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Background: Pregnancy complications are associated with increased risk of development of cardiometabolic diseases and earlier mortality. However, much of the previous research has been limited to White pregnant participants. We aimed to investigate pregnancy complications in association with total and cause-specific mortality in a racially diverse cohort and evaluate whether associations differ between Black and White pregnant participants. Methods: The Collaborative Perinatal Project was a prospective cohort study of 48 197 pregnant participants at 12 US clinical centers (1959–1966). The Collaborative Perinatal Project Mortality Linkage Study ascertained participants’ vital status through 2016 with linkage to the National Death Index and Social Security Death Master File. Adjusted hazard ratios (aHRs) for underlying all-cause and cause-specific mortality were estimated for preterm delivery (PTD), hypertensive disorders of pregnancy, and gestational diabetes/impaired glucose tolerance (GDM/IGT) using Cox models adjusted for age, prepregnancy body mass index, smoking, race and ethnicity, previous pregnancies, marital status, income, education, previous medical conditions, site, and year. Results: Among 46 551 participants, 45% (21 107 of 46 551) were Black, and 46% (21 502 of 46 551) were White. The median time between the index pregnancy and death/censoring was 52 years (interquartile range, 45–54). Mortality was higher among Black (8714 of 21 107 [41%]) compared with White (8019 of 21 502 [37%]) participants. Overall, 15% (6753 of 43 969) of participants had PTD, 5% (2155 of 45 897) had hypertensive disorders of pregnancy, and 1% (540 of 45 890) had GDM/IGT. PTD incidence was higher in Black (4145 of 20 288 [20%]) compared with White (1941 of 19 963 [10%]) participants. The following were associated with all-cause mortality: preterm spontaneous labor (aHR, 1.07 [95% CI, 1.03–1.1]); preterm premature rupture of membranes (aHR, 1.23 [1.05–1.44]); preterm induced labor (aHR, 1.31 [1.03–1.66]); preterm prelabor cesarean delivery (aHR, 2.09 [1.75–2.48]) compared with full-term delivery; gestational hypertension (aHR, 1.09 [0.97–1.22]); preeclampsia or eclampsia (aHR, 1.14 [0.99–1.32]) and superimposed preeclampsia or eclampsia (aHR, 1.32 [1.20–1.46]) compared with normotensive; and GDM/IGT (aHR, 1.14 [1.00–1.30]) compared with normoglycemic. P values for effect modification between Black and White participants for PTD, hypertensive disorders of pregnancy, and GDM/IGT were 0.009, 0.05, and 0.92, respectively. Preterm induced labor was associated with greater mortality risk among Black (aHR, 1.64 [1.10–2.46]) compared with White (aHR, 1.29 [0.97–1.73]) participants, while preterm prelabor cesarean delivery was higher in White (aHR, 2.34 [1.90–2.90]) compared with Black (aHR, 1.40 [1.00–1.96]) participants. Conclusions: In this large, diverse US cohort, pregnancy complications were associated with higher mortality nearly 50 years later. Higher incidence of some complications in Black individuals and differential associations with mortality risk suggest that disparities in pregnancy health may have life-long implications for earlier mortality.

To evaluate the associations between preconception sleep characteristics and shift work with fecundability and live birth.Secondary analysis of the Effects of Aspirin in Gestation and Reproduction study, a preconception cohort.Four US academic medical centers.Women aged 18-40 with a history of 1-2 pregnancy losses who were attempting to conceive again.Not applicable.We evaluated baseline, self-reported sleep duration, sleep midpoint, social jetlag, and shift work among 1,228 women who were observed for ≤6 cycles of pregnancy attempts to ascertain fecundability. We ascertained live birth at the end of follow up via chart abstraction. We estimated fecundability odds ratios (FORs) using discrete, Cox proportional hazards models and risk ratios (RRs) for live birth using log-Poisson models.Sleep duration ≥9 vs. 7 to8 hours (FOR: 0.81, 95% confidence interval [CI], 0.61; 1.08), later sleep midpoints (3rd tertile vs. 2nd tertile: FOR: 0.85; 95% CI, 0.69, 1.04) and social jetlag (continuous per hour; FOR: 0.93, 95% CI: 0.86, 1.00) were not associated with reduced fecundability. In sensitivity analyses, excluding shift workers, sleep duration ≥9 vs. 7 to8 hours (FOR: 0.62; 95% CI, 0.42; 0.93) was associated with low fecundability. Night shift work was not associated with fecundability (vs. non-night shift work FOR: 1.17, 95% CI, 0.96; 1.42). Preconception sleep was not associated with live birth.Overall, there does not appear to be a strong association between sleep characteristics, fecundability, and live birth. Although these findings may suggest weak and imprecise associations with some sleep characteristics, our findings should be evaluated in larger cohorts of women with extremes of sleep characteristics.Clinicaltrials.gov NCT00467363.

To examine whether semen parameters are associated with live birth among couples seeking infertility treatment after accounting for semen parameter variability.Folic Acid and Zinc Supplementation Trial (FAZST) prospective cohort.Four US reproductive endocrinology and infertility care study centers, 2013-2017.Couples (n = 2,369) seeking fertility consultations at 4 US infertility care study centers.Semen volume, pH, sperm viability, morphology, progressive and total motility, concentration, count, and total and progressive motile count assessed at baseline and at 2, 4, and 6 months after enrollment.Log-binomial models stratified by fertility treatment received (in vitro fertilization [IVF], intrauterine insemination [IUI], ovulation induction [OI], or no treatment) estimated risk differences (RDs) between semen parameter quartiles and live birth and accounted for multiple semen assessments per person. We accounted for abstinence time, the biological interdependence of semen parameters, and potential selection bias because of loss to follow-up.Among couples using OI only or no treatment, 39% had a live birth, and relative to the highest quartile, the lowest quartiles of morphology (RD, -19 [95% CI, -23 to -15] per 100 couples), motility (RD, -13 [95% CI, -17 to -9]), concentration (RD, -22 [95% CI, -26 to -19]), and total motile count (RD, -18 [95% CI, -22 to -14]) were associated with fewer live births. For IUI, 26% had a live birth, and the lowest quartiles of volume (RD, -6 [95% CI, -11 to -0.4]), concentration (RD, -6 [95% CI, -11 to -0.1]), count (RD, -10 [95% CI, -15 to -4]), and total motile count (RD, -7 [95% CI, -13 to -1]) were associated with fewer live births. For IVF, 61% had a live birth, and only morphology (Q1 RD, -7 [95% CI, -14 to 0.2]; Q2 RD, -10 [95% CI, -17 to -2.2]) was associated with live birth.Semen parameters are critical in couples undergoing OI/IUI. Only low morphology was important for live birth after IVF. Although data supporting the use of semen parameters are fragmented across differing populations, current findings are generalizable across the range of male fertility and couple fertility treatments, providing evidence about which semen parameters are most relevant in which settings.NCT#01857310.

Limited data are available about the potential health effects of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on pregnant women and their developing offspring. We established the International Registry of Coronavirus Exposure in Pregnancy (IRCEP) to provide data on the risk of major adverse obstetric and neonatal outcomes among women with varying degrees of severity and timing of coronavirus disease 2019 (COVID-19) during pregnancy. We describe here the cohort and share the lessons learned. The IRCEP enrolls women tested for SARS-CoV-2 or with a clinical diagnosis of COVID-19 during pregnancy and obtains information using an online data collection system. By March 2021, 17,532 participants from 77 countries had enrolled; 54% enrolled during pregnancy and 46% afterward. Among women with symptomatic COVID-19 with a positive SARS-CoV-2 test (n = 4,934), symptoms were mild in 41%, moderate in 52%, and severe in 7%; 7.7% were hospitalized for COVID-19 and 1.7% were admitted to an intensive care unit. The biggest challenges were retention of participants enrolled during pregnancy and the potential bias introduced when participants enroll after pregnancy outcomes are known. Multiple biases need to be considered and addressed when estimating and interpreting the effects of COVID-19 in pregnancy in these types of cohorts.

Background Epigenetic mechanisms may underlie associations between maternal caffeine consumption and adverse childhood metabolic outcomes. However, limited studies have examined neonate DNA methylation (DNAm) patterns in the context of preconception or prenatal exposure to caffeine metabolites. Objective We examined preconception and pregnancy caffeine exposure with DNAm alterations in neonate cord blood (n = 378). Design In a secondary analysis of the Effects of Aspirin in Gestation and Reproduction Trial (EAGeR), we measured maternal caffeine, paraxanthine, and theobromine concentrations from stored serum collected preconception (on average 2 months before pregnancy) and at 8 weeks of gestation. In parallel, self-reported caffeinated beverage intake was captured via administration of questionnaires and daily diaries. We profiled DNAm from the cord blood buffy coat of singletons using the MethylationEPIC BeadChip. We assessed associations of maternal caffeine exposure and methylation β-values using multivariable robust linear regression. A false discovery rate (FDR) correction was applied using the Benjamini-Hochberg method. Results In preconception the majority of women reported consuming one or fewer servings/day on average and caffeine and paraxanthine metabolite levels were 88 and 36 µmol/L, respectively. Preconception serum caffeine metabolites were not associated with individual CpG sites (FDR > 5%), though pregnancy theobromine was associated with DNAm at cg09460369 near RAB2A (β = 0.028; SE = 0.005; FDR P = 0.012). Preconception self-reported caffeinated beverage intake compared to no intake was associated with DNAm at cg09002832 near GLIS3 (β = -0.013; SE = 0.002; FDR P = 0.036). No associations with self-reported intake during pregnancy were found. Conclusions Few effects of maternal caffeine exposure on neonate methylation differences in leukocytes were identified in this relatively low caffeine consumption population.Clinical Trial Registry: #NCT00467363.

Objective To determine if 6-month folic acid (5 mg) and zinc (30 mg) supplementation impacts sperm DNA methylation patterns. Design A multicenter, double-blind, block randomized, placebo-controlled trial titled “The Folic Acid and Zinc Supplementation Trial (FAZST).” Setting Infertility care centers. Patient(s) Male partners (18 years and older) from heterosexual couples (female partners aged 18–45 years) seeking fertility treatment were recruited. Intervention(s) Men were randomized 1:1 to receive folic acid (5 mg) and elemental zinc (30 mg) (n = 713) or a matching placebo (n = 757) daily for 6 months. Main Outcome Measure(s) Sperm DNA methylation was analyzed using the EPIC methylation array (Illumina) at 6 months. Differential sperm DNA methylation was assessed at multiple levels (regional, single cytosine phosphate guanine, etc.). We additionally assessed the impact of supplementation on epigenetic age. Result(s) No significant differences were identified between the treatment and placebo groups although some trends appeared to be present. To determine if these trends were noteworthy, we implemented various permutations and found that the patterns we identified were no more than would be expected by random chance. Conclusion(s) The data presented here strongly suggest that this supplementation regimen is not effective at altering sperm DNA methylation. These data comport well with previous findings from the FAZST study that found no impact of supplementation on basic semen analysis parameters or live birth. Clinical Trial Registration Number ClinicalTrials.gov Identifier: NCT01857310.

The average causal effect compares counterfactual outcomes if everyone had been exposed versus if everyone had been unexposed, which can be an unrealistic contrast. Alternatively, we can target effects that compare counterfactual outcomes against the factual outcomes observed in the sample (i.e., we can compare against the natural course). Here, we demonstrate how the natural course can be estimated and used in causal analyses for model validation and effect estimation. Our example is an analysis assessing the impact of taking aspirin on pregnancy, 26 weeks after randomization, in the Effects of Aspirin in Gestation and Reproduction trial (United States, 2006–2012). To validate our models, we estimated the natural course using g-computation and then compared that against the observed incidence of pregnancy. We observed good agreement between the observed and model-based natural courses. We then estimated an effect that compared the natural course against the scenario in which participants assigned to aspirin always complied. If participants had always complied, there would have been 5.0 (95% confidence interval: 2.2, 7.8) more pregnancies per 100 women than was observed. It is good practice to estimate the natural course for model validation when using parametric models, but whether one should estimate a natural course contrast depends on the underlying research questions.

STUDY QUESTION Is preconception leukocyte telomere length associated with fecundability, pregnancy loss and live birth among women attempting natural conception with a history of 1–2 prior pregnancy losses? SUMMARY ANSWER Preconception leukocyte telomere length is not associated with fecundability, pregnancy loss or live birth. WHAT IS KNOWN ALREADY As women increasingly delay childbearing, accessible preconception biomarkers to predict pregnancy outcomes among women seeking natural conception could improve preconception counseling. Findings of small case–control or cross-sectional studies suggest that telomere attrition is associated with adverse pregnancy outcomes among women undergoing fertility treatment, but prospective studies in non-clinical populations are lacking. STUDY DESIGN, SIZE, DURATION Participants included 1228 women aged 18–40 years with a history of 1–2 prior pregnancy losses who were recruited at four university medical centers (2006–2012). PARTICIPANTS/MATERIALS, SETTING, METHODS Preconception leukocyte telomere length was measured at baseline using PCR and reported as a ratio (T/S) in relation to population-specific standard reference DNA. Women were followed for up to six cycles while attempting to conceive. Associations of telomere length with fecundability, live birth and pregnancy loss were estimated using discrete Cox proportional hazards models and log-binomial models. MAIN RESULTS AND THE ROLE OF CHANCE After adjustment for age, BMI, smoking and other factors, preconception telomere length was not associated with fecundability (Q4 vs Q1 FOR = 1.00; 95% CI = 0.79, 1.27), live birth (Q4 vs Q1 RR = 1.00; 95% CI = 0.85, 1.19), or pregnancy loss (Q4 vs Q1 RR = 1.12; 95% CI = 0.78, 1.62). LIMITATIONS, REASONS FOR CAUTION Telomere length was measured in leukocytes, which is an accessible tissue in women attempting natural conception but may not reflect telomere length in oocytes. Most women were younger than 35 years, limiting our ability to evaluate associations among older women. Participants had a history of 1–2 prior pregnancy losses; therefore, our findings may not be widely generalizable. WIDER IMPLICATIONS OF THE FINDINGS Despite prior research suggesting that telomere length may be associated with pregnancy outcomes among women seeking fertility treatment, our findings suggest that leukocyte telomere length is not a suitable biomarker of pregnancy establishment or maintenance among women attempting natural conception. STUDY FUNDING/COMPETING INTEREST(S) 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, MD, USA; contract numbers HHSN267200603423, HHSN267200603424 and HHSN267200603426). The authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER The trial was registered with ClinicalTrials.gov, number NCT00467363.

Maternal adaptations may vary by foetal sex. Whether male infants influence long-term mortality in mothers remains uncertain.The objective of the study was to examine whether male infants increase the risk of maternal mortality.This study included pregnant women enrolled at 12 US sites from 1959 to 1966 in the Collaborative Perinatal Project (CPP). Collaborative Perinatal Project records were linked to the National Death Index and the Social Security Master Death File to ascertain deaths until 2016. Foetal sex was determined by infant sex at birth, defined as the total number of male or female infants in pregnancies prior to or during enrolment in the CPP. In secondary analyses, exposure was defined as infant sex at the last CPP delivery. Outcomes included all-cause and underlying causes of mortality. We used Cox proportional hazards models weighted by the number of prior live births and stratified our models by parity and race/ethnicity.Among 48,188 women, 50.8% had a male infant at their last registered CPP pregnancy and 39.0% had a recorded death after a mean follow-up of 47.8 years (SD 10.5 years). No linear association was found between the number of liveborn males and all-cause mortality (primipara women: HR 1.02, 95% CI 0.95, 1.09, multipara women, 1 prior live birth: HR 0.96, 95% CI 0.89, 1.03, multipara women, ≥2 prior live births: HR 0.97, 95% CI 0.85, 1.11). A similar trend was noted for cardiovascular- and cancer-related mortality. At the last delivery, women with a male infant did not have an increased risk of all-cause or cause-specific mortality compared to women with a female infant. These findings were consistent across racial/ethnic groups.Women who give birth to male infants, regardless of number, are not at increased risk of all-cause and cause-specific mortality. These findings suggest that giving birth to male infants may not independently influence the long-term health of women.

Background Cadmium is an endocrine disrupting chemical that affects the hypothalamic-pituitary-gonadal axis. Though evidence suggests its potential role in altering androgen synthesis and metabolic pathways that are characteristic of polycystic ovary syndrome (PCOS), its relation in healthy women of reproductive age is largely unknown. As women with mild sub-clinical features of PCOS who do not meet the diagnostic criteria of PCOS may still experience reduced fecundability, investigating associations between cadmium and PCOS-phenotypes among healthy women may provide unique insight into the reproductive implications for many on the PCOS spectrum. Therefore, the objective of this study was to evaluate associations between cadmium and androgens, anti-Müllerian hormone (AMH), and metabolic markers in women of reproductive age. Methods This was a prospective cohort study of 251 healthy premenopausal women without self-reported PCOS (mean age 27.3 years and BMI 24.1 kg/m2). Cadmium was measured in blood collected at baseline. Reproductive hormones and metabolic markers were measured in fasting serum 8 times per menstrual cycle for 2 cycles. Linear mixed models and Poisson regression with a robust error variance were used to examine associations between cadmium and reproductive hormones and metabolic markers and anovulation, respectively. Results Median (interquartile range) blood cadmium concentrations at baseline were 0.30 (0.19–0.43) µg/L. Higher levels of testosterone (2.2 %, 95 % confidence interval [CI] 0.4, 4.1), sex hormone-binding globulin (2.9 %, 95 % CI 0.5, 5.5), and AMH (7.7 %, 95 % CI 1.1, 14.9) were observed per 0.1 µg/L increase in cadmium concentrations. An 18 % higher probability of a mild PCOS-phenotype (95 % CI 1.06, 1.31), defined by a menstrual cycle being in the highest quartile of cycle-averaged testosterone and AMH levels, was also found per 0.1 µg/L increase in cadmium levels. No associations were observed for insulin and glucose. These findings were consistent even after analyses were restricted to non-smokers or further adjusted for dietary factors to account for potential sources of exposure. Conclusions Overall, among healthy reproductive-aged women, cadmium was associated with endocrine features central to PCOS, but not with metabolic markers. These suggest its potential role in the hormonal milieu associated with PCOS even at low levels of exposure.

The annual meeting of the Society for Epidemiologic Research (SER) is a major forum for sharing new research and promoting the career development of participants. Because of this, evaluating representation in key presentation formats is critical. For the 3,257 presentations identified at the 2015–2017 SER annual meetings, we evaluated presenter characteristics, including gender, affiliation, subject area, and h-index, and representation in 3 highlighted presentation formats: platform talks (n = 382), invited symposium talks (n = 273), and chairing a concurrent contributed session or symposium (n = 188). Data were abstracted from SER records, abstract booklets, and programs. Gender was assessed using GenderChecker software, and h-index was determined using the Scopus application programming interface. Log-binomial models were adjusted for participant characteristics and conference year. In adjusted models, women were less likely than men to present an invited symposium talk (relative risk = 0.60, 95% confidence interval: 0.45, 0.81) compared with all participants with accepted abstracts. Researchers from US public universities, US government institutions, and international institutions were less likely to present a symposium talk or to chair a concurrent contributed session or symposium than were researchers from US private institutions. The research areas that were most represented in platform talks were epidemiologic methods, social epidemiology, and cardiovascular epidemiology. Our findings suggest differences in representation by gender, affiliation, and subject area after accounting for h-index.

Anti-müllerian hormone (AMH) is an established marker of ovarian reserve that decreases with age. Though the pool of ovarian follicles is established during fetal development, impacts of in utero exposures on AMH are uncertain. Thus, we sought to evaluate associations of in utero exposures with AMH of adult daughters with a prospective cohort study of adult daughters at university medical centers. Women noted their mother’s reported use of diethylstilbestrol (DES), vitamins, tobacco, alcohol, and caffeine during pregnancy, and their mother’s occupation during pregnancy. All participants were reproductive age women (18–40 years) enrolled in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial. Serum AMH concentrations were measured at baseline prior to conception and categorized using clinical guidelines. Multinomial regression models estimated associations between each exposure and high (>3.5 ng/mL) and low (

We have recently shown that sperm epigenetic age (SEA), a surrogate measure of biological aging in sperm, is associated with couples' time-to-pregnancy (TTP). Advanced SEA was also observed among smokers, suggesting its susceptibility to environmental exposures. Therefore, we assessed the association between urinary phthalate metabolites and SEA in male partners of couples planning to conceive among the general population.The Longitudinal Investigation of Fertility and the Environment (LIFE) Study was a prospective multi-site and general population cohort study of couples who were interested in becoming pregnant. Among male partners (n = 333), eleven urinary phthalate metabolites were measured and SEA was previously developed using Super Learner ensemble algorithm. Multivariable linear regression was used to evaluate associations of SEA with individual metabolites. Bayesian kernel machine regression (BKMR), quantile g-computation (qgcomp) and weighted quantile sum (WQS) models were used for mixture analyses. Covariates included were BMI, cotinine, race and urinary creatinine.In the single metabolite multivariate analyses, nine (82%) phthalate metabolites displayed positive trends with SEA (range: 0.05-0.47 years). Of these metabolites, advanced SEA was significantly associated with interquartile range increases in exposure of three phthalates [MEHHP (β = 0.23, 95% CI: 0.03, 0.43, p = 0.03), MMP (β = 0.24, 95% CI: 0.01, 0.47, p = 0.04), and MiBP (β = 0.47, 95% CI: 0.14, 0.81, p = 0.01)]. Additionally, in BKMR and qgcomp (p = 0.06), but not WQS models, phthalate mixtures showed an overall positive trend with SEA, with MiBP, MMP and MBzP as major drivers of the mixture effects.This is the first study that combined single exposure and mixture models to associate male phthalate exposures with advanced epigenetic aging of sperm in men planning to conceive among the general population. Our findings suggest that phthalate exposure may contribute to the acceleration of biological aging of sperm.

We evaluated relationships between preconception adiposity and human offspring sex and sex ratio. Using data from a prospective preconception cohort nested within a randomized controlled trial based at 4 US clinical sites (2006–2012), we used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for male:female sex ratio, and log-identity regression to estimate risk differences (RDs) and 95% CIs for male and female livebirth according to preconception adiposity measures. Inverse-probability weights accounted for potential selection bias. Among 603 women attempting pregnancy, there were meaningful reductions in sex ratio for the highest category of each adiposity measure. The lowest sex ratios were observed for obesity (body mass index of ≥30, calculated as weight (kg)/height (m)2, OR = 0.48, 95% CI: 0.26, 0.88) relative to normal body mass index, and the top tertiles (tertile 3) of serum leptin (OR = 0.50, 95% CI: 0.32, 0.80) and skinfold measurements (OR = 0.50, 95% CI: 0.32, 0.79) relative to the lowest tertiles. Reductions were driven by 11–15 fewer male livebirths per 100 women (for obesity, RD = −15, 95% CI: −23, −6.7; for leptin tertile 3, RD = −11, 95% CI: −20, −3.2; and for skinfolds tertile 3, RD = −11, 95% CI: −19, −3.3). We found that relationships between preconception adiposity measures and reduced sex ratio were driven by a reduction in male births.

STUDY QUESTION Do sperm mitochondrial DNA measures predict probability of pregnancy among couples in the general population? SUMMARY ANSWER Those with high sperm mitochondrial DNA copy number (mtDNAcn) had as much as 50% lower odds of cycle-specific pregnancy, and 18% lower probability of pregnancy within 12 months. WHAT IS KNOWN ALREADY Semen parameters have been found to poorly predict reproductive success yet are the most prevalent diagnostic tool for male infertility. Increased sperm mtDNAcn and mitochondrial DNA deletions (mtDNAdel) have been associated with decreased semen quality and lower odds of fertilization in men seeking fertility treatment. STUDY DESIGN, SIZE, DURATION A population-based prospective cohort study of couples discontinuing contraception to become pregnant recruited from 16 US counties from 2005 to 2009 followed for up to 16 months. PARTICIPANTS/MATERIALS, SETTING, METHODS Sperm mtDNAcn and mtDNAdel from 384 semen samples were assessed via triplex probe-based quantitative PCR. Probability of pregnancy within 1 year was compared by mitochondrial DNA, and discrete-time proportional hazards models were used to evaluate the relations with time-to-pregnancy (TTP) with adjustment for covariates. MAIN RESULTS AND THE ROLE OF CHANCE Higher sperm mtDNAcn was associated with lower pregnancy probability within 12 months and longer TTP. In unadjusted comparisons by quartile (Q), those in Q4 had a pregnancy probability of 63.5% (95% CI: 53.1% to 73.1%) compared to 82.3% (95% CI: 73.2% to 89.9%) for Q1 (P = 0.002). Similar results were observed in survival analyses adjusting for covariates to estimate fecundability odds ratios (FORs) comparing mtDNAcn in quartiles. Relative to those in Q1 of mtDNAcn, FORs (95% CI) were for Q2 of 0.78 (0.52 to 1.16), Q3 of 0.65 (0.44 to 0.96) and Q4 of 0.55 (0.37 to 0.81), and this trend of decreasing fecundability with increasing mtDNAcn quartile was statistically significant (FOR per log mtDNAcn = 0.37; P LIMITATIONS, REASONS FOR CAUTION This prospective cohort study consisted primarily of Caucasian men and women and thus large diverse cohorts are necessary to confirm the associations between sperm mtDNAcn and couple pregnancy success in other races/ethnicities. WIDER IMPLICATIONS OF THE FINDINGS Our results demonstrate that sperm mtDNAcn has utility as a biomarker of male reproductive health and probability of pregnancy success in the general population. STUDY FUNDING/COMPETING INTEREST(S) This work was funded in part by the National Institute of Environmental Health Sciences, National Institutes of Health (R01-ES028298; PI: J.R.P.) and the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (Contracts N01-HD-3-3355, N01-HD-3-3356 and N01-HD-3-3358). The authors declare no competing interests. TRIAL REGISTRATION NUMBER N/A

BACKGROUND: Attaining pregnancy is conditional upon a series of complex processes, including adequately timed intercourse, ovulation, fertilization, and implantation. Anovulation is a first line treatment target for couples with difficulty conceiving and is frequently examined in studies of fecundability. OBJECTIVES: To identify whether sporadic anovulation is an important determinant of cumulative pregnancy rates and time to pregnancy among fertile women with regular menstrual cycles. METHODS: We simulated cumulative pregnancy rates and time to pregnancy for 12 consecutive menstrual cycles among 100,000 women based on data-driven probabilities of implantation, fertilization, ovulation, and intercourse occurring in the fertile window. We assumed anovulation probabilities of 1%, 8%, or 14.5% and intercourse averaging once per week, every other day, and daily. The model incorporated reductions in implantation and fertilization rates for successive cycles of non-pregnancy. RESULTS: After 12 cycles, a reduction in the per-cycle incidence of anovulation from 14.5% to 1% resulted in a 4.0% higher cumulative pregnancy rate (86.7 versus 90.7%) and similar time to pregnancy (1-cycle median difference). In contrast, increasing mean unscheduled sexual intercourse frequency from weekly to every other day was associated with a 5-cycle median reduction in time to pregnancy (weekly: 7 cycles; every other day or daily: 2 cycles) and a 28.9% increase in the cumulative pregnancy rate (weekly: 59.9%, every other day: 88.8%; daily: 91.6%). CONCLUSIONS: In presumed fertile women with regular menstrual cycles, routine investigation of anovulation may not be an informative outcome in studies of fecundability, and routine testing to ensure ovulation and treatment of anovulation are unlikely to be medically necessary. While biomarkers or cervical fluid may help time intercourse to the fertile window, time to pregnancy can also be improved through increasing the frequency of unscheduled intercourse. These findings need corroboration in large preconception time to pregnancy studies.

Preeclampsia and gestational hypertension are common complications of pregnancy associated with significant maternal and infant morbidity. Despite extensive research evaluating risk factors during pregnancy, most women who develop a hypertensive disorder of pregnancy are not considered high-risk and strategies for prevention remain elusive. We evaluated preconception blood pressure and its change into early pregnancy as novel risk markers for development of a hypertensive disorder of pregnancy. The EAGeR (Effects of Aspirin in Gestation and Reproduction) trial (2007–2011) randomized 1228 healthy women with a history of pregnancy loss to preconception-initiated low-dose aspirin versus placebo and followed participants for up to 6 menstrual cycles attempting pregnancy and throughout pregnancy if they became pregnant. Blood pressure was measured during preconception and throughout early gestation. The primary outcomes, preterm preeclampsia, term preeclampsia, and gestational hypertension, were abstracted from medical records. Among 586 women with a pregnancy >20 weeks’ gestation, preconception blood pressure levels were higher for preterm preeclampsia (87.3±6.7 mm Hg mean arterial pressure), term preeclampsia (88.3±9.8 mm Hg), and gestational hypertension (87.9±9.1 mm Hg) as compared with no hypertensive disorder of pregnancy (83.9±8.6 mm Hg). Change in blood pressure from preconception into very early pregnancy was associated with development of preeclampsia (relative risk, 1.13 [95% CI, 1.02–1.25] per 2 mm Hg increase in mean arterial pressure at 4 weeks’ gestation), particularly preterm preeclampsia (relative risk, 1.21 [95% CI, 1.01–1.45]). Randomization to aspirin did not alter blood pressure trajectory or risk of hypertension in pregnancy. Preconception blood pressure and longitudinal changes during early pregnancy are underexplored but crucial windows in the detection and prevention of hypertensive disorders of pregnancy. Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00467363.

Background Opioids are commonly prescribed to women of reproductive age, including after delivery and miscarriage. However, to our knowledge, opioid use has not been frequently studied in relation to the common reproductive complications of impaired fecundability and pregnancy. We examined the association of opioid use during the critical window of pregnancy establishment with fecundability and pregnancy loss. Methods We measured opioid use by urine screening and self-report at multiple time points during preconception and early pregnancy in a prospective cohort of women attempting conception (n=1228). The main outcomes included time to hCG-detected pregnancy and incidence of live birth and pregnancy loss. We estimated fecundability odds ratios (FOR) and risk ratios (RR) with 95% confidence intervals (CI) adjusting for sociodemographic characteristics, reproductive characteristics, and use of antidepressants, tobacco, alcohol, and marijuana. Results Prevalence of preconception opioid use was 18% (n=226 of 1228), and in early pregnancy was 5% (n=33 of 685). Opioid use while attempting pregnancy was associated with reduced fecundability (FOR: 0.71; 95% CI: 0.50, 1.0). Risk of pregnancy loss increased as opioid exposure was detected later in gestation, from the beginning of the cycle of conception (RR: 1.5; 95% CI 0.85, 2.6), to week 4 of pregnancy (RR: 2.1; 95% CI: 1.1, 4.1), and to week 4 and 8 of pregnancy (RR: 2.5; 95% CI: 1.3, 5.0). Conclusions Our results are consistent with the hypothesis that opioid exposure while trying to conceive may be harmful, even among healthy, non-opioid-dependent women. Possible risks to fecundability and pregnancy viability are relevant to patients and providers when evaluating pain management approaches.ClinicalTrials.gov registration number: #NCT00467363.

Summary Objective Obesity has become a major, worldwide public health issue and is associated with a greater risk of adverse pregnancy outcomes. Leptin, a hormone produced by adipocytes, is elevated in individuals with obesity and may mediate the association between obesity and pregnancy outcomes. Though leptin levels during pregnancy have been associated with pregnancy outcomes, less is understood regarding preconception levels. Therefore, the objective of this study was to evaluate associations between preconception leptin levels and adverse pregnancy outcomes. Methods This was a prospective cohort study nested within a large randomized controlled trial conducted at four medical centres in the United States. A total of 1078 women completed the parent study; this analysis involved women who became pregnant during that study (n = 776). Patients were healthy women, ages 18 to 40, attempting to conceive, with 1 to 2 prior pregnancy losses. Participants were followed for less than or equal to 6 cycles while trying to conceive and throughout pregnancy if they conceived. Preconception leptin concentrations were measured in serum collected at baseline then categorized by tertiles (using the lowest as reference group). Weighted log‐binomial regression estimated risk ratios (RR) and 95% confidence intervals (CIs) for pregnancy loss, preterm delivery (PTD), gestational diabetes (GDM), and hypertensive disorders in pregnancy, adjusting for age, waist‐to‐hip ratio (WHR), and body mass index (BMI). Results The mean (SD) BMI in this cohort was 25.4 ± 6.0. GDM (RR 18.37; 95% CI, 2.39‐141.55) and hypertensive disorders of pregnancy (RR 2.35; 95% CI, 1.20‐4.61) risks were higher among women in the high tertile after adjusting for age and WHR. The associated risk persisted when adjusting for BMI for GDM but was attenuated for hypertensive disorders in pregnancy. Leptin levels were not associated with risk of pregnancy loss or PTD. Conclusions Women with higher baseline preconception leptin levels had a higher likelihood of experiencing some adverse pregnancy outcomes including GDM and hypertensive disorders of pregnancy. These findings warrant further evaluation, especially in light of the association between leptin and obesity.

STUDY QUESTION How do the calciotropic hormones (25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and intact parathyroid hormone (iPTH)) vary across the menstrual cycle and do cyclic patterns of reproductive hormones (estradiol, progesterone, LH, FSH) differ by vitamin D status? SUMMARY ANSWER Calciotropic hormones vary minimally across the menstrual cycle; however, women with 25-hydroxyvitamin D below 30 ng/ml have lower mean estradiol across the menstrual cycle. WHAT IS KNOWN ALREADY Prior human studies suggest that vitamin D status is associated with fecundability, but the mechanism is unknown. Exogenous estrogens and prolonged changes in endogenous estradiol (pregnancy or menopause) influence concentrations of 25-hydroxyvitamin D. In vitro, treatment with 1,25-dihydroxyvitamin D increases steroidogenesis in ovarian granulosa cells. There are little data about changes in calciotropic hormones across the menstrual cycle or cyclic patterns of reproductive hormones by categories of vitamin D status. STUDY DESIGN, SIZE, DURATION A prospective cohort study of 89 self-identified white women aged 18–44, across two menstrual cycles. Participants were a subset of the BioCycle Study, a community-based study conducted at the University of Buffalo, 2005–2007. PARTICIPANTS/MATERIALS, SETTING, METHODS Eligible participants had self-reported regular menstrual cycles between 21 and 35 days and were not using hormonal contraception or vitamins. Early morning fasting blood samples were drawn at up to eight study visits per cycle. Visits were timed to capture information in all cycle phases. Serum samples for 89 women (N = 163 menstrual cycles) were analyzed for estradiol, progesterone, LH, FSH and 25-hydroxyvitamin D (25(OH)D). Variability in calciotropic hormones within and across menstrual cycles was assessed using intraclass correlation coefficients and non-linear mixed models. Given the relative stability of the calciotropic hormones across the menstrual cycle, non-linear mixed models were used to examine differences in the cyclic patterns of estradiol, progesterone, LH and FSH by categories of each calciotropic hormone (split at the median). These models were conducted for all ovulatory cycles (N = 142 ovulatory menstrual cycles) and were adjusted for age, BMI (measured in clinic) and self-reported physical activity. MAIN RESULTS AND THE ROLE OF CHANCE Median 25(OH)D concentration was 29.5 ng/ml (SD 8.4), and only 6% of women had vitamin D deficiency ( LIMITATIONS, REASONS FOR CAUTION Women included in this study had self-reported ‘regular’ menstrual cycles and very few were found to have 25(OH)D deficiency. This limits our ability to examine cycle characteristics, anovulation and the effects of concentrations of the calciotropic hormones found in deficient individuals. Additionally, the results may not be generalizable to women with irregular cycles, other races, or populations with a higher prevalence of vitamin D deficiency. WIDER IMPLICATIONS OF THE FINDINGS These findings support current clinical practice that does not time testing for vitamin D deficiency to the menstrual cycle phase. We find that women with lower vitamin D status (lower 25(OH)D or higher iPTH) have lower mean concentrations of estradiol across the menstrual cycle. Although this study cannot identify a mechanism of action, further in vitro work or clinical trials may help elucidate the biologic mechanisms linking calciotropic and reproductive hormones. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Intramural Research Programs of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contract numbers: HHSN275200403394C, HHSN275201100002I and Task 1 HHSN27500001) and the National Institute of Environmental Health Sciences. There are no competing interests.

Over the past century, the field of epidemiology has evolved and adapted to changing public health needs. Challenges include newly emerging public health concerns across broad and diverse content areas, new methods, and vast data sources. We recognize the need to engage and educate the next generation of epidemiologists and prepare them to tackle these issues of the 21st century. In this commentary, we suggest a skeleton framework upon which departments of epidemiology should build their curriculum. We propose domains that include applied epidemiology, biological and social determinants of health, communication, creativity and ability to collaborate and lead, statistical methods, and study design. We believe all students should gain skills across these domains to tackle the challenges posed to us. The aim is to train smart thinkers, not technicians, to embrace challenges and move the expanding field of epidemiology forward.

BackgroundComplex diseases have multifactorial etiologies making clinically actionable diagnostic markers difficult to identify. Novel tools with higher diagnostic yield and utility in driving personalized care are needed.MethodsWe utilized Illumina methylation array data from over 2400 samples to assess DNA methylation patterns in 20 distinct cell types ranging from sperm to brain as well as various disease states. We generated a simple analysis pipeline for DNA methylation data that focuses on intra-individual methylation variability within gene promoters. The analysis is designed, not to identify single causative gene alterations but instead focuses on any movement away from “healthy” methylation. This approach identifies altered regulation across multiple genes in related pathways thus enabling us to detect shifts in gene regulatory activity associated with distinct tissues and phenotypes. We explored three distinct questions in our assessment. 1) Are patterns of epigenetic variability tissue specific? 2) Do diseased tissues exhibit altered variability patterns compared to normal tissue? 3) Can epigenetic variability be detected in complex disease?ResultsUnsupervised clustering analyses established that patterns of epigenetic variability are tissue specific and that these patterns are at least as predictive of tissue type as differential methylation analysis. We demonstrated the ability to use these patterns to differentiate between healthy and diseased tissue with unsupervised clustering even in cases of complex multifactorial diseases. We applied this method to the clinical use case of male infertility and found that men undergoing intrauterine insemination (IUI) with the lowest number of epigenetically dysregulated promoters in their sperm were almost twice as likely to father a child than men participating in IUI with the highest number of dysregulated promoters (p=0.011). We saw no significant difference in birth rates between groups of men with high and low numbers of dysregulated promoters undergoing in vitro fertilization (IVF), indicating IVF as a better treatment than IUI to achieve live birth in the presence of multi-pathway dysregulation in sperm.ConclusionsThis study demonstrates that patterns of epigenetic variability can differentiate between tissue types. While intuitive, this finding has never been demonstrated previously and suggests that specific epigenetic variability patterns may be used to predict phenotypic changes in disease states as these are, by definition, functional changes to cellular phenotypes. We demonstrate that the variability of gene regulatory marks are distinct between healthy and diseased tissue. This is particularly apparent at genes known to be important to cell function of the tissue of interest. While in some cases these regional alterations can be seen across the entire genome, more often the regulatory alterations that define a pathological phenotype are restricted to genes of known importance to a particular tissue. Importantly, in the case of sperm, we found that these patterns of variability did have utility in predicting infertile patients who would conceive through intrauterine insemination (IUI). We would propose that this discriminatory ability is due to the fact that the signature can be assessed in an n-of-1 context and that the patterns of variability identify any shift away from regulatory normalcy in pathways known to be impactful in the tissue of interest, and not only assessing the presence or absence of rare genetic variants. While the data presented here are encouraging, more work needs to be performed in other tissues to determine when, and in what context, these findings could be clinically actionable.

Introduction In epidemiology, generalized linear models are the main statistical methods used to explore associations. However, the use of other methods such as Structural Equation Modelling (SEM) is gradually increasing. Objective The aim of the study was to illustrate the use of SEM in the assessment of salivary cortisol concentration in infants as a biomarker of perinatal exposure to inorganic arsenic. Material and methods This was a cohort study of pregnant women recruited from public health care centres in Arica, Chile, in 2013. Socio-demographic information and urine samples to assess inorganic arsenic were collected during the second trimester of pregnancy. Saliva samples were collected to assess cortisol in infants between 18–24 months of age. Four linear regression models (LRMs) and two SEMs were run to estimate the effect of prenatal exposure to inorganic arsenic on cortisol concentration in infants. Results According to LRMs and SEMs, prenatal exposure to inorganic arsenic and salivary cortisol were not associated. However, the association between maternal cortisol and cortisol in infants was statistically significant in all models; for each increase in standard deviation of the covariate Ln(maternal cortisol), the outcome Ln(cortisol in infant) increased by 0.49 units of variance in both SEMs. Conclusions LRMs and SEMs were useful to assess the effect of prenatal exposure to inorganic arsenic on cortisol in infants. However, SEM allowed the adjustment of estimations by an estimated latent that obtained the information about income, occupation, education and ethnicity in a more comprehensive way than achieved by LRM.

STUDY QUESTION: Is sperm epigenetic aging (SEA) associated with probability of pregnancy among couples in the general population? SUMMARY ANSWER: We observed a 17% lower cumulative probability at 12 months for couples with male partners in the older compared to the younger SEA categories. WHAT IS KNOWN ALREADY: The strong relation between chronological age and DNA methylation profiles has enabled the estimation of biological age as epigenetic ‘clock’ metrics in most somatic tissue. Such clocks in male germ cells are less developed and lack clinical relevance in terms of their utility to predict reproductive outcomes. STUDY DESIGN, SIZE, DURATION: This was a population-based prospective cohort study of couples discontinuing contraception to become pregnant recruited from 16 US counties from 2005 to 2009 and followed for up to 12 months. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sperm DNA methylation from 379 semen samples was assessed via a beadchip array. A state-of-the-art ensemble machine learning algorithm was employed to predict age from the sperm DNA methylation data. SEA was estimated from clocks derived from individual CpGs (SEA(CpG)) and differentially methylated regions (SEA(DMR)). Probability of pregnancy within 1 year was compared by SEA, and discrete-time proportional hazards models were used to evaluate the relations with time-to-pregnancy (TTP) with adjustment for covariates. MAIN RESULTS AND THE ROLE OF CHANCE: Our SEA(CpG) clock had the highest predictive performance with correlation between chronological and predicted age (r = 0.91). In adjusted discrete Cox models, SEA(CpG) was negatively associated with TTP (fecundability odds ratios (FORs)=0.83; 95% CI: 0.76, 0.90; P = 1.2×10(−5)), indicating a longer TTP with advanced SEA(CpG). For subsequent birth outcomes, advanced SEA(CpG) was associated with shorter gestational age (n = 192; −2.13 days; 95% CI: −3.67, −0.59; P = 0.007). Current smokers also displayed advanced SEA(CpG) (P

Background: Maternal prenatal stress is associated with physiologic and adverse mental health outcomes in the offspring, but the underlying biologic mechanisms are unknown. We examined the associations of maternal perceived stress, including preconception exposure, with DNA methylation (DNAm) alterations in the cord blood buffy coats of 358 singleton infants. Methods: Maternal perceived stress was measured prior to and throughout pregnancy in a cohort of women enrolled in Effects of Aspirin in Gestation and Reproduction Trial (EAGeR) trial. Perceived stress assessments based on a standardized Likert-scale were obtained in periconception (~2 months preconception and 2-8 weeks of gestation) and pregnancy (8-36 weeks of gestation). Cumulative perceived stress was estimated by calculating the predicted area under the curve of stress reported prior to and during pregnancy. DNAm was measured by the Infinium MethylationEPIC BeadChip. Multivariable robust linear regression was used to assess associations of perceived stress with individual CpG probes. Results: Based on a 0 to 3 scale, average reported preconception and early pregnancy stress were 0.76 (0.60) and 0.67 (0.50), respectively. Average mid- to late-pregnancy stress, based on a 0 to 10 scale, was 4.9 (1.6). Neither periconception nor pregnancy perceived stress were associated with individual CpG sites in neonatal cord blood (all false discovery rate [FDR] >5%). Conclusion: No effects of maternal perceived stress exposure on array-wide cord blood neonatal methylation differences were found.

There are important challenges to the estimation and identification of average causal effects in longitudinal data with time-varying exposures. Here, we discuss the difficulty in meeting the positivity condition. Our motivating example is the per-protocol analysis of the Effects of Aspirin in Gestation and Reproduction (EAGeR) Trial. We estimated the average causal effect comparing the incidence of pregnancy by 26 weeks that would have occurred if all women had been assigned to aspirin and complied versus the incidence if all women had been assigned to placebo and complied. Using flexible targeted minimum loss-based estimation, we estimated a risk difference of 1.27% (95% CI: −9.83, 12.38). Using a less flexible inverse probability weighting approach, the risk difference was 5.77% (95% CI: −1.13, 13.05). However, the cumulative probability of compliance conditional on covariates approached 0 as follow-up accrued, indicating a practical violation of the positivity assumption, which limited our ability to make causal interpretations. The effects of nonpositivity were more apparent when using a more flexible estimator, as indicated by the greater imprecision. When faced with nonpositivity, one can use a flexible approach and be transparent about the uncertainty, use a parametric approach and smooth over gaps in the data, or target a different estimand that will be less vulnerable to positivity violations.

Effect measure modification is often evaluated using parametric models. These models, although efficient when correctly specified, make strong parametric assumptions. While nonparametric models avoid important functional form assumptions, they often require larger samples to achieve a given accuracy. We conducted a simulation study to evaluate performance tradeoffs between correctly specified parametric and nonparametric models to detect effect modification of a binary exposure by both binary and continuous modifiers. We evaluated generalized linear models and doubly robust (DR) estimators, with and without sample splitting. Continuous modifiers were modeled with cubic splines, fractional polynomials, and nonparametric DR-learner. For binary modifiers, generalized linear models showed the greatest power to detect effect modification, ranging from 0.42 to 1.00 in the worst and best scenario, respectively. Augmented inverse probability weighting had the lowest power, with an increase of 23% when using sample splitting. For continuous modifiers, the DR-learner was comparable to flexible parametric models in capturing quadratic and nonlinear monotonic functions. However, for nonlinear, nonmonotonic functions, the DR-learner had lower integrated bias than splines and fractional polynomials, with values of 141.3, 251.7, and 209.0, respectively. Our findings suggest comparable performance between nonparametric and correctly specified parametric models in evaluating effect modification.

Pregnancy loss is a common reproductive complication, but its association with long-term mortality and whether this varies by maternal race/ethnicity is not well understood. Data from a racially diverse cohort of pregnant women enrolled in the Collaborative Perinatal Project (CPP) from 1959 to 1966 were used for this study. CPP records were linked to the National Death Index and the Social Security Death Master File to identify deaths and underlying cause (until 2016). Pregnancy loss comprised self-reported losses, including abortions, stillbirths, and ectopic pregnancies. Among 48,188 women (46.0% White, 45.8% Black, 8.2% other race/ethnicity), 25.6% reported at least 1 pregnancy loss and 39% died. Pregnancy loss was associated with a higher absolute risk of all-cause mortality (risk difference, 4.0 per 100 women, 95% confidence interval: 1.4, 6.5) and cardiovascular mortality (risk difference, 2.2 per 100 women, 95% confidence interval: 0.8, 3.5). Stratified by race/ethnicity, a higher risk of mortality persisted in White, but not Black, women. Women with recurrent losses are at increased risk of death, both overall and across all race/ethnicity groups. Pregnancy loss is associated with death; however, it does not confer an excess risk above the observed baseline risk in Black women. These findings support the need to assess reproductive history as part of routine screening in women.

BACKGROUND: Caffeine is the most frequently used psychoactive substance in the United States and >90% of reproductive-age women report some amount of intake daily. Despite biological plausibility, previous studies on caffeine and fecundability report conflicting results. Importantly, prior studies measured caffeine exposure exclusively by self-report, which is subject to measurement error and does not account for factors that influence caffeine metabolism. OBJECTIVES: Our objective was to examine associations between preconception serum caffeine metabolites, caffeinated beverage intake, and fecundability. METHODS: Participants included 1228 women aged 18–40 y with a history of 1–2 pregnancy losses in the EAGeR (Effects of Aspirin in Gestation and Reproduction) trial. We prospectively evaluated associations of preconception caffeine metabolites (i.e., caffeine, paraxanthine, and theobromine) measured from 1191 serum samples untimed to a specific time of day, self-reported usual caffeinated beverage intakes at baseline, and time-varying cycle-average caffeinated beverage intake, with fecundability. Using Cox proportional hazards models, we estimated fecundability odds ratios (FORs) and 95% CIs according to each metabolite. Follow-up was complete for 89% (n = 1088) of participants. RESULTS: At baseline, 85%, 73%, and 91% of women had detectable serum caffeine, paraxanthine, and theobromine, respectively. A total of 797 women became pregnant during ≤6 cycles of preconception follow-up. After adjusting for potential confounders, neither serum caffeine [tertile (T)3 compared with T1 FOR: 0.87; 95% CI: 0.71, 1.08], paraxanthine (T3 compared with T1 FOR: 0.92; 95% CI: 0.75, 1.14), nor theobromine (T3 compared with T1 FOR: 1.15; 95% CI: 0.95, 1.40) were associated with fecundability. Baseline intake of total caffeinated beverages was not associated with fecundability (>3 compared with 0 servings/d adjusted FOR: 0.99; 95% CI: 0.74, 1.34), nor was caffeinated coffee (>2 compared with 0 servings/d adjusted FOR: 0.93; 95% CI: 0.45, 1.92) or caffeinated soda (>2 servings/d adjusted FOR: 0.92; 95% CI: 0.71, 1.20). CONCLUSIONS: Our findings are reassuring that caffeine exposure from usual low to moderate caffeinated beverage intake likely does not influence fecundability. This trial was registered at clinicaltrials.gov as NCT00467363.

To examine the relationship of preconception hemoglobin A1c, a marker of cumulative exposure to glucose over the preceding 2-3 months, with time to pregnancy, pregnancy loss, and live birth among fecund women without diagnosed diabetes or other medical diseases.A secondary analysis of a prospective cohort of women participating in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial.Four US academic medical centers.A total of 1,194 healthy women aged 18-40 years with a history of one or two pregnancy losses attempting spontaneous conception were observed for up to six cycles while attempting pregnancy and throughout pregnancy if they conceived.Not applicable.Time to pregnancy, human chorionic gonadotropin pregnancy, clinical pregnancy, pregnancy loss, and live birth.Although increasing preconception A1c level was associated with reduced fecundability (fecundability odds ratio [FOR] per unit increase in A1c 0.74; 95% confidence interval [CI] 0.57, 0.96) in unadjusted models and models adjusted for age, race, smoking and treatment arm (FOR 0.79; 95% CI 0.60, 1.04), results were attenuated after further adjustment for body mass index (FOR 0.91; 95% CI 0.68, 1.21). Preconception A1c levels among women without diagnosed diabetes were not associated with live birth or pregnancy loss.Among healthy women without diagnosed diabetes, we observed no association of A1c with live birth or pregnancy loss. The association between A1c and fecundability was influenced by body mass index, a strong risk factor for both diabetes and infertility. These data support current recommendations that preconception A1c screening should be reserved for patients with risk factors for diabetes.ClinicalTrials.gov: NCT00467363.