution of the proposed estimators under mild conditions. The finite sample properties were investigated through simulation study making comparison of some of the estimators in the class. We conclude with an illustration of our proposed method to a well-known AIDS data. [Copyright &y& Elsevier]

Multistage models are used to describe individuals (or experimental units) moving through a succession of “stages” corresponding to distinct states (e.g., healthy, diseased, diseased with complications, dead). The resulting data can be considered to be a form of multivariate survival data containing information about the transition times and the stages occupied. Traditional survival analysis is the simplest example of a multistage model, where individuals begin in an initial stage (say, alive) and move irreversibly to a second stage (death). In this article, we consider general multistage models with a directed tree structure (progressive models) in which individuals traverse through stages in a possibly non-Markovian manner. We construct nonparametric estimators of stage occupation probabilities and marginal cumulative transition hazards. Empirical calculations of these quantities are not possible due to the lack of complete data. We consider current status information which represents a more severe form of censoring than the commonly used right censoring. Asymptotic validity of our estimators can be justified using consistency results for nonparametric regression estimators. Finite-sample behavior of our estimators is studied by simulation, in which we show that our estimators based on these limited data compare well with those based on complete data. We also apply our method to a real-life data set arising from a cardiovascular diseases study in Taiwan. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies a class of Cramér–von Mises type minimum distance estimators of the scale parameter in the two sample randomly left truncated scale models. The proposed class of estimators includes an analogue of the well-known Hodges–Lehmann estimator. The paper proves the asymptotic normality of these estimators under mild conditions. It also contains a real data application and a simulation study making a comparison of some of the estimators in the class with the ratio of the two means. [Copyright &y& Elsevier]

This work concerns the estimation of a smooth survival function based on doubly censored data. We establish strong consistency and asymptotic normality for a kernel estimator. Moreover, we also obtain an asymptotic expression for the mean integrated squared error, which yields an optimum bandwidth in terms of readily estimable quantities. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies estimation in the proportional odds model, with time-dependent covariates, based on right-censored data. The estimation procedure is an extension of the Yang and Prentice (J. Amer. Statist. Assoc. 94 (1999) 125) approach to the time-dependent covariate case. The proposed estimators include a class of minimum distance estimators defined through weighted empirical odds function. These estimators are shown to be strongly consistent and asymptotically normal, with variances that can be consistently estimated. It also contains a simulation study making comparison of some of the estimators in the class. [Copyright &y& Elsevier]

This paper studies estimation of scale parameter in the two sample doubly censored scale models. The proposed estimators include a class of Cramer–von Mises minimum distance estimators and the analog of the well celebrated Hodges–Lehmann estimator. The paper proves the asymptotic normality of these estimators under mild conditions and consistency of the minimum distance estimators is shown when the scale model is only approximately true. It also contains a simulation study making comparison of some of the estimators in the class with the ratio of the two means. [Copyright &y& Elsevier]

Objective: To evaluate whether children conceived using assisted reproductive technology (ART) or ovulation induction (OI) have greater cardiometabolic risk than children conceived without treatment.Design: Clinical assessments in 2018-2019 in the Upstate KIDS cohort.Setting: Clinical sites in New York.Patient(s): Three hundred thirty-three singletons and 226 twins from 448 families.Intervention(s): Mothers reported their use of fertility treatment and its specific type at baseline and approximately 4 months after delivery. High validity of the self-reported use of ART was previously confirmed. The children were followed up from infancy through 8-10 years of age. A subgroup was invited to participate in clinic visits.Main Outcome Measure(s): The measurements of blood pressure (BP), arterial stiffness using pulse wave velocity, anthropometric measures, and body fat using bioelectrical impedance analysis were performed (n = 559). The levels of plasma lipids, C-reactive protein, and hemoglobin A1c were measured using blood samples obtained from 263 children.Result(s): The average age of the children was 9.4 years at the time of the clinic visits Approximately 39% were conceived using fertility treatment (18% using ART and 21% using OI). Singletons conceived using fertility treatment (any type or using ART or OI specifically) did not statistically differ in systolic or diastolic BP, heart rate, or pulse wave velocity. Singletons conceived using OI were smaller than singletons conceived without treatment, but the average body mass index of the latter was higher (z-score: 0.41 [SD, 1.24]) than the national norms. Twins conceived using either treatment had lower BP than twins conceived without treatment. However, twins conceived using OI had significantly higher arterial stiffness (0.59; 95% CI, 0.03-1.15 m/s), which was attenuated after accounting for maternal BP (0.29; 95% CI, -0.03 to 0.46 m/s). Twins did not significantly differ in size or fat measures across the groups. The mode of conception was not associated with the levels of lipids, C-reactive protein, or glycosylated hemoglobin.Conclusion(s): Clinical measures at the age of 9 years did not indicate greater cardiometabolic risk in children conceived using ART or OI compared with that in children conceived without treatment.Clinical Trial Registration Number: ClinicalTrials.gov #NCT03106493. [ABSTRACT FROM AUTHOR]

Objective  This study aimed to describe the overall quantity and type of supplements and medications used during pregnancy in a low-risk cohort and to examine any racial/ethnic differences in intake. Study Design  We used data from 2,164 racially/ethnically diverse, nonobese, and low-risk pregnant women participating without pre-pregnancy chronic conditions in a prospective cohort study at 12 sites across the United States. Medication data were self-reported as free text in enrollment, follow-up visit questionnaires, and abstracted from medical records at delivery. Supplements and medications data were mapped to their active ingredients and categorized into corresponding classes using the Slone Drug Dictionary. The total number and classes of supplements and medications consumed during pregnancy were calculated. Modified Poisson regression models were used to estimate the racial/ethnic differences in supplements and medications intake. All models were adjusted for maternal sociodemographic factors and study site. Results  98% of women took at least one supplement during pregnancy, with prenatal vitamins/multivitamins being most common. While only 31% reported taking no medications during pregnancy, 23% took one, 18% took two, and 28% took three or more. The percentage of women taking at least one medication during pregnancy was highest among non-Hispanic white women and lowest among Asians (84 vs. 55%, p  < 0.001). All racial/ethnic groups reported taking the same top four medication classes including central nervous system agents, gastrointestinal drugs, anti-infective agents, and antihistamines. Compared with non-Hispanic white women, Hispanic (adjusted relative risk [aRR]: 0.84, 95% confidence interval [CI]: 0.71–0.98), and Asian women (aRR: 0.83, 95% CI: 0.70–0.98) were less likely to take central nervous system agents, as well as gastrointestinal drugs (Hispanics aRR: 0.79, 95% CI: 0.66–0.94; Asians aRR = 0.75, 95% CI: 0.63–0.90), and antihistamines (Hispanics aRR: 0.65, 95% CI: 0.47–0.92). Conclusion  Supplement intake was nearly universal. Medication use was also common among this low-risk pregnancy cohort and differed by race/ethnicity. ClinicalTrials.gov Identifier  NCT00912132. Key Points In women without chronic conditions, medication use is common. Racial/ethnic differences exist in prenatal medications use. Almost all women use supplements during pregnancy. [ABSTRACT FROM AUTHOR]

Background: Preterm birth is associated with lower neurocognitive performance. However, whether children's neurodevelopment improves with longer gestations within the full-term range (37-41 weeks) is unclear. Given the high rate of obstetric intervention in the USA, it is critical to determine whether long-term outcomes differ for children delivered at each week of term.Methods: This secondary analysis included 39 199 live-born singleton children of women who were admitted to the hospital in spontaneous labour from the US Collaborative Perinatal Project (1959-76). At each week of term gestation, we evaluated development at 8 months using the Bayley Scales of Infant Development, 4 years using the Stanford-Binet IQ (SBIQ) domains and 7 years using the Wechsler Intelligence Scales for Children (WISC) and Wide-Range Achievement Tests (WRAT).Results: Children's neurocognitive performance improved with each week of gestation from 37 weeks, peaking at 40 or 41 weeks. Relative to those delivered at 40 weeks, children had lower neurocognitive scores at 37 and 38 weeks for all assessments except SBIQ and WISC Performance IQ. Children delivered at 39 weeks had lower Bayley Mental (β = -1.18; confidence interval -1.77, -0.58) and Psychomotor (β = -1.18; confidence interval -1.90, -0.46) scores. Results were similar for within-family analyses comparing siblings, with the addition of lower WRAT scores at 39 weeks.Conclusions: The improvement in development scores across assessment periods indicates that each week up to 40 or 41 weeks of gestation is important for short- and long-term cognitive development, suggesting 40-41 weeks may be the ideal delivery window for optimal neurodevelopmental outcomes. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether deoxyribonucleic acid (DNA) methylation at birth and in childhood differ by conception using assisted reproductive technologies (ART) or ovulation induction compared with those in children conceived without fertility treatment.Design: Upstate KIDS is a matched exposure cohort which oversampled on newborns conceived by treatment.Setting: New York State (excluding New York City).Patient(s): This analysis included 855 newborns and 152 children at approximately 9 years of age.Intervention(s): None.Main Outcome Measure(s): DNA methylation levels were measured using the Illumina EPIC platform. Single CpG and regional analyses at imprinting genes were conducted.Result(s): Compared to no fertility treatment, ART was associated with lower mean DNA methylation levels at birth in 11 CpGs (located in/near SYCE1, SPRN, KIAA2013, MYO1D, GET1/WRB-SH4BGR, IGF1R, SORD, NECAB3/ACTL10, and GET1) and higher mean methylation level in 1 CpG (KLK4; all false discovery rate P<.05). The strongest association (cg17676129) was located at SYCE1, which codes for a synaptonemal complex that plays a role in meiosis and therefore infertility. This CpG remained associated with newborn hypomethylation when the analysis was limited to those conceived with ICSI, but this may be because of underlying male infertility. In addition, nine regions in maternally imprinted genes (IGF1R, PPIEL, SVOPL GNAS, L3MBTL, BLCAP, HYMAI/PLAGL1, SNU13, and MEST) were observed to have decreased mean DNA methylation levels among newborns conceived by ART. In childhood, hypomethylation of the maternally imprinted gene, GNAS, persisted. No CpGs or regions were associated with ovulation induction.Conclusion(s): ART but not ovulation induction was associated with hypomethylation at birth, but only one difference at an imprinting region appeared to persist in childhood. [ABSTRACT FROM AUTHOR]

Objective: To study the associations between maternal polycystic ovary syndrome (PCOS) and hirsutism with offspring attention-deficit/hyperactivity disorder (ADHD), anxiety, conduct disorder, and behavioral problems.Design: Prospective birth cohort study.Setting: Not applicable.Patient(s): A total of 1,915 mother-child dyads.Intervention(s): None.Main Outcome Measure(s): Maternal report of offspring ADHD, anxiety, or conduct disorder diagnosis at 7 to 8 years; emotional symptoms, behavioral problems (including peer relationship, conduct, hyperactivity/inattention), and prosocial problems measured with the Strengths and Difficulties Questionnaire (SDQ) at 7 years.Result(s): Prevalence of PCOS and hirsutism were 12.0% and 3.9%; 84% of women with hirsutism had PCOS. After adjustment for sociodemographic covariates, prepregnancy body mass index, and parental history of affective disorders, children born to mothers with PCOS had higher risk of anxiety (adjusted risk ratio [aRR] 1.62; 95% confidence interval [CI], 1.02-2.57) and borderline emotional symptoms (aRR 1.66; 95% CI, 1.18-2.33) compared with children born to mothers without PCOS. The associations between maternal PCOS and offspring ADHD were positive but imprecise. Maternal hirsutism was related to a higher risk of children's ADHD (aRR 2.33; 95% CI, 1.28-4.24), conduct disorder (aRR 2.54; 95% CI 1.18-5.47), borderline emotional symptoms, peer relationship problems, and conduct problems (aRRs 2.61; 95% CI, 1.69-4.05; 1.92; 95% CI, 1.16-3.17; and 2.22; 95% CI, 1.30-3.79, respectively).Conclusion(s): Maternal PCOS was associated with offspring anxiety, and hirsutism was related to other offspring behavioral problems. These findings should be interpreted with caution as replication is needed in prospective cohort studies that assess PCOS and hirsutism diagnoses using medical records. [ABSTRACT FROM AUTHOR]