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Background: Maternal overweight and obesity affect two-thirds of women of childbearing age and may increase the risk of impaired child cognition.Objective: Our objective was to test the hypothesis that high/low gestational weight gain (GWG) and high/low prepregnancy BMI were associated with offspring intelligence quotient (IQ) and executive function at age 10.Methods: Mother-infant dyads (n = 763) enrolled in a birth cohort study were followed from early pregnancy to 10 y postpartum. IQ was assessed by trained examiners with the use of the Stanford Binet Intelligence Scale-4th edition. Executive function was assessed by the number of perseverative errors on the Wisconsin Card Sorting Test and time to complete Part B on the Trail Making Test. Self-reported total GWG was converted to gestational-age-standardized GWG z score. Multivariable linear regression and negative binomial regression were used to estimate independent and joint effects of GWG and BMI on outcomes while adjusting for covariates.Results: At enrollment, the majority of women in the Maternal Health Practices and Child Development cohort were unmarried and unemployed, and more than one-half reported their race as black. The mean ± SD GWG z score was -0.5 ± 1.8, and 27% of women had a pregravid BMI ≥ 25. The median (IQR) number of perseverative errors was 23 (17, 29), the mean ± SD time on Part B was 103 ± 42.6 s, and 44% of children had a low average IQ (≤ 89). Maternal obesity was associated with 3.2 lower IQ points (95% CI: -5.6, -0.8) and a slower time to complete the executive function scale Part B (adjusted β: 12.7 s; 95% CI: 2.8, 23 s) compared with offspring of normal-weight mothers. Offspring of mothers whose GWG was >+1 SD, compared with -1 to +1 SD, performed 15 s slower on the executive function task (95% CI: 1.8, 28 s). There was no association between GWG z score and offspring composite IQ score (adjusted β: -0.32; 95% CI: -0.72, 0.10). Prepregnancy BMI did not modify these associations.Conclusions: Although GWG may be important for executive function, maternal BMI has a stronger relation than GWG to both offspring intelligence and executive function. Our findings contribute to evidence linking maternal obesity to long-term child outcomes. [ABSTRACT FROM AUTHOR]

Background: In high-income countries, maternal obesity is one of the most important modifiable causes of stillbirth, yet the pathways underpinning this association remain unclear. Objective: We estimated the association between maternal prepregnancy body mass index (BMI) and the risk of stillbirth defined by pathophysiologic contributors or causes. Design: Using a case-cohort design, we randomly sampled 1829 singleton deliveries from a cohort of 68,437 eligible deliveries at Magee-Womens Hospital in Pittsburgh, Pennsylvania (2003-2010), and augmented it with all remaining cases of stillbirth for a total of 658 cases. Stillbirths were classified based on probable cause(s) of death (maternal medical conditions, obstetric complications, fetal abnormalities, placental diseases, and infection). A panel of clinical experts reviewed medical records, placental tissue slides and pathology reports, and fetal postmortem reports of all stillbirths. Causes of fetal death were assigned by using the Stillbirth Collaborative Research Network Initial Causes of Fetal Death protocol from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Proportional hazards models were used to estimate the BMI-stillbirth association after adjustment for confounders. Results: The rate of stillbirth among lean, overweight, obese, and severely obese women was 7.7, 10.6, 13.9, and 17.3 per 1000 liveborn and stillborn infants, respectively. Adjusted stillbirth HRs (95% CIs) were 1.4 (1.1, 1.8) for overweight, 1.8 (1.3, 2.4) for obese, and 2.0 (1.5, 2.8) for severely obese women, respectively, compared with lean women; associations strengthened when limited to antepartum stillbirths. Obesity and severe obesity were associated with stillbirth resulting from placental diseases, hypertension, fetal anomalies, and umbilical cord abnormalities. BMI was not related to stillbirth caused by placental abruption, obstetric conditions, or infection. Conclusions: Multiple mechanisms appear to link obesity to stillbirth. Interventions to reduce stillbirth among obese mothers should consider targeting stillbirth due to hypertension and placental diseases—the most common causes of fetal death in this at-risk group. [ABSTRACT FROM AUTHOR]

Background: Excessive gestational weight gain (GWG) increases the risk of childhood obesity, but little is known about its association with infant growth patterns. Aim: The aim of this study was to examine the association between GWG and infant growth patterns. Methods: Pregnant women (n = 743) self-reported GWG at delivery, which we classified as inadequate, adequate or excessive based on the current guidelines. Offspring weight-for-age z-score (WAZ), length-for-age z-score (LAZ (with height-for-age (HAZ) in place of length at 36 months)) and body mass index z-score (BMIZ) were calculated at birth, 8, 18 and 36 months using the 2006 World Health Organization growth standards. Linear mixed models estimated the change in z-score from birth to 36 months by GWG. Results: The mean (SD) WAZ was -0.22 (1.20) at birth. Overall, WAZ and BMIZ increased from birth to, approximately, 24 months and decreased from 24 to 36 months, while LAZ/HAZ decreased from birth through 36 months. Excessive GWG was associated with higher offspring WAZ and BMIZ at birth, 8 and 36 months, and higher HAZ at 36 months, compared with adequate GWG. Compared with the same referent, inadequate GWG was associated with smaller WAZ and BMIZ at birth and 8 months. Conclusion: Excessive GWG may predispose infants to obesogenic growth patterns, while inadequate GWG may not have a lasting impact on infant growth. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Maternal vitamin D status in pregnancy is linked to foetal growth and may impact infant growth. Aim: This study examined the association between maternal vitamin D status and infant anthropometry. Subjects and methods: Data came from n = 2473 mother-child pairs from the 12-site US Collaborative Perinatal Project (1959-1965). Maternal serum 25-hydroxyvitamin D (25(OH)D) was measured at ≤ 26 weeks gestation. Multivariate-adjusted linear mixed models were used to relate maternal vitamin D status to infant z-scores for length (LAZ), head circumference (HCZ), weight (WAZ) and BMI (BMIZ), measured at birth and 4, 8 and 12 months. Results: Infants with maternal 25(OH)D ≥30 nmol/L vs <30 nmol/L had LAZ and HCZ measures 0.13 (95% CI = 0.03-0.23) and 0.20 (95% CI = 0.11-0.28) units higher, respectively, across the first year of life. Similar differences in WAZ and BMIZ at birth were resolved by 12 months of age due to interactions indicating steeper age slopes in infants with maternal 25(OH)D <30 nmol/L. Conclusion: Low maternal vitamin D status was associated with deficits at birth in infant weight and BMI that were recouped across the first year of life; associations with reduced measures of linear and skeletal growth were sustained from birth to 12 months. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To estimate the association between maternal 25-hydroxyvitamin D concentrations and risk of preterm birth subtypes. METHODS: We performed a case-cohort study using data and banked samples from patients at a teaching hospital in Pittsburgh, Pennsylvania. Eligible participants were women with a prenatal aneuploidy screening serum sample at or before 20 weeks of gestation who subsequently delivered a singleton, liveborn neonate. Of the 12,861 eligible women, we selected 2,327 at random as well as all remaining preterm birth cases for a total of 1,126 cases. Serum 25-hydroxyvitamin D was measured using liquid chromatography-tandem mass spectrome-try. Multivariable log-binomial regression models were used to estimate associations between maternal vitamin D status and preterm birth at 37 weeks of gestation (separately by spontaneous or indicated) and preterm birth at less than 34 weeks of gestation. RESULTS: The incidence of preterm birth at less than 37 weeks of gestation was 8.6% overall and 11.3%, 8.6%, and 7.3% among mothers with serum 25-hydroxyvitamin D less than 50, 50-74.9, and 75 nmol/L or greater, respectively (P<.01). After adjustment for maternal race and ethnicity, prepregnancy body mass index, season, smoking, and other confounders, the risk of preterm birth at less than 37 weeks of gestation significantly decreased as 25-hydroxyvitamin D increased to approximately 90 nmol/L and then plateaued (test of nonlinearity P<.01). Results were similar when limiting to cases that were medically indicated or occurred spontaneously and cases occurring at less than 34 weeks of gestation. CONCLUSION: Our data support a protective association maternal vitamin D sufficiency and preterm birth that combined with extant epidemiologic data may provide justification for a randomized clinical trial of maternal vitamin D replacement or supplementation to prevent preterm birth. [ABSTRACT FROM AUTHOR]

Background Conventional measures of gestational weight gain ( GWG) are correlated with pregnancy duration, and may induce bias to studies of GWG and perinatal outcomes. A maternal weight-gain-for-gestational-age z-score chart is a new tool that allows total GWG to be classified as a standardised z-score that is independent of gestational duration. Our objective was to compare associations with perinatal outcomes when GWG was assessed using gestational age-standardised z-scores and conventional GWG measures. Methods We studied normal-weight ( n = 522 120) and overweight ( n = 237 923) women who delivered liveborn, singleton infants in Pennsylvania, 2003-11. GWG was expressed using gestational age-standardised z-scores and three traditional measures: total GWG (kg), rate of GWG (kg per week of gestation), and the GWG adequacy ratio (observed GWG/ GWG recommended by the Institute of Medicine). Log-binomial regression models were used to assess associations between GWG and preterm birth, and small- and large-for-gestational-age births, while adjusting for race/ethnicity, education, smoking, and other confounders. Results The association between GWG z-score and preterm birth was approximately U-shaped. The risk of preterm birth associated with weight gain <10th percentile of each measure was substantially overestimated when GWG was classified using total kilogram and was moderately overestimated using rate of GWG or GWG adequacy ratio. All GWG measures had similar associations with small- or large-for-gestational-age birth. Conclusions Our findings suggest that studies of gestational age-dependent outcomes misspecify associations if total GWG, rate of GWG, or GWG adequacy ratio are used. The potential for gestational age-related bias can be eliminated by using z-score charts to classify total GWG. [ABSTRACT FROM AUTHOR]

Objective: To explore whether state restrictions on Medicaid funding for pregnancy termination of anomalous fetuses could be contributing to the black-white disparity in infant death resulting from congenital anomalies.Methods: Data on deaths resulting from anomalies were obtained from U.S. vital statistics records (1983-2004) and the Nationwide Inpatient Sample (2003-2007). We conducted an ecological study using Poisson and logistic regression to explore the association between state Medicaid funding for pregnancy terminations of anomalous fetuses and infant death resulting from anomalies by calendar time, race, and individual Medicaid status.Results: Since 1983, a gap in anomaly-related infant death has developed between states without compared with those with Medicaid funding for pregnancy termination (rate ratio in 2004 1.21, 95% confidence interval [CI] 1.18-1.24; crude risks: 146.8 compared with 121.7/100,000). Blacks were significantly more likely than whites to be on Medicaid (60.2% compared with 29.2%) and to live in a state without Medicaid funding for pregnancy termination (65.8% compared with 59.6%). The increased risk of anomaly-related death associated with lack of state Medicaid funding for pregnancy termination was most pronounced among black women on Medicaid (relative risk 1.94, 95% CI 1.52-2.36; crude risks: 245.5 compared with 129.3/100,000).Conclusion: States without Medicaid funding for pregnancy termination of anomalous fetuses have higher rates of infant death resulting from anomalies than those with funding, and this difference is most pronounced among black women on Medicaid. Restrictions on Medicaid funding for termination of anomalous fetuses potentially could be contributing to the black-white disparity in anomaly-related infant death.Level Of Evidence: II. [ABSTRACT FROM AUTHOR]

Background: Although poor sleep health is associated with weight gain and obesity in the non‐pregnant population, research on the impact of sleep health on weight change among pregnant people using a multidimensional sleep health framework is needed. Objectives: This secondary data analysis of the Nulliparous Pregnancy Outcome Study: Monitoring Mothers‐to‐be Sleep Duration and Continuity Study (n = 745) examined associations between mid‐pregnancy sleep health indicators, multidimensional sleep health and gestational weight gain (GWG). Methods: Sleep domains (i.e. regularity, nap duration, timing, efficiency and duration) were assessed via actigraphy between 16 and 21 weeks of gestation. We defined 'healthy' sleep in each domain with empirical thresholds. Multidimensional sleep health was based on sleep profiles derived from latent class analysis and composite score defined as the sum of healthy sleep domains. Total GWG, the difference between self‐reported pre‐pregnancy weight and the last measured weight before delivery, was converted to z‐scores using gestational age‐ and BMI‐specific charts. GWG was defined as low (<−1 SD), moderate (−1 or +1 SD) and high (>+1 SD). Results: Nearly 50% of the participants had a healthy sleep profile (i.e. healthy sleep in most domains), whereas others had a sleep profile defined as having varying degrees of unhealthy sleep in each domain. The individual sleep domains were associated with a 20%–30% lower risk of low or high GWG. Each additional healthy sleep indicator was associated with a 10% lower risk of low (vs. moderate), but not high, GWG. Participants with late timing, long duration and low efficiency (vs. healthy) profiles had the strongest risk of low GWG (relative risk 1.5, 95% confidence interval 0.9, 2.4). Probabilistic bias analysis suggested that most associations between individual sleep health indicators, sleep health profiles and GWG were biased towards the null. Conclusions: Future research should determine whether sleep health is an intervention target for healthy GWG. [ABSTRACT FROM AUTHOR]

A strength of SuperLearner is that it may accommodate key interactions between model variables without a priori specification. In prior research, protective associations between fruit intake and preeclampsia were stronger when estimated using SuperLearner with targeted maximum likelihood estimation (TMLE) compared with multivariable logistic regression without any interaction terms. We explored whether heterogeneity (i.e., differences in the effect estimate due to interactions between fruit intake and covariates) may partly explain differences in estimates from these two models. Using a U.S. prospective pregnancy cohort (2010–2013, n = 7781), we estimated preeclampsia risk differences (RDs) for higher versus lower fruit density using multivariable logistic regression and included two-way statistical interactions between fruit density and each of the 25 model covariates. We compared the RDs with those from SuperLearner with TMLE (gold standard) and logistic regression with no interaction. From the logistic regression models with two-way statistical interactions, 48% of the preeclampsia RDs were ≤−0.02 (closer to SuperLearner with TMLE estimate); 40% equaled −0.01 (same as logistic regression with no interaction estimate); the minority of RDs were at or crossed the null. Our exploratory analysis provided preliminary evidence that heterogeneity may partly explain differences in estimates from logistic regression versus SuperLearner with TMLE. • Heterogeneity is differences in effect estimates from exposure-covariate interactions. • SuperLearner, a machine learning method, may better accommodate such interactions. • The estimate from logistic regression without interaction differed from SuperLearner. • Those from logistic regression with interactions were more similar to SuperLearner. • Our findings support heterogeneity may partly explain differences among the models. [ABSTRACT FROM AUTHOR]

Objective: Marijuana use may pose risks for reproductive and perinatal health.1,2 Marijuana use among pregnant and reproductive-aged women increased 62% in the last decade.3 Our objective was to investigate time trends in perception of risk of regular marijuana use among U.S. pregnant and non-pregnant reproductive-age women.Study Design: We analyzed National Survey on Drug Use and Health (NSDUH) data from 2005-2015, a nationally representative survey on substance use in the civilian, non-institutionalized U.S.Population: 4 Data were collected using computer-assisted self-interviewing techniques to maximize privacy and confidentiality. We included female respondents ages 18-44 who were pregnant (unweighted N=8,713) or not pregnant (unweighted N=161,902). Respondents were asked: "How much do people risk harming themselves physically and in other ways when they smoke marijuana once or twice a week?" Possible responses included "No risk", "Slight risk," "Moderate risk," "Great risk", or "Don't Know." We calculated time trends in respondents answering "No risk." We used logistic regression to examine annual changes in the perception of no risk of regular marijuana use, adjusted for age, race/ethnicity, education, pregnancy status, and marijuana use within the prior 30 days. Average predicted probabilities of perceiving no risk of regular marijuana use were derived from regression models to show adjusted changes in risk perception over time among pregnant and non-pregnant women, by marijuana use status. Analyses were weighted to account for the complex survey design. The NSDUH are deidentified, publicly available data, and this study did not require IRB approval.Results: The average predicted probability of reporting no risk of regular marijuana use among all women increased from 4.6% in 2005 (95% CI: 4.2,5.0) to 19.0% in 2015 (95% CI: 18.3,19.7). Among women who did not report marijuana use in the prior 30 days, the average predicted probability of reporting no risk of regular marijuana use increased from 3.5% (95% CI: 3.0,3.9) to 16.5% (95% CI: 14.9,18.1) among pregnant women and from 3.1% (95% CI: 2.8,3.4) to 14.8% (95% CI: 14.0,15.5) among non-pregnant women (Figure). Among women who reported marijuana use in the prior 30 days, the average predicted probability of reporting no risk of regular marijuana use increased from 25.8% (95% CI: 23.0,28.7) to 65.4% (95% CI: 62.5,68.4) among pregnant women and from 23.7% (95% CI: 21.8,25.6) to 62.6% (95% CI: 61.0,64.3) among non-pregnant women. The probability of women reporting no risk of daily cigarette smoking also increased over time (1.1% in 2005 vs. 3.4% in 2015; data not shown), although this increase was far smaller than that observed for marijuana use.Conclusion: Perception that regular marijuana use has no risk has increased threefold from 2005-2015 among U.S. reproductive-age women. Pregnant and non-pregnant women who used marijuana in the prior 30 days more commonly perceived that regular use had no risk, relative to women who had no such marijuana use. However, perception that regular marijuana use has no risk increased even among women without marijuana use in the prior 30 days. We relied on self-reported marijuana use, which might underestimate the true prevalence. Women were asked about perception of risk of marijuana use generally, and not specifically about perinatal marijuana use. As 30 states have laws permitting medical or recreational marijuana, it is important to understand patterns in women's perceptions of the risks of regular marijuana use. Findings support the importance of investigating the effects of marijuana use on reproductive health. [ABSTRACT FROM AUTHOR]

Background Animal studies have linked in utero vitamin D exposure to various aspects of offspring brain development. Limited research has translated these findings to humans, and none have employed cord blood to measure exposure late in gestation. Methods Our objective was to examine the associations between maternal 25( OH) D measured at ≤26 weeks' gestation or cord blood 25( OH) D and offspring global development, IQ, achievement, and behaviour in the US Collaborative Perinatal Project (1959-73). This was a secondary analysis of data from a case-cohort study, with 3896 women and children who participated in at least one outcome assessment. Psychologists assessed global development at 8 months, IQ and behaviour at 4 and 7 years, and achievement at 7 years. Multiple linear and logistic regression was used to examine the associations between 25( OH) D and child outcomes, controlling for maternal education, age, parity, race, maternal body mass index, marital status, smoking, gestational age and month of blood draw, and study site. Results Positive associations for many outcomes were greatly attenuated upon adjustment for confounders and were generally null. Only IQ at age 7 was associated with both maternal and cord blood 25( OH) D, but the effect estimates were very small ( β for 5 nmol/L increment of maternal 25( OH) D = 0.10; [95% CI 0.00, 0.19]). Conclusion We observed very little indication that maternal or cord blood 25( OH) D are associated with cognitive development, achievement, and behaviour between 8 months and 7 years of age. [ABSTRACT FROM AUTHOR]

ObjectiveMajor depressive disorder (MDD) during pregnancy increases the risk of adverse maternal and infant outcomes. Maternal nutritional status may be a modifiable risk factor for antenatal depression. We evaluated the association between patterns in mid-pregnancy nutritional biomarkers and MDD.DesignProspective cohort study.SettingPittsburgh, Pennsylvania, USA.SubjectsWomen who enrolled at ≤20 weeks’ gestation and had a diagnosis of MDD made with the Structured Clinical Interview for DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition) at 20-, 30- and 36-week study visits. A total of 135 women contributed 345 person-visits. Non-fasting blood drawn at enrolment was assayed for red cell essential fatty acids, plasma folate, homocysteine and ascorbic acid; serum 25-hydroxyvitamin D, retinol, vitamin E, carotenoids, ferritin and soluble transferrin receptors. Nutritional biomarkers were entered into principal components analysis.ResultsThree factors emerged: Factor 1, Essential Fatty Acids; Factor 2, Micronutrients; and Factor 3, Carotenoids. MDD was prevalent in 21·5 % of women. In longitudinal multivariable logistic models, there was no association between the Essential Fatty Acids or Micronutrients pattern and MDD either before or after adjustment for employment, education or pre-pregnancy BMI. In unadjusted analysis, women with factor scores for Carotenoids in the middle and upper tertiles were 60 % less likely than women in the bottom tertile to have MDD during pregnancy, but after adjustment for confounders the associations were no longer statistically significant.ConclusionsWhile meaningful patterns were derived using nutritional biomarkers, significant associations with MDD were not observed in multivariable adjusted analyses. Larger, more diverse samples are needed to understand nutrition–depression relationships during pregnancy. [ABSTRACT FROM AUTHOR]

Vitamin D deficiency is highly prevalent worldwide, and is linked to several major chronic, inflammatory and autoimmune diseases. Vitamin D deficiency has not been evaluated in dark skinned individuals living in areas of high sun exposure utilizing more reliable mass spectrometry assay techniques. We determined the prevalence of 25-hydroxyvitamin D (25(OH)D) deficiency in Afro-Caribbean men on the tropical island of Tobago, where there is a high level of sunshine year round. Serum 25(OH)D2 and 25(OH)D3 metabolites were measured following extraction and purification using liquid chromatography and tandem mass spectrometry in 424 Afro-Caribbean men aged > 65 years from a larger population-based cohort study. The mean (+/- SD) serum total 25(OH)D concentration was 35.1 +/- 8.9 ng/mL. Deficiency (< 20 ng/mL) was present in only 2.8% and insufficiency (< 30 ng/mL) in 24% of the men. Multiple linear regression analysis identified age, BMI and daily vitamin D supplementation as the independent correlates of 25(OH)D. None of the men who consumed fish more than once per week had vitamin D deficiency, compared to 4% of the men who consumed fish once per week or less (P = .01, adjusted for age, BMI, and daily vitamin D supplementation). In conclusion, vitamin D deficiency is very uncommon in this Afro-Caribbean population. Longitudinal studies are needed to delineate the possible effects of high vitamin D levels in this population on major diseases hypothesized to be associated with vitamin D deficiency. [ABSTRACT FROM AUTHOR]

Objective: To assess the adequacy of periconceptional intake of key micronutrients for perinatal health in relation to regular cereal consumption of pregnant women. Design, setting and subjects: Low-income pregnant women (n 596) in Pittsburgh, Pennsylvania, USA, who enrolled in a cohort study at <20 weeks' gestation. These women reported usual dietary intake in the three months around conception on an FFQ. Cereal consumers were women who reported consuming any dry cereal at least three times per week. High risk for nutrient inadequacy was defined as intake less than the Estimated Average Requirement. Results: About 31% of the women regularly consumed cereal. After adjusting for energy intake, race/ethnicity, marital status, breakfast consumption and supplement use, cereal eaters had significantly higher intakes of folate, Fe, Zn, Ca, fibre and vitamins A, C, D and E (all P<0.01) and were approximately two to six times more likely to have intakes in the highest third of the distribution for folate, Fe, Zn, Ca, vitamins A and D, and fibre (all P<0.01) than cereal non-eaters. Cereal consumption was also associated with reductions of 65-90% in the risk of nutrient inadequacies compared with non-consumption (all P<0.01). Conclusions: Encouraging cereal consumption may be a simple, safe and inexpensive nutrition intervention that could optimize periconceptional intake for successful placental and fetal development. [ABSTRACT FROM AUTHOR]

Serum banks from large, decades-old epidemiological studies provide a valuable opportunity to explore the contributions of in utero vitamin D exposure to fetal origins of adult diseases. We compared 25-hydroxyvitamin D (25(OH)D) by race and season (two powerful predictors of vitamin D status) in sera frozen for ≥ 40 years with sera frozen for ≤ 2 years to determine whether 25(OH)D is stable enough to test vitamin D-related hypotheses. Data and sera came from seventy-nine pregnant women at 29–32 weeks' gestation in the Boston Collaborative Perinatal Project (CPP; 1959–66) and 124 women at 20–36 weeks' gestation in a 2003–2006 Pittsburgh cohort study. Multivariable linear regression models were used to test main and joint effects of race and season after confounder adjustment. In both cohorts, serum 25(OH)D levels were lower among black than white women (CPP 33·3 v. 46·7 nmol/l, P < 0·01; Pittsburgh 47·1 v. 89·6 nmol/l; P < 0·0001) and in winter than summer (CPP 32·7 v. 47·6 nmol/l, P < 0·0001; Pittsburgh 66·7 v. 89·8 nmol/l, P < 0·001), with no evidence of a race × season interaction in either cohort. Differences remained significant after confounder adjustment. When CPP and Pittsburgh results were compared, there was no significant difference in the race or season effects. The similarity in the relative change in 25(OH)D in these cohorts by two powerful predictors of vitamin D status suggests that, even if 25(OH)D deteriorated somewhat, it did so similarly across samples. Therefore, trends could be obtained from the decades-old serum data that would be relevant in exploring vitamin D-related hypotheses in future studies. [ABSTRACT FROM PUBLISHER]

The article discusses a study which examined the relationship between incident obesity and stillbirth. The study involved women who became obese prior to a subsequent pregnancy. It analyzed the relationship between internal validity and external validity and the effect of pre-pregnancy obesity on the outcome of pregnancy.

An increasing number of recent studies have suggested that doubly robust estimators with cross-fitting should be used when estimating causal effects with machine learning methods. However, not all existing programs that implement doubly robust estimators support machine learning methods and cross-fitting, or provide estimates on multiplicative scales. To address these needs, we developed AIPW , a software package implementing augmented inverse probability weighting (AIPW) estimation of average causal effects in R (R Foundation for Statistical Computing, Vienna, Austria). Key features of the AIPW package include cross-fitting and flexible covariate adjustment for observational studies and randomized controlled trials (RCTs). In this paper, we use a simulated RCT to illustrate implementation of the AIPW estimator. We also perform a simulation study to evaluate the performance of the AIPW package compared with other doubly robust implementations, including CausalGAM , npcausal , tmle , and tmle3. Our simulation showed that the AIPW package yields performance comparable to that of other programs. Furthermore, we also found that cross-fitting substantively decreases the bias and improves the confidence interval coverage for doubly robust estimators fitted with machine learning algorithms. Our findings suggest that the AIPW package can be a useful tool for estimating average causal effects with machine learning methods in RCTs and observational studies. [ABSTRACT FROM AUTHOR]

A response from the author of the article regarding the influence of access to palliative care programs to decision-making after a major fetal anomaly diagnosis is presented.

Background: Life course factors may be associated with pre-pregnancy body mass index and gestational weight gain; however, collecting information on pre-pregnancy exposures and pregnancy health in the same cohort is challenging. Objectives: The Life-course Experiences And Pregnancy (LEAP) study aims to identify adolescent and young adult risk factors for pre-pregnancy weight and gestational weight gain (GWG). We built upon an existing cohort study to overcome challenges inherent to studying life course determinants of pregnancy health. Population: Participants in an ongoing prospective cohort study of weight-related health who identified as women. Design: Retrospective cohort study. Methods: In 2019–2020, 1,252 women participating since adolescence in a cohort study of weight-related health were invited to complete an online reproductive history survey. Participants who reported a live birth were invited to release their prenatal, delivery, and postpartum medical records for validation of survey reports. Descriptive analyses were conducted to assess the characteristics of the overall cohort and the medical record validation subsample, and to describe adolescent and young adult characteristics of those with high (>80th percentile), moderate (20th-80th percentile), and low (<20th percentile) GWG z-score for gestational age and pre-pregnancy weight status. Preliminary results: Nine hundred seventy-seven women (78%) completed the LEAP survey and 656 reported a live birth. Of these, 379 (58%) agreed to release medical records, and 250 records were abstracted (66% of the 379). Of the 977 survey respondents 769 (79%) reported attempting a pregnancy, and 656 (67%) reported at least one live birth. The validation subsample was similar to the overall cohort. Women with a high GWG had a higher adolescent BMI percentile and prevalence of unhealthy weight control behaviors than those with moderate or low GWG. Conclusions: LEAP offers a valuable resource for identifying life course factors that may influence the health of pregnant people and their offspring. [ABSTRACT FROM AUTHOR]