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Background Most studies of folate metabolism and reproduction have been conducted after pregnancy and in folate-deficient populations. However, measurement of maternal folate status preconceptionally may be most relevant to certain folate-linked early processes preceding a successful pregnancy, and there has been a major increase in folate concentrations in women of childbearing age in high resource settings. Objective To examine associations between preconceptional biomarkers of maternal folate status (folate and homocysteine) and reproductive outcomes in folate-replete women. Study Design Cohort nested within the Effects of Aspirin in Gestation and Reproduction trial, a block-randomized, double-blind, placebo-controlled trial whereby women were randomized to daily low-dose aspirin (81 mg/day) or placebo and all women received folic acid (400 μg/day). In total, 1228 women with 1–2 previous pregnancy losses and no documented infertility were recruited from 4 clinical sites in the United States (2006–2012) and were attempting pregnancy for up to 6 menstrual cycles. Log-binomial regression models were used to estimate relative risks and 95% confidence intervals between preconception serum folate and plasma homocysteine for anovulation, pregnancy, and pregnancy loss. Results Greater plasma homocysteine was nonlinearly associated with greater risks of pregnancy loss only among women with 2 previous losses: a relative risk of 1.43 (95% confidence interval, 1.08–1.89) was found for plasma homocysteine concentrations at the study median of 8.0 μmol/L compared with a US population median of 6.0 μmol/L. No meaningful relationships were found between serum folate and any reproductive outcome or between plasma homocysteine and anovulation or becoming pregnant. Conclusion These data justify further study of the role of folate and homocysteine metabolism in normal and abnormal early pregnancy.

OBJECTIVES: The association between caffeine and pregnancy loss remains controversial due to limitations of prior studies such as relying on self-reported intake only, exposure measurement after clinical confirmation of pregnancy, and potential time-varying confounding by nausea/vomiting and lifestyle factors, which may be affected by prior caffeine exposure. Thus, our aim was to evaluate associations of preconception and early pregnancy serum caffeine, paraxanthine, and theobromine, self-reported intake of caffeinated beverages, and risk of pregnancy loss among 1228 reproductive-age women attempting pregnancy in the EAGeR trial during 2007–2011. METHODS: We estimated HRs and 95% CIs for any pregnancy loss, hCG loss (prior to ultrasound confirmation), and clinical loss (after ultrasound confirmation) according to caffeinated beverage intake and caffeine biomarkers measured at preconception and the 8(th) week of gestation using weighted adjusted Cox proportional hazards models. RESULTS: At preconception, 67%, 28%, and 9% of women reported any intake of caffeinated sodas, coffee, and tea, respectively. Preconception total caffeinated beverage intake of ≥3 vs. 0 cups/day was associated with 85% (95% CI: 1.18, 2.94) higher risk of any pregnancy loss, driven primarily by associations for hCG loss (HR: 2.88 (95% CI: 1.20, 6.91)). Caffeinated soda intake was associated with hCG loss (≥2 vs. 0.2 vs. ≤0.2 ng/mL) at preconception was strongly associated with hCG loss (HR: 4.51 (95% CI: 1.36, 14.91)). Serum caffeine, paraxanthine, and theobromine measured at the 8th week of gestation were not associated with risk of loss. CONCLUSIONS: Collectively, these data suggest that caffeine intake prior to pregnancy may increase risk of pregnancy loss, particularly in early gestation. FUNDING SOURCES: Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD.

OBJECTIVES: Experimental data indicate that maternal exposure to factors known to alter inflammatory milieu may be specifically harmful to the conception or survival of male fetuses. Indeed, in a recent clinical trial, preconception administration of low dose aspirin versus placebo restored the skewed sex ratio at birth among women with elevated inflammation, providing direct evidence of this phenomenon in humans. However, it is unknown whether other factors associated with inflammation, such as vitamin D status, are associated with offspring sex ratio at birth. Our objective was thus to evaluate the association of preconception serum 25-hydroxyvitamin D levels [25(OH)D] and male live birth among 1228 reproductive-age women with a history of 1–2 prior losses who were enrolled in the Effects of Aspirin in Gestation and Reproduction trial between 2007–2011. METHODS: We estimated RRs and 95% CIs for male live birth according to 25(OH)D sufficiency (≥75 vs. 1.95 ng/mL: RR: 1.41; 95% CI: 0.99, 2.00 versus ≤1.95 ng/mL RR: 1.11; 95% CI: 0.88, 1.41), a marker of systemic low-grade inflammation. CONCLUSIONS: Preconception vitamin D status was associated with male live birth, particularly among women with low-grade inflammation. These data suggest that maternal vitamin D sufficiency may mitigate maternal inflammation that would otherwise be detrimental to male fetal survival. FUNDING SOURCES: Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD.

Objective To assess the association of total isoflavone intake with ovulatory function, including sporadic anovulation in healthy premenopausal women. Design Prospective cohort study. Setting University. Patient(s) Participants included 259 healthy regularly menstruating women aged 18–44 years. Intervention(s) None. Main Outcome Measure(s) Serum concentrations of E 2 , free E 2 , P, LH, FSH, and SHBG and sporadic anovulation in healthy premenopausal women. Result(s) Isoflavone intake was not associated with E 2 , free E 2 , P, LH, and FSH concentrations. Consumption in the highest quartile (Q4: 1.6–78.8 mg/d) was significantly associated with greater SHBG concentrations (β = 0.09; 95% confidence interval [CI] 0.02–0.16), compared with the first quartile (Q1: 0.0–0.3 mg/d). Conclusion(s) Isoflavone intake was not associated with sporadic anovulation (Q4 vs. Q1: odds ratio 0.87, 95% CI 0.32–1.66). Dietary isoflavone intake among young premenopausal women was not related to sex hormone concentrations or anovulation, but was associated with minimally increased SHBG concentrations. These results suggest potential endocrine effects with no subsequent effects on ovulation, easing concerns regarding their impacts on fertility.

Background Low-dose aspirin (LDA) has been proposed to improve pregnancy outcomes in couples experiencing recurrent pregnancy loss. However, results from studies of LDA on pregnancy outcomes have been inconsistent, perhaps because most studies evaluated LDA-initiated post-conception. The purpose of the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial was to determine whether preconception-initiated LDA improves livebirth rates in women with one to two prior losses. Methods We performed a multicentre, block randomised, double-blind, placebo-controlled trial. Study participants were recruited using community-based advertisements and physician referral to four university medical centres in the US (2006–12). Eligible women were aged 18–40 years actively trying to conceive, with one to two prior losses. Participants were randomised to receive daily LDA (81 mg/day) or a matching placebo, and all were provided with daily 400-mcg folic acid. Follow-up continued for ≤6 menstrual cycles while attempting to conceive. For those who conceived, treatment was continued until 36 weeks gestation. The primary outcome was the cumulative livebirth rate over the trial period. Results There were 1228 women randomised (615 LDA, 613 placebo). Participants had a mean age of 28.7, were mostly white (95%), well educated (86% more than high school education), and employed (75%) with a household income >$100 000 annually (40%). The characteristics of those in the treatment and placebo arms were well balanced. Conclusions We describe the study design, recruitment, data collection, and baseline characteristics of participants enrolled in EAGeR, which aimed to determine the effect of LDA on livebirth and other pregnancy outcomes in these women.

Biomarker assessment plays a critical role in the study and prevention of disease. However, variation in biomarkers attributable to the menstrual cycle in premenopausal women may impair understanding the role of certain biomarkers in disease development and progression. Thus, in light of the recently increasing evidence of menstrual cycle variability in multiple cardiometabolic biomarkers, a reexamination of approaches for appropriately studying and diagnosing cardiovascular disease in premenopausal women is warranted. We reviewed studies (from 1934 through 2012) evaluating changes in cardiometabolic biomarkers across phases of the menstrual cycle, including markers of oxidative stress, lipids, insulin sensitivity, and systemic inflammation. Each was observed to vary significantly during the menstrual cycle. For example, nearly twice as many women had elevated cholesterol levels warranting therapy (≥200 mg/dL) during the follicular phase compared with the luteal phase (14.3% vs. 7.9%), with only 3% having consistently high levels during all phases of the cycle. Similarly, nearly twice as many women were classified as being at an elevated risk of cardiovascular disease (high sensitivity C-reactive protein >3 mg/L) during menses compared with other phases (12.3% vs. 7.4%). Menstrual cycle–associated variability in cardiometabolic biomarkers is an important source of variability that should be accounted for in both research and clinical settings.

Objective. The aim of this study was to investigate how serum retinol and carotenoids (β-carotene, β-cryptoxanthin, lutein/zeaxanthin, lycopene) are associated with biomarkers of insulin resistance. Research Methods and Procedures. The BioCycle Study (2005–2007) is a prospective cohort of 259 healthy premenopausal women. Fasting serum samples were collected at up to sixteen clinic visits, from which retinol, carotenoids, insulin, glucose, and sex hormone-binding globulin (SHBG) were measured. Insulin resistance was estimated by the homeostasis model assessment (HOMA-IR). Linear mixed models were used to determine associations adjusting for age, race, body mass index (BMI), education, smoking, physical activity, triglycerides, and energy intake. Results. Retinol was positively associated with HOMA-IR (β=0.19 (95% CI: 0.07, 0.32)) units per ug/mL increase in retinol; the relationship was driven by insulin (β=0.20 (95% CI: 0.08, 0.31)). Retinol was inversely associated with SHBG (β=−0.22 (95% CI: −0.28, −0.16)). Although no significant associations were found between serum carotenoids and HOMA-IR, β-carotene was positively associated with SHBG and β-cryptoxanthin inversely with fasting plasma glucose. Conclusion. Results indicate a possible role for serum retinol in the pathogenesis of type 2 diabetes. However, they do not support a strong association between individual or total serum carotenoids and insulin resistance.

Gestational diabetes mellitus (GDM), a common pregnancy complication, affects approximately 7–14% of pregnancies in high-risk populations,1 and as high as 18% according to recent recommendations from the International Association of Diabetes and Pregnancy Study Groups.2 Over the past several years, the prevalence of GDM has been increasing.3,4 A pregnancy complicated by GDM is at risk for further complications, such as preeclampsia, and GDM is related to elevated future risk of type 2 diabetes and cardiovascular diseases1 after pregnancy. Outside of pregnancy, clinical depression has been associated with an increased risk for type 2 diabetes,5,6 with evidence for a bidirectional relationship.7 While few studies have evaluated the association between diabetes and the onset of perinatal depression,8,9 and there is some evidence that treating GDM reduces the risk for postpartum depression,10 it is unknown whether a history of depression is associated with an increased risk of GDM during pregnancy. Both behavioural and biological theories exist to support the potential association between depression and GDM. Depression and depressive symptoms are associated with obesity and behaviours related to the development of type 2 diabetes and GDM, such as excessive caloric intake, physical inactivity and smoking.11 There are also hypotheses that describe an underlying biological association between depression and diabetes. Depression can cause activation of the hypothalamic-pituitary-adrenal (HPA) axis, leading to enhanced and sustained cortisol secretion. Cortisol opposes the action of insulin, and can lead to visceral adiposity, insulin resistance and other risk precursors of diabetes.11 Since depression is common among women of reproductive age,12 it could represent an important and prevalent risk factor for targeted GDM prevention. We have, therefore, evaluated the association between a medical history of depression and GDM in the Consortium on Safe Labor (CSL), a large, multi-ethnic cohort representative of the US population.

Do ovulatory hormone profiles among healthy premenopausal women differ between women with and without sporadic anovulation?Women with one anovulatory cycle tended to have lower estradiol, progesterone and LH peak levels during their ovulatory cycle.Anovulation occurs sporadically in healthy premenopausal women, but the influence of hormones in a preceding cycle and the impact on a subsequent cycle's hormone levels is unknown.The BioCycle Study was a prospective cohort including 250 healthy regularly menstruating women, 18-44 years of age, from Western New York with no history of menstrual or ovulation disorders. The women were followed with up to eight study visits per cycle for two cycles, most of which were consecutive.All study visits were timed to menstrual cycle phase using fertility monitors and located at the University at Buffalo women's health research center from 2005 to 2007. The main outcomes measured were estradiol, progesterone, LH and follicle-stimulating hormone levels in serum at up to 16 visits over two cycles. Anovulation was defined as peak serum progesterone concentrations ≤5 ng/ml and no serum LH peak detected during the mid- or late-luteal phase visit.Reproductive hormone concentrations were lower during anovulatory cycles, but significant reductions were also observed in estradiol (-25%, P = 0.003) and progesterone (-22%, P = 0.001) during the ovulatory cycles of women with one anovulatory cycle compared with women with two ovulatory cycles. LH peak concentrations were decreased in the ovulatory cycle of women with an anovulatory cycle (significant amplitude effect, P = 0.004; geometric mean levels 38% lower, P0.05).Follow-up was limited to two menstrual cycles, and no ultrasound assessment of ovulation was available. Data were missing for a total of 168 of a possible 4072 cycle visits (4.1%), though all women had at least five visits per cycle (94% had seven or more per cycle).These results suggest a possible underlying cause of anovulation, such as a longer-term subclinical follicular, ovarian or hypothalamic/pituitary dysfunction, even among healthy, regularly menstruating women.

Exposure to metals, specifically cadmium, lead, and mercury, is widespread and is associated with reduced bone mineral density (BMD) in older populations, but the associations among premenopausal women are unclear. Therefore, we evaluated the relationship between these metals in blood and BMD (whole body, total hip, lumbar spine, and non-dominant wrist) quantified by dual energy x-ray absorptiometry in 248 premenopausal women, aged 18–44. Participants were of normal body mass index (mean BMI 24.1), young (mean age 27.4), 60% were white, 20% non-Hispanic black, 15% Asian, and 6% other race group, and were from the Buffalo, New York region. The median (interquartile range) level of cadmium was 0.30 μg/l (0.19–0.43), of lead was 0.86 μg/dl (0.68–1.20), and of mercury was, 1.10 μg/l (0.58–2.00). BMD was treated both as a continuous variable in linear regression and dichotomized at the 10th percentile for logistic regression analyses. Mercury was associated with reduced odds of decreased lumbar spine BMD (0.66, 95% confidence interval: 0.44, 0.99), but overall, metals at environmentally relevant levels of exposure were not associated with reduced BMD in this population of healthy, reproductive-aged women. Further research is needed to determine if the blood levels of cadmium, lead, and mercury in this population are sufficiently low that there is no substantive impact on bone, or if effects on bone can be expected only at older ages.

STUDY QUESTION Are maternal preconception lipid levels associated with fecundability? SUMMARY ANSWER Fecundability was reduced for all abnormal female lipid levels including total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and total triglyceride levels. WHAT IS KNOWN ALREADY Subfecundity affects 7-15% of the population and lipid disorders are hypothesized to play a role since cholesterol acts as a substrate for the synthesis of steroid hormones. Evidence illustrating this relationship at the mechanistic level is mounting but few studies in humans have explored the role of preconception lipids in fecundity. STUDY DESIGN, SIZE, DURATION A secondary analysis of the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial (2007-2011), a block-randomized, double-blind, placebo-controlled trial. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 1228 women, with 1-2 prior pregnancy losses and without a diagnosis of infertility, attempting pregnancy for up to six menstrual cycles were recruited from clinical sites in Utah, New York, PA and Colorado. Time to pregnancy was the number of menstrual cycles to pregnancy as determined by positive hCG test or ultrasound. Individual preconception lipoproteins were measured at baseline, prior to treatment randomization and dichotomized based on clinically accepted cut-points as total cholesterol ≥200 mg/dl, LDL-C ≥130 mg/dl, HDL-C

Importance Nausea and vomiting during pregnancy have been associated with a reduced risk for pregnancy loss. However, most prior studies enrolled women with clinically recognized pregnancies, thereby missing early losses. Objective To examine the association of nausea and vomiting during pregnancy with pregnancy loss. Design, Setting, and Participants A randomized clinical trial, Effects of Aspirin in Gestation and Reproduction, enrolled women with 1 or 2 prior pregnancy losses at 4 US clinical centers from June 15, 2007, to July 15, 2011. This secondary analysis was limited to women with a pregnancy confirmed by positive results of a human chorionic gonadotropin (hCG) test. Nausea symptoms were ascertained from daily preconception and pregnancy diaries for gestational weeks 2 to 8. From weeks 12 to 36, participants completed monthly questionnaires summarizing symptoms for the preceding 4 weeks. A week-level variable included nausea only, nausea with vomiting, or neither. Main Outcomes and Measures Peri-implantation (hCG-detected pregnancy without ultrasonographic evidence) and clinically recognized pregnancy losses. Results A total of 797 women (mean [SD] age, 28.7 [4.6] years) had an hCG-confirmed pregnancy. Of these, 188 pregnancies (23.6%) ended in loss. At gestational week 2, 73 of 409 women (17.8%) reported nausea without vomiting and 11 of 409 women (2.7%), nausea with vomiting. By week 8, the proportions increased to 254 of 443 women (57.3%) and 118 of 443 women (26.6%), respectively. Hazard ratios (HRs) for nausea (0.50; 95% CI, 0.32-0.80) and nausea with vomiting (0.25; 95% CI, 0.12-0.51) were inversely associated with pregnancy loss. The associations of nausea (HR, 0.59; 95% CI, 0.29-1.20) and nausea with vomiting (HR, 0.51; 95% CI, 0.11-2.25) were similar for peri-implantation losses but were not statistically significant. Nausea (HR, 0.44; 95% CI, 0.26-0.74) and nausea with vomiting (HR, 0.20; 95% CI, 0.09-0.44) were associated with a reduced risk for clinical pregnancy loss. Conclusions and Relevance Among women with 1 or 2 prior pregnancy losses, nausea and vomiting were common very early in pregnancy and were associated with a reduced risk for pregnancy loss. These findings overcome prior analytic and design limitations and represent the most definitive data available to date indicating the protective association of nausea and vomiting in early pregnancy and the risk for pregnancy loss. Trial Registration clinicaltrials.gov Identifier:NCT00467363

Background: Dairy food intake has been associated with infertility; however, little is known with regard to associations with reproductive hormones or anovulation. Objective: We investigated whether intakes of dairy foods and specific nutrients were associated with reproductive hormone concentrations across the cycle and the risk of sporadic anovulation among healthy women. Methods: We prospectively measured serum reproductive hormones ≤8 times/menstrual cycle for 2 cycles from 259 regularly menstruating women (mean age: 27.3 y). Dairy food intake was assessed via 24-h dietary recalls 4 times/cycle. Dairy food intakes were assessed by 1) total and low- and high-fat dairy products; 2) dairy nutrients, including fat, lactose, calcium, and phosphorus; and 3) dairy foods, including milk, cheese, butter, cream, yogurt, and ice cream categories. Weighted linear mixed models were used to evaluate associations between dairy nutrients or food intakes and hormone concentrations. Modified Poisson regression models with robust error variance were used to evaluate anovulation. Models were adjusted for age, body mass index, race, physical activity, Mediterranean diet score, total energy, protein, fiber, caffeine, and other hormones. Results: Each serving increase in total and low- and high-fat dairy foods and all increases in amounts of all dairy nutrients tested were associated with an ∼5% reduction in serum estradiol concentrations but were not associated with anovulation. Total and high-fat dairy food intakes were positively associated with serum luteinizing hormone concentrations. We observed associations between intakes of >0 servings of yogurt (RR: 2.1; 95% CI: 1.2, 3.7) and cream (RR: 1.8; 95% CI: 1.0, 3.2) and a higher risk of sporadic anovulation compared with no intake. Conclusions: Our study showed associations between increasing dairy food and nutrient intakes and decreasing estradiol concentrations as well as between cream and yogurt intakes and the risk of sporadic anovulation. These results highlight the potential role of dairy in reproductive function in healthy women.

Context: Inflammation is linked to causes of infertility. Low-dose aspirin (LDA) may improve reproductive success in women with chronic, low-grade inflammation. Objective: To investigate the effect of preconception-initiated LDA on pregnancy rate, pregnancy loss, live birth rate, and inflammation during pregnancy. Design: Stratified secondary analysis of a multicenter, block-randomized, double-blind, placebo-controlled trial. Setting: Four US academic medical centers, 2007 to 2012. Participants: Healthy women aged 18 to 40 years (N = 1228) with one to two prior pregnancy losses actively attempting to conceive. Intervention: Preconception-initiated, daily LDA (81 mg) or matching placebo taken up to six menstrual cycles attempting pregnancy and through 36 weeks’ gestation in women who conceived. Main Outcome Measures: Confirmed pregnancy, live birth, and pregnancy loss were compared between LDA and placebo, stratified by tertile of preconception, preintervention serum high-sensitivity C-reactive protein (hsCRP) (low, Preconception-initiated low-dose aspirin improved pregnancy and live birth rates among women with low-grade inflammation prior to pregnancy.

Background: Phytoestrogens have been associated with subtle hormonal changes, but their effects on endometriosis are largely unknown. Objective: We assessed the association between urinary concentrations of phytoestrogens and incident endometriosis. Methods: We included an operative sample of 495 premenopausal women aged 18–44 y undergoing laparoscopies and laparotomies at 14 clinical sites between 2007 and 2009 and a general population sample of 131 women from the same geographic area who were matched on age and menstruation status. Endometriosis in the surgical sample was assessed by surgical visualization (clinical gold standard), whereas disease in the general population sample was assessed with the use of a pelvic MRI. Urine concentrations of genistein, daidzen, O-desmethylangolensin, equol, enterodiol, and enterolactone were measured at baseline. Poisson regression with robust error variance was used to estimate the risk of an endometriosis diagnosis for each sample after adjusting for age and body mass index (in kg/m2). Separate models were run for each phytoestrogen. Results: Overall geometric mean urine concentrations of phytoestrogens were as follows: genistein [88 nmol/L (95% CI: 72, 108 nmol/L)], daidzein [194 nmol/L (95% CI: 160, 236 nmol/L)], O-desmethylangolensin [4 nmol/L (95% CI: 3, 6 nmol/L)], equol [4 nmol/L (95% CI: 4, 6 nmol/L)], enterodiol [29 nmol/L (95% CI: 22, 38 nmol/L)], and enterolactone [355 nmol/L (95% CI: 395, 544 nmol/L)]. Geometric mean concentrations of phytoestrogens did not significantly differ by endometriosis status in either sample. Adjusted RRs for endometriosis ranged from 0.87 to 1.09 for the 6 phytoestrogens measured, with all CIs including a value ≥1. Phytoestrogens were not associated with the severity of endometriosis when restricting the analysis to women with moderate-to-severe disease per the revised American Society for Reproductive Medicine criteria. Furthermore, no associations were observed between self-reported high soy intake and endometriosis. Conclusions: Despite endometriosis being an estrogen-dependent disease, we found no evidence that urinary phytoestrogens were associated with a higher risk of an endometriosis diagnosis in either a sample of premenopausal women or in a surgical sample.

To evaluate complications and safety of preconception low-dose aspirin in 1,228 U.S. women (2007-2011).Evaluation of the safety of low-dose aspirin in the participants and their fetuses was a planned secondary analysis of the Effects of Aspirin in Gestation and Reproduction trial, a multicenter, block-randomized, double-blind, placebo-controlled trial investigating the effect of low-dose aspirin on the incidence of live birth. Women aged 18-40 years with a history of one to two pregnancy losses trying to conceive were randomized to daily low-dose aspirin (81 mg, n=615) or placebo (n=613) and were followed for up to six menstrual cycles or through gestation if they became pregnant. Emergency care visits and possible aspirin-related symptoms were assessed at each study follow-up using standardized safety interviews. In addition, complications for both the participant and her fetus or neonate were captured prospectively using case report forms, interviews conducted during pregnancy and postpartum, and medical records.The proportion of women with at least one possible aspirin-related symptom during the trial was similar between treatment arms (456 [74%] low-dose aspirin compared with 447 [73%] placebo, P=.65) as was the proportion with at least one emergency care visit (104 [17%] low-dose aspirin compared with 99 [16%] placebo, P=.76). Maternal complications were evenly distributed by treatment arm with the exception of vaginal bleeding, which was more commonly reported in the low-dose aspirin arm (22% compared with 17%, P=.02). The distribution of fetal and neonatal complications-which included three stillbirths, three neonatal deaths, and 10 neonates with birth defect(s)-was similar between treatment arms.Although rare but serious complications resulting from low-dose aspirin cannot be ruled out, preconception low-dose aspirin appears to be well tolerated by women trying to conceive, women who become pregnant, and by their fetuses and neonates.

Background Human exposure to phenols and parabens is widespread. Within-person variability of urinary concentrations in healthy women is not well characterized. Objectives To characterize the variability of urinary phenol and paraben concentrations across two months and evaluate the ability of a single spot urine sample to characterize exposure. Methods 143 women provided 509 spot urine samples collected across two months of study (3–5 samples/woman). We measured urinary concentrations of 8 phenols: bisphenol A (BPA), benzophenone-3 (BP-3), benzophenone-1 (BP-1), 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), 2,4,5-trichlorophenol (2,4,5-TCP), 2,4,6-trichlorophenol (2,4,6-TCP), triclosan (TCS); and 8 parabens and their metabolites (benzyl (BzP), butyl (BuP), ethyl (EtP), heptyl (HeP), methyl (MeP), propyl (PrP), 4-hydroxybenzoic acid (4-HB), 3,4-dihydroxybenzoic acid (3,4-DHB)). Biomarker variability was characterized using the intraclass correlation coefficient (ICC) and surrogate category analyses were conducted. Results ICCs ranged from very low for BPA (0.04) to moderate for BP-3, BP-1, TCS, BzP, and MeP (0.66, 0.58, 0.55, 0.54, and 0.62, respectively). Surrogate analyses suggested that BP-1, BP-3, TCS, 2,4-DCP, BuP, and PrP may be characterized by a single spot sample (sensitivity range 0.76–0.86) but that additional samples were necessary for BPA, HeP, 4-HB, and 3,4-DHB (sensitivity range 0.47–0.61). Conclusions Urinary phenol and paraben metabolite concentrations were variable across two months in healthy women but the degree of reliability differed by the specific biomarker. A small number of samples may sufficiently characterize typical concentrations for BP-3, BP-1, TCS, BuP, and PrP; but additional biospecimens may be necessary to characterize exposure for other compounds, including BPA.

OBJECTIVE:To compare time to pregnancy and live birth among couples with varying intervals of pregnancy loss date to subsequent trying to conceive date.METHODS:In this secondary analysis of the Effects of Aspirin in Gestation and Reproduction trial, 1,083 women aged 18–40 years with one to two prior

STUDY QUESTION What is the association between daily preconception-initiated low-dose aspirin (LDA) treatment and very early pregnancy losses or euploid (chromosomally normal) losses among women with one to two prior losses? SUMMARY ANSWER Daily LDA initiated preconception was not associated with the rate or type of pregnancy loss among women with a history of one to two prior pregnancy losses. WHAT IS KNOWN ALREADY LDA is often used to treat recurrent pregnancy loss with reductions in pregnancy loss generally only observed among women with antiphospholipid antibodies, and null associations observed among women without antiphospholipid antibodies. We previously evaluated the association between LDA and pregnancy loss overall among women with one to two prior losses in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial and found no association, though did not distinguish between potential effects at different stages of pregnancy loss, including implantation failure, or between euploid and aneuploid losses. STUDY DESIGN, SIZE, DURATION The EAGeR trial was a multi-site prospective block-randomized double-blind placebo-controlled trial. In total, 1228 women were randomized to daily LDA (81 mg/day) plus folic acid (400 mcg/day), or placebo plus folic acid. Participants were assigned study drug for less than or equal to six menstrual cycles or if they conceived, throughout pregnancy with study drug discontinued at 36 weeks gestation. This analysis includes additional outcome information obtained from chart abstractions after the completion of the trial, as well as testing of stored urine for measurement of hCG and detection of very early pregnancy losses, and karyotyping of the products of conception for assessment of aneuploidy of the losses. PARTICIPANTS, SETTING, METHODS Women aged 18-40 with a history of one to two prior losses and actively trying to conceive were randomized (n = 615 LDA and n = 613 placebo) at four clinical centers in the USA (2007-2011). Log-binomial regression was used to estimate risk ratios under the intent-to-treat approach. MAIN RESULTS AND THE ROLE OF CHANCE Daily LDA initiated preconception was not associated with clinically recognized pregnancy losses or implantation failures among women with proved fecundity and a history of one to two prior losses. Specifically, 1088 (88.6%) women completed the trial with 797 having an hCG detected pregnancy (64.9%). Overall there were 133 clinical losses (12.7% LDA versus 11.8% placebo, P = 0.71) and 55 implantation failures (5.2% LDA versus 4.9% placebo, P = 0.89). No differences were found in rate of euploid losses (RR 1.11, 95% confidence interval: 0.99, 1.26). LIMITATIONS, REASONS FOR CAUTION Generalizability of these findings is limited to women with a history of one to two prior losses, and may further be limited to women of white race with higher socioeconomic status as given the rigors of the study protocol participants tended to be white and have higher incomes and more education. We were also missing karyotype information on approximately one-third of the clinically recognized pregnancy losses, which may limit our power to detect effects on euploid losses, though detailed sensitivity analysis showed similar results. WIDER IMPLICATIONS OF THE FINDINGS Our data do not support the general use of LDA to decrease pregnancy loss and further demonstrate no increased risk of loss for women on LDA treatment. STUDY FUNDING/COMPETING INTERESTS This research was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (Contract Nos. HHSN267200603423, HHSN267200603424, HHSN267200603426). The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER The trial was registered at ClinicalTrials.gov #NCT00467363. TRIAL REGISTRATION DATE 27 April 2007. DATE OF FIRST PATIENT'S ENROLLMENT 15 June 2007.

Anti-Müllerian hormone (AMH) reduces aromatase activity and sensitivity of follicles to FSH stimulation. Therefore, elevated serum AMH may indicate a higher threshold for response to ovulation induction in women with polycystic ovary syndrome (PCOS). This study sought to determine the association between AMH levels and ovulatory response to treatment among the women enrolled into the Pregnancy in PCOS II (PPCOS II) trial. This was a secondary analysis of data from a randomized clinical trial in academic health centers throughout the United States Participants: A total of 748 women age 18-40 years, with PCOS and measured AMH levels at baseline, were included in this study. Couples were followed for up to five treatment cycles to determine ovulation (midluteal serum progesterone > 5 ng/mL) and the dose required to achieve ovulation. A lower mean AMH and AMH per follicle was observed among women who ovulated compared with women who never achieved ovulation during the study (geometric mean AMH, 5.54 vs 7.35 ng/mL; P = .0001; geometric mean AMH per follicle, 0.14 vs 0.18; P = .01) after adjustment for age, body mass index, T, and insulin level. As AMH levels increased, the dose of ovulation induction medication needed to achieve ovulation also increased. No associations were observed between antral follicle count and ovulation. These results suggest that high serum AMH is associated with a reduced response to ovulation induction among women with PCOS. Women with higher AMH levels may require higher doses of medication to achieve ovulation.

C-reactive protein (CRP) is one of the most commonly used markers of acute phase reaction in clinical settings and predictors of cardiovascular risk in healthy women; however, data on its physiologic regulation in premenopausal women are sparse. The objective of this study was to evaluate the association between endogenous reproductive hormones and CRP in the BioCycle Study (2005–2007). Women aged 18–44 years from western New York were followed prospectively for up to 2 menstrual cycles (n = 259). Serum levels of CRP, estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone were measured up to 8 times per cycle, timed by fertility monitors. CRP levels varied significantly across the cycle (P < 0.001). More women were classified as being at elevated risk of cardiovascular disease (CRP, >3 mg/L) during menses compared with other phases (12.3% vs. 7.4%; P < 0.001). A 10-fold increase in estradiol was associated with a 24.3% decrease in CRP (95% confidence interval: 19.3, 29.0). A 10-fold increase in luteal progesterone was associated with a 19.4% increase in CRP (95% confidence interval: 8.4, 31.5). These results support the hypothesis that endogenous estradiol might have antiinflammatory effects and highlight the need for standardization of CRP measurement to menstrual cycle phase in reproductive-aged women.

Objective To investigate the influence of adiposity on patterns of sex hormones across the menstrual cycle among regularly menstruating women. Subjects The BioCycle Study followed 239 healthy women for 1–2 menstrual cycles, with up to 8 visits per cycle timed using fertility monitors. Methods Serum estradiol (E2), progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex hormone binding globulin (SHBG) were measured at each visit. Adiposity was measured by anthropometry and by dual energy x-ray absorptiometry. Differences in hormonal patterns by adiposity measures were estimated using nonlinear mixed models, which allow for comparisons in overall mean levels, amplitude (i.e. lowest to highest level within each cycle), and shifts in timing of peaks while adjusting for age, race, energy intake, and physical activity. Results Compared to normal weight women (n=154), obese women (BMI≥30 kg/m2, n=25) averaged lower levels of progesterone (−15%, P=0.003), LH (−17%, P=0.01), FSH (−23%, P=0.001) and higher free E2 (+22%, p=0.001) across the cycle. To lesser magnitudes, overweight women (BMI: 25–30, n=60) also exhibited differences in the same directions for mean levels of free E2, FSH, and LH. Obese women experienced greater changes in amplitude of LH (9%, p=0.002), and FSH (8%, p=0.004), but no differences were observed among overweight women. Higher central adiposity by top compared to bottom tertile of trunk-to-leg fat ratio by DXA was associated with lower total E2 (−14%, p=0.005) and FSH (−15%, p=0.001). Peaks in FSH and LH occurred later (~0.5 day) in the cycle among women with greater central adiposity. Conclusion Greater total and central adiposity were associated with changes in mean hormone levels. The greater amplitudes observed among obese women suggest compensatory mechanisms at work to maintain hormonal homeostasis. Central adiposity may be more important in influencing timing of hormonal peaks than total adiposity.

It is common practice in perinatal epidemiology to calculate gestational-age-specific or birth-weight-specific associations between an exposure and a perinatal outcome. Gestational age or birth weight, for example, might lie on a pathway from the exposure to the outcome. This practice of conditioning on a potential intermediate has come under critique for various reasons. First, if one is interested in assessing the overall effect of an exposure on an outcome, it is not necessary to stratify, and indeed it is important not to stratify, on an intermediate. Second, if one does condition on an intermediate, to try to obtain what might conceived of as a “direct effect” of the exposure on the outcome, then various biases and paradoxical results can arise. It is now well documented theoretically and empirically, that when there is an unmeasured common cause of the intermediate and the outcome, associations adjusted for the intermediate are subject to bias. In this paper we propose three approaches to facilitate valid inference when effects conditional on an intermediate are in view. These three approaches correspond to (i) conditioning on the predicted risk of the intermediate, (ii) conditioning on the intermediate itself in conjunction with sensitivity analysis, and (iii) conditioning on the subgroup of individuals for whom the intermediate would occur irrespective of the exposure received. The second and third approaches both require sensitivity analysis, and they result in a range of estimates. Each of the three approaches can be used to resolve the “birth-weight paradox” that exposures such as maternal smoking appear to have a protective effect among low-birth-weight infants. The various methodologic approaches described in this paper are applicable to a number of similar settings in perinatal epidemiology.

To evaluate whether the association between fiber intake and LH levels is driven by the association between fiber and estradiol, or whether there is an independent association.A prospective cohort of 259 premenopausal women were followed for up to 2 menstrual cycles. Estrogen and LH were measured ≤8 times per cycle at visits scheduled using fertility monitors. Diet was assessed ≤4 times per cycle by 24-h recall. Linear mixed models on the log scale of hormones were utilized to evaluate the total effects of fiber intake. Inverse probability weights were utilized to estimate the independent effect of fiber on LH levels.In unweighted analyses, we observed a significant, inverse association between fiber intake (in 5 g/day increments) and log LH levels (β, -0.051, 95% confidence interval (CI), -0.100, -0.002). No association was observed in the weighted analyses, after estradiol levels were taken into account (β, -0.016, 95% CI, -0.060, 0.027).The decreased levels of LH associated with high fiber intake were attenuated after taking estradiol levels into account, suggesting that the association between fiber and LH is most likely a consequence of fiber's impact on estradiol and not due to an independent mechanism.

Early age at menarche has been linked to an elevated risk of type 2 diabetes. However, the underlying mechanism is unclear.Our objective was to examine associations between age at menarche and type 2 diabetes risk factors.The BioCycle Study followed 253 healthy premenopausal women from the general population (Buffalo, NY) for one to two menstrual cycles.Age at menarche was self-reported. Body mass index and waist circumference were measured by trained personnel. Total body and trunk fat were measured by dual-energy x-ray absorptiometry. Fasting glucose, insulin, highly sensitive C-reactive protein, and SHBG levels were measured up to eight times per cycle. Insulin resistance (IR) and β-cell function were evaluated using the homeostasis model assessment (HOMA)-IR and HOMA-β.The mean age at menarche was 12.5 ± 1.2 yr. After adjustment for age, race, education, and physical activity, early menarche (≤12 yr) was significantly associated with an increase of 1.35 kg/m(2) in body mass index (P = 0.01), 2.52% in percent total body fat (P = 0.004), 3.02% in percent trunk fat (P = 0.004), 0.15 μIU/ml in (log)insulin (P = 0.02), 0.15 U in (log)HOMA-IR (P = 0.03), and 0.16 U in (log)HOMA-β (P = 0.01) compared with average menarche (12-14 yr). No associations were found for SHBG or highly sensitive C-reactive protein.Early onset of menarche is associated with unfavorable metabolic phenotypes compared with average onset of menarche in healthy premenopausal women, including reduced insulin sensitivity and β-cell function and greater total and trunk fat.

Background: Metals can interfere with hormonal functioning by binding at the receptor site and through indirect mechanisms; thus, they may be associated with hormonal changes in premenopausal women. Objectives: We examined the associations between cadmium, lead, and mercury, and anovulation and patterns of reproductive hormones [estradiol, progesterone, follicle-stimulating hormone (FSH), luteinizing hormone] among 252 premenopausal women 18–44 years of age who were enrolled in the BioCycle Study in Buffalo, New York. Methods: Women were followed for up to two menstrual cycles, with serum samples collected up to eight times per cycle. Metal concentrations were determined at baseline in whole blood by inductively coupled mass spectroscopy. Marginal structural models with stabilized inverse probability weights and nonlinear mixed models with harmonic terms were used to estimate the effects of cadmium, lead, and mercury on reproductive hormone levels during the menstrual cycle and anovulation. Results: Geometric mean (interquartile range) cadmium, lead, and mercury levels were 0.29 (0.19–0.43) μg/L, 0.93 (0.68–1.20) μg/dL, and 1.03 (0.58–2.10) μg/L, respectively. We observed decreases in mean FSH with increasing cadmium [second vs. first tertile: –10.0%; 95% confidence interval (CI), –17.3% to –2.5%; third vs. first tertile: –8.3%; 95% CI, –16.0% to 0.1%] and increases in mean progesterone with increasing lead level (second vs. first tertile: 7.5%; 95% CI, 0.1–15.4%; third vs. first tertile: 6.8%; 95% CI, –0.8% to 14.9%). Metals were not significantly associated with anovulation. Conclusions: Our findings support the hypothesis that environmentally relevant levels of metals are associated with modest changes in reproductive hormone levels in healthy, premenopausal women.

Summary Background Preconception-initiated low-dose aspirin might positively affect pregnancy outcomes, but this possibility has not been adequately assessed. Our aim was to investigate whether low-dose aspirin improved livebirth rates in women with one to two previous pregnancy losses. Methods In this multicentre, block-randomised, double-blind, placebo-controlled trial, women aged 18–40 years who were attempting to become pregnant were recruited from four medical centres in the USA. Participants were stratified by eligibility criteria—the original stratum was restricted to women with one loss at less than 20 weeks' gestation during the previous year, whereas the expanded stratum included women with one to two previous losses, with no restrictions on gestational age or time of loss. Women were block-randomised by centre and eligibility stratum in a 1:1 ratio. Preconception-initiated daily low-dose aspirin (81 mg per day) plus folic acid was compared with placebo plus folic acid for up to six menstrual cycles; for women who conceived, study treatment continued until 36 weeks' gestation. Participants, trial staff, and investigators were masked to the assigned treatment. The primary outcome was livebirth rate, which was analysed by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00467363. Findings Overall, 1228 women were recruited and randomly assigned between June 15, 2007, and July 15, 2011, 1078 of whom completed the trial and were included in the analysis (535 in the low-dose aspirin group and 543 in the placebo group). 309 (58%) women in the low-dose aspirin group had livebirths, compared with 286 (53%) in the placebo group (p=0·0984; absolute difference in livebirth rate 5·09% [95% CI −0·84 to 11·02]). Pregnancy loss occurred in 68 (13%) women in the low-dose aspirin group, compared with 65 (12%) women in the placebo group (p=0·7812). In the original stratum, 151 (62%) of 242 women in the low-dose aspirin group had livebirths, compared with 133 (53%) of 250 in the placebo group (p=0·0446; absolute difference in livebirth rate 9·20% [0·51 to 17·89]). In the expanded stratum, 158 (54%) of 293 women in the low-dose aspirin group and 153 (52%) of 293 in the placebo group had livebirths (p=0·7406; absolute difference in livebirth rate 1·71% [−6·37 to 9·79]). Major adverse events were similar between treatment groups. Low-dose aspirin was associated with increased vaginal bleeding, but this adverse event was not associated with pregnancy loss. Interpretation Preconception-initiated low-dose aspirin was not significantly associated with livebirth or pregnancy loss in women with one to two previous losses. However, higher livebirth rates were seen in women with a single documented loss at less than 20 weeks' gestation during the previous year. Low-dose aspirin is not recommended for the prevention of pregnancy loss. Funding Eunice Kennedy Shriver National Institute of Child Health and Human Development (US National Institutes of Health).

High-fiber diets are associated with improved lipid profiles. However, pre- and postmenopausal women respond differently to fiber intake, suggesting that endogenous estradiol mediates the effect. The authors' objective was to determine the direct effect of fiber intake on lipoprotein cholesterol levels independent of estradiol among premenopausal women. The BioCycle Study, a prospective cohort study conducted at the State University of New York at Buffalo from 2005 to 2007, followed 259 healthy women for up to 2 complete menstrual cycles. Serum lipoprotein and hormone levels were measured at 16 visits timed using fertility monitors. Fiber intake was assessed by 8 24-hour recalls. Marginal structural models with inverse probability weights for both lipoprotein and estradiol levels were used to estimate controlled direct effects of the highest category of fiber intake (≥22 g/day vs.

Context: Conflicting findings have been reported regarding the effect of menstrual cycle phase and sex hormones on insulin sensitivity. Objective: The aim was to determine the pattern of insulin resistance over the menstrual cycle and whether variations in sex hormones explain these patterns. Design: The BioCycle study is a longitudinal study that measured hormones at different phases of the menstrual cycle. Participants had up to eight visits per cycle; each visit was timed using fertility monitors to capture sensitive windows of hormonal changes. Setting: The study was conducted in the general community of the University at Buffalo (Buffalo, NY). Participants: A total of 257 healthy, premenopausal women (age, 27 ± 8 yr; body mass index, 24 ± 4 kg/m2) participated in the study. Main Outcome Measures: We measured fasting insulin, glucose, and insulin resistance by the homeostasis model of insulin resistance (HOMA-IR). Results: Significant changes in HOMA-IR were observed over the menstrual cycle; from a midfollicular phase level of 1.35, levels rose to 1.59 during the early luteal phase and decreased to 1.55 in the late-luteal phase. HOMA-IR levels primarily reflected changes in insulin and not glucose. After adjustment for age, race, cycle, and other sex hormones, HOMA-IR was positively associated with estradiol (β = 0.082; P < 0.001) and progesterone (β = 0.025; P < 0.001), and inversely associated with FSH (adjusted β = −0.040; P < 0.001) and SHBG (β = −0.085; P < 0.001). LH was not associated with HOMA-IR. Further adjustment for BMI weakened the association with SHBG (β = −0.057; P = 0.06) but did not affect other associations. Conclusion: Insulin exhibited minor menstrual cycle variability. Estradiol and progesterone were positively associated with insulin resistance and should be considered in studies of insulin resistance among premenopausal women.

Background: A Mediterranean diet has been associated with a reduced risk of cardiovascular disease and mortality. A possible mechanism is through a decrease in lipid peroxidation (LPO); however, evidence linking the Mediterranean diet with lower LPO in premenopausal women is sparse. Objective: We investigated whether adherence to a Mediterranean diet was associated with lower LPO concentrations in premenopausal women. Design: Two hundred fifty-nine healthy women aged 18–44 y were followed for ≤2 menstrual cycles. Plasma concentrations of F2-isoprostane (8-iso-PGF2α), 9-hydroxyoctadecadieneoic acid (9-HODE), and thiobarbituric acid reactive substances (TBARS) were measured ≤8 times per cycle at visits scheduled by using fertility monitors. Diet was assessed ≤4 times per cycle by using 24-h dietary recalls. The alternate Mediterranean Diet Score (aMED) (range: 0–9) was calculated on the basis of intake of vegetables, legumes, fruit, nuts, whole grains, red and processed meat, fish, and alcohol and the ratio of monounsaturated to saturated fat. Results: A 1-unit increase in aMED was associated with a 4.50% decrease in 8-iso-PGF2α concentrations (95% CI: −6.32%, −2.65%) and a 14.01% decrease in 9-HODE concentrations (95% CI: −17.88%, −9.96%) after adjustment for energy intake, age, race, body mass index, plasma ascorbic acid, and serum cholesterol. No significant association was observed between aMED and TBARS. A 1-unit increase in aMED was associated with a 1.39% increase (95% CI: 0.07%, 2.72%) in plasma ascorbic acid concentrations. Conclusions: Adherence to a Mediterranean diet is associated with lower LPO and higher ascorbic acid concentrations. These results confirm that decreased LPO is a plausible mechanism linking a Mediterranean diet to reduced cardiovascular disease risk.

Please cite this paper as: Zhang X, Mumford S, Cnattingius S, Schisterman E, Kramer M. Reduced birthweight in short or primiparous mothers: physiological or pathological?. BJOG 2010;117:1248–1254. Objective Customisation of birthweight-for-gestational-age standards for maternal characteristics assumes that variation in birth weight as a result of those characteristics is physiological, rather than pathological. Maternal height and parity are among the characteristics widely assumed to be physiological. Our objective was to test that assumption by using an association with perinatal mortality as evidence of a pathological effect. Design Population-based cohort study. Setting Sweden. Population A total of 952 630 singletons born at ≥28 weeks of gestation in the period 1992–2001. Methods We compared perinatal mortality among mothers of short stature (

Background Prior studies have reported mixed results regarding relationships between vitamin D, androgens, and sex hormone–binding globulin in patients with polycystic ovary syndrome. However, less is known regarding these associations in eumenorrheic, premenopausal women. Objective Our objective was to study the relationships between serum vitamin D and androgen biomarkers in eumenorrheic women with a history of pregnancy loss who were attempting pregnancy. Study Design This was an analysis of a cohort of 1191 participants from the Effects of Aspirin in Gestation and Reproduction trial (2006–2012). Participants were attempting to conceive, aged 18–40 years, with 1–2 documented prior pregnancy losses and no history of infertility, and recruited from 4 academic medical centers in the United States. Serum vitamin D (25-hydroxyvitamin D) and hormone concentrations were measured at baseline. Results Vitamin D concentration was negatively associated with free androgen index (percentage change [95% confidence interval, –5% (–8% to –2%)] per 10 ng/mL increase) and positively associated with sex hormone–binding globulin (95% confidence interval, 4% [2–7%]), although not with total testosterone, free testosterone, or dehydroepiandrosterone sulfate after adjusting for age, body mass index, smoking status, race, income, education, physical activity, and season of blood draw. Conclusion Overall, vitamin D was associated with sex hormone–binding globulin and free androgen index in eumenorrheic women with prior pregnancy loss, suggesting that vitamin D may play a role in the bioavailability of androgens in eumenorrheic women. We are limited in making assessments regarding directionality, given the cross-sectional nature of our study.

Cigarette smoking has been implicated in reproductive outcomes including delayed conception, but mechanisms underlying these associations remain unclear. One potential mechanism is the effect of cigarette smoking on reproductive hormones; however, studies evaluating associations between smoking and hormone levels are complicated by variability of hormones and timing of specimen collection. We evaluated smoking among women participating in the BioCycle Study, a longitudinal study of menstrual cycle function in healthy, premenopausal, regularly menstruating women (n = 259). Fertility monitors were used to help guide timing of specimen collection. Serum levels of oestradiol, progesterone, follicle-stimulating hormone (FSH), luteinising hormone (LH) and total sex-hormone binding globulin (SHBG) across phases of the menstrual cycle were compared between smokers and non-smokers. We observed statistically significant phase-specific differences in hormone levels between smokers and non-smokers. Compared with non-smokers, smokers had higher levels of FSH in the early follicular phase and higher LH at menses after adjusting for potential confounding factors of age, race, body mass index, parity, vigorous exercise, and alcohol and caffeine intake through inverse probability of treatment weights. No statistically significant differences were observed for oestradiol, progesterone or SHBG. These phase-specific differences in levels of LH and FSH in healthy, regularly menstruating women who are current smokers compared with non-smokers reflect one mechanism by which smoking may influence fertility and reproductive health.

To examine the longitudinal relation between perceived stress in the previous month and perimenstrual symptom severity across two cycles among regularly menstruating, healthy women (n = 259).At baseline (11 days before the first cycle), participants completed the 4-item Perceived Stress Scale (PSS) for the previous month (first cycle exposure) and questionnaires on lifestyle factors. On cycle day 22 of a standardized 28-day cycle, participants again completed the PSS for the previous week (second cycle exposure) and each week rated the severity (none, mild, moderate, severe) of 17 psychological and physical symptoms (e.g., crying, cramping, pain). Mixed models estimated the association between perceived stress scores and number of moderate/severe symptoms and symptom severity scores, allowing both stress and perimenstrual symptoms to vary by cycle.Adjusting for age, education, passive and active smoking, and waist/height ratio (WHtR), high stress (fourth quartile PSS) was associated with an increased risk of reportingor=8 or more (OR 7.2, 3.3-15.8) andor=5 (OR 2.5, 1.6-4.1) symptoms as moderate/severe during the perimenstrual period compared with lower stress (quartiles one, two, and three). Stress scores were positively (p0.0001) associated with increased symptom severity scores for total, psychological, and physical symptoms.These analyses show that higher perceived stress precedes an increased severity of perimenstrual symptoms. Stress reduction programs may be an effective, nonpharmaceutical treatment for physical and psychological symptom relief.

Evaluating biomarkers in epidemiological studies can be expensive and time consuming. Many investigators use techniques such as random sampling or pooling biospecimens in order to cut costs and save time on experiments. Commonly, analyses based on pooled data are strongly restricted by distributional assumptions that are challenging to validate because of the pooled biospecimens. Random sampling provides data that can be easily analyzed. However, random sampling methods are not optimal cost-efficient designs for estimating means. We propose and examine a cost-efficient hybrid design that involves taking a sample of both pooled and unpooled data in an optimal proportion in order to efficiently estimate the unknown parameters of the biomarker distribution. In addition, we find that this design can be used to estimate and account for different types of measurement and pooling error, without the need to collect validation data or repeated measurements. We show an example where application of the hybrid design leads to minimization of a given loss function based on variances of the estimators of the unknown parameters. Monte Carlo simulation and biomarker data from a study on coronary heart disease are used to demonstrate the proposed methodology. Published in 2010 by John Wiley & Sons, Ltd.

Background Overt thyroid dysfunction has been associated with adverse obstetric outcomes. However, less is known regarding subclinical hypothyroidism or thyroid autoimmunity and their relationship to pregnancy complications. Objective The purpose of this study was to examine the association between prepregnancy anti–thyroid antibodies and subclinical hypothyroidism and preterm delivery, gestational diabetes mellitus, and preeclampsia. Study Design We conducted a secondary analysis of a prospective cohort of 18- to 40-year-old women with 1–2 previous pregnancy losses (n=1193) who participated in a multicenter randomized, placebo-controlled trial of low-dose aspirin. Prepregnancy levels of thyroid-stimulating hormone, free thyroxine, thyroglobulin antibody, and thyroid peroxidase antibody were measured. Relative risks and 95% confidence intervals were estimated with the use of generalized linear models with adjustment for age and body mass index. Results Among women with an ongoing pregnancy of >20 weeks estimated gestational age, there was no association between prepregnancy thyroid-stimulating hormone level (>2.5 vs ≤2.5 mIU/L) and preterm delivery (adjusted relative risk, 0.77; 95% confidence interval, 0.40–1.47), gestational diabetes mellitus (adjusted relative risk, 1.28; 95% confidence interval, 0.54–3.04), or preeclampsia (adjusted relative risk, 1.20; 95% confidence interval, 0.71–2.04). Similarly, among women with thyroid antibodies, there was no increase in the likelihood of preterm delivery (relative risk, 1.26; 95% confidence interval, 0.65–2.45), gestational diabetes mellitus (relative risk, 1.33; 95% confidence interval, 0.51–3.49), or preeclampsia (relative risk, 1.02; 95% confidence interval, 0.54–1.92), compared with women without these antibodies. Conclusion Among women with 1–2 previous pregnancy losses, subclinical hypothyroidism and thyroid autoimmunity were not associated with an increased risk of preterm delivery, gestational diabetes mellitus, or preeclampsia. These data support current recommendations that low-risk asymptomatic women should not be screened routinely for thyroid dysfunction or autoimmunity.

Summary Investigators have long puzzled over the observation that low-birthweight babies of smokers tend to fare better than low-birthweight babies of non-smokers. Similar observations have been made with regard to factors other than smoking status, including socio-economic status, race and parity. Use of standardised birthweights, or birthweight z-scores, has been proposed as an approach to resolve the crossing of the curves that is the hallmark of the so-called birthweight paradox. In this paper, we utilise directed acyclic graphs, analytical proofs and an extensive simulation study to consider the use of z-scores of birthweight and their effect on statistical analysis. We illustrate the causal questions implied by inclusion of birthweight in statistical models, and illustrate the utility of models that include birthweight or z-scores to address those questions. Both analytically and through a simulation study we show that neither birthweight nor z-score adjustment may be used for effect decomposition. The z-score approach yields an unbiased estimate of the total effect, even when collider-stratification would adversely impact estimates from birthweight-adjusted models; however, the total effect could have been estimated more directly with an unadjusted model. The use of z-scores does not add additional information beyond the use of unadjusted models. Thus, the ability of z-scores to successfully resolve the paradoxical crossing of mortality curves is due to an alteration in the causal parameter being estimated (total effect), rather than adjustment for confounding or effect decomposition or other factors.

Objective To evaluate if antimullerian hormone (AMH) is associated with pregnancy loss. Design Prospective cohort study within a block-randomized, double-blind, placebo-controlled trial of low-dose aspirin. Setting Not applicable. Patient(s) Women (n = 1,228) were of ages 18–40 years with a history of one to two pregnancy losses and were actively attempting pregnancy without fertility treatment. Intervention(s) Not applicable. Main Outcome Measure(s) Pregnancy loss. Result(s) Relative risks (and 95% confidence interval [CIs]) of human chorionic gonadotropin (hCG)-detected and clinical pregnancy loss were assessed with the use of log binomial models with robust variance and inverse probability weights adjusted for age, race, body mass index, income, trial treatment assignment, parity, number of previous losses, and time since most recent loss. AMH levels were defined as: low ( 3.5 ng/mL; n=483). Of the 1,202 women with baseline AMH data, 19 (17.3%) with low AMH experienced a clinical loss, compared with 61 (11.4%) with normal AMH and 50 (11.8%) with high AMH levels. Low or high AMH levels, compared with normal AMH, were not associated with clinical loss. Results for hCG-detected pregnancy loss mirrored those of clinical loss. Conclusion(s) AMH values were not associated with hCG-detected or clinical pregnancy loss in unassisted conceptions in women with a history of one to two previous losses. Our data do not support routine AMH testing for prediction of pregnancy loss. Clinical Trial Registration Number NCT00467363.

Objective To identify associations between fertility treatment use (assisted reproductive technologies, ovulation induction, and artificial insemination) and subsequent infant feeding practices. Design The Upstate KIDS population-based cohort enrolled mothers who delivered live births in New York (2008-2010), sampling on fertility treatment and plurality. Setting Not applicable. Patient(s) Data regarding singletons and one randomly selected infant between twins were used. Intervention(s) Not applicable. Main Outcome Measure(s) Mothers reported breast feeding and formula feeding practices at 4, 8, and 12 months postpartum. Modified Poisson regression was used to compare risks for feeding practices by mode of conception. Marginal structural models were used to estimate the controlled direct effects of fertility treatment on feeding, independent of preterm birth. Result(s) Among 4,591 mothers, 1,361 (30%) conceived with the use of fertility treatments. Mothers who used fertility treatments were less likely to breast feed to 12 months after birth and were more likely to provide formula, solids, and juice by 4 months than mothers who did not conceive with treatments. Fertility treatment remained associated with breast feeding cessation and formula feeding in mediation analyses, suggesting that preterm birth does not fully explain these associations. Conclusion(s) Women who conceived with the use of fertility treatments were less likely to breast feed later in infancy and were more likely to provide formula, solids, and juice earlier in infancy. Our analyses accounted for confounding and preterm birth, but other contributing factors may include difficulties feeding twins or workplace breast feeding accommodations.