Frozen autologous and donor oocytes are associated with differences in clinical and neonatal outcomes compared with fresh oocytes: a Society for Assisted Reproductive Technology Clinic Outcome Reporting System Analysis.

Objective: To study the clinical and neonatal outcomes of embryos derived from frozen oocytes relative to fresh oocytes in both autologous and donor oocyte cycles after fresh embryo transfer (ET). Design: This is a retrospective cohort study using the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database between 2014 and 2015. Setting: The Society for Assisted Reproductive Technology Clinic Outcome Reporting System database was used to identify autologous and donor oocyte cycles that resulted in a fresh ET during 2014 and 2015. Patients: There were 154,706 total cycles identified that used embryos derived from fresh or frozen oocytes and resulted in a fresh ET, including 139,734 autologous oocyte cycles and 14,972 donor oocyte cycles. Interventions: Generalized linear regression models were used to compare the clinical and neonatal outcomes of frozen oocytes relative to fresh oocytes. Models were adjusted for maternal age, body mass index, smoking status, parity, infertility diagnosis, number of embryos transferred, and preimplantation genetic testing. An additional sensitivity analysis was performed to examine singleton pregnancies separately. Main Outcome Measures: The live birth (LB) rate was the primary outcome. Secondary outcomes include pregnancy and birthweight outcomes. Results: Differences in clinical and neonatal outcomes between fresh and frozen-thawed oocytes after fresh ET were observed. Specifically, our study found a higher incidence of high-birthweight infants after the use of frozen oocytes relative to fresh oocytes in both autologous oocytes (12.5% [frozen] vs. 4.5% [fresh], adjusted risk ratio [aRR] 2.67, 95% confidence interval [CI] 1.65-4.3) and donor oocyte cycles (6.2% [frozen] vs. 4.6% [fresh], aRR 1.42, 95% CI 1.1-1.83). This finding remained true when the analysis was restricted to singleton gestations only for both groups: autologous (17.3% [frozen] vs. 7.1% [fresh], aRR 2.77, 95% CI 1.74-4.42) and donor oocytes (9.4% [frozen] vs. 7.8% [fresh], aRR 1.38, 95% CI 1.07-1.77). Additionally, we observed a decrease in LB (aRR 0.81, 95% CI 0.77-0.85); clinical pregnancy (aRR 0.83, 95% CI 0.8-0.87); and an increase in biochemical pregnancy loss (aRR 1.22, 95% CI 1.05-1.43) after the use of frozen oocytes in donors, but not autologous cycles. Conclusions: Our findings of an increased incidence of high-birthweight infants after the transfer of embryos derived from frozen oocytes in both autologous and donor oocyte cycles raise questions about oocyte vitrification and deserve further study. Additionally, the finding of a decreased likelihood of LB with frozen-donor oocytes compared with fresh donor oocytes is an important finding, especially because more patients are seeking to use frozen oocytes in their donor egg cycles. Future research should be directed toward these findings to optimize the use of frozen oocytes in clinical practice.

Similar pregnancy outcomes from fresh and frozen donor oocytes transferred to gestational carriers: a SART database analysis isolating the effects of oocyte vitrification.

PURPOSE: This work aimed to study clinical and neonatal outcomes of embryos derived from frozen compared to fresh donor oocytes in gestational carrier cycles. METHODS: This is a retrospective cohort study using the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database between 2014 and 2015, comprising of 1284 fresh transfer cycles to gestational carrier recipients of embryos resulting from fresh (n = 1119) and vitrified/thawed (n = 165) donor oocytes. Models were adjusted for gestational carrier age, preimplantation genetic testing (PGT-A), number of embryos transferred, multiple gestation, and fetal heart reduction. As our models were part of a larger analysis, intended parent BMI, smoking status, and parity were also adjusted for, but did not influence outcomes in this analysis. RESULTS: There was no significant difference in probability of live birth rates when comparing embryos derived from fresh and frozen donor oocytes in gestational carrier cycles. There were also no significant differences in biochemical pregnancy losses or clinical miscarriage. There were no significant differences noted in low birthweight or high birthweight infants derived from fresh versus frozen donor oocyte after transfer into a gestational carrier. CONCLUSIONS: The analysis of fresh and frozen donor oocytes in gestational carrier cycles provides the opportunity to assess for a possible effect of vitrification on the oocyte by controlling for differences in the uterine environment. We observed no significant differences in live birth, pregnancy loss, low birthweight or high birthweight infants when comparing fresh and frozen donor oocytes in gestational carrier cycles.

Intake of Energy Drinks Before and During Pregnancy and Adverse Pregnancy Outcomes.

Importance: Consumption of energy drinks has increased drastically in recent years, particularly among young people. It is unknown whether intake of energy drinks is associated with health during pregnancy. Objective: To examine associations of energy drink intake before and during pregnancy with risk of adverse pregnancy outcomes (APOs). Design, Setting, and Participants: This prospective cohort study included data from women enrolled in the Nurses' Health Study 3 (NHS3) between June 1, 2010, and September 27, 2021, and the Growing Up Today Study (GUTS) who reported 1 or more singleton pregnancy from January 1, 2011, to June 1, 2019. Data were analyzed from October 1, 2021, to September 28, 2023. Exposure: Intake of energy drinks, assessed by food frequency questionnaire. Main Outcomes and Measures: The main outcomes were self-reported APOs, including pregnancy loss, gestational diabetes, gestational hypertension, preeclampsia, or preterm birth, and a composite APO, defined as development of any of the APOs. Risk of APOs was compared between consumers and nonconsumers of energy drinks. Results: This study included 7304 pregnancies in 4736 participants with information on prepregnancy energy drink intake and 4559 pregnancies in 4559 participants with information on energy drink intake during pregnancy. There were 1691 GUTS participants (mean [SD] age, 25.7 [2.9] years) and 3045 NHS3 participants (mean [SD] age, 30.2 [4.1] years). At baseline, 230 GUTS participants (14%) and 283 NHS3 participants (9%) reported any intake of energy drinks. While no associations were found for pregnancy loss (odds ratio [OR], 0.89; 95% CI, 0.71-1.11), preterm birth (OR, 1.07; 95% CI, 0.71-1.61), gestational diabetes (OR, 0.89; 95% CI, 0.58-1.35), preeclampsia (OR, 0.73; 95% CI, 0.41-1.30), or the composite APO (OR, 1.05; 95% CI, 0.87-1.26), prepregnancy energy drink use was associated with a higher risk of gestational hypertension (OR, 1.60; 95% CI, 1.12-2.29). A significant interaction was found between age and energy drink intake in relation to hypertensive disorders (P = .02 for interaction for gestational hypertension; P = .04 for interaction for any hypertensive disorders), with stronger associations for participants above the median age. No associations of energy drink intake during pregnancy with any of the APOs were found in NHS3 (eg, any APO: OR, 0.86; 95% CI, 0.41-1.79). Conclusions and Relevance: In this study, energy drink intake before pregnancy was associated with an elevated risk of gestational hypertension. Given the low prevalence of energy drink intake and low consumption levels among users, the results should be interpreted cautiously.

Prepregnancy Migraine, Migraine Phenotype, and Risk of Adverse Pregnancy Outcomes.

BACKGROUND AND OBJECTIVE: Migraine is a highly prevalent neurovascular disorder among reproductive-aged women. Whether migraine history and migraine phenotype might serve as clinically useful markers of obstetric risk is not clear. The primary objective of this study was to examine associations of prepregnancy migraine and migraine phenotype with risks of adverse pregnancy outcomes. METHODS: We estimated associations of self-reported physician-diagnosed migraine and migraine phenotype with adverse pregnancy outcomes in the prospective Nurses' Health Study II (1989-2009). Log-binomial and log-Poisson models with generalized estimating equations were used to estimate relative risks (RRs) and 95% CIs for gestational diabetes mellitus (GDM), preeclampsia, gestational hypertension, preterm delivery, and low birthweight. RESULTS: The analysis included 30,555 incident pregnancies after cohort enrollment among 19,694 participants without a history of cardiovascular disease, diabetes, or cancer. After adjusting for age, adiposity, and other health and behavioral factors, prepregnancy migraine (11%) was associated with higher risks of preterm delivery (RR = 1.17; 95% CI = 1.05-1.30), gestational hypertension (RR = 1.28; 95% CI = 1.11-1.48), and preeclampsia (RR = 1.40; 95% CI = 1.19-1.65) compared with no migraine. Migraine was not associated with low birthweight (RR = 0.99; 95% CI = 0.85-1.16) or GDM (RR = 1.05; 95% CI = 0.91-1.22). Risk of preeclampsia was somewhat higher among participants with migraine with aura (RR vs no migraine = 1.51; 95% CI = 1.22-1.88) than migraine without aura (RR vs no migraine = 1.30; 95% CI = 1.04-1.61; p-heterogeneity = 0.32), whereas other outcomes were similar by migraine phenotype. Participants with migraine who reported regular prepregnancy aspirin use had lower risks of preterm delivery (<2×/week RR = 1.24; 95% CI = 1.11-1.38; ≥2×/week RR = 0.55; 95% CI = 0.35-0.86; p-interaction < 0.01) and preeclampsia (<2×/week RR = 1.48; 95% CI = 1.25-1.75; ≥2×/week RR = 1.10; 95% CI = 0.62-1.96; p-interaction = 0.39); however, power for these stratified analyses was limited. DISCUSSION: Migraine history, and to a lesser extent migraine phenotype, appear to be important considerations in obstetric risk assessment and management. Future research should determine whether aspirin prophylaxis may be beneficial for preventing adverse pregnancy outcomes among pregnant individuals with a history of migraine.

The Role of Maternal Preconception Adiposity in Human Offspring Sex and Sex Ratio.

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.

Preconception sleep duration, sleep timing, and shift work in association with fecundability and live birth among women with a history of pregnancy loss.

OBJECTIVE: To evaluate the associations between preconception sleep characteristics and shift work with fecundability and live birth. DESIGN: Secondary analysis of the Effects of Aspirin in Gestation and Reproduction study, a preconception cohort. SETTING: Four US academic medical centers. PATIENT(S): Women aged 18-40 with a history of 1-2 pregnancy losses who were attempting to conceive again. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURES(S): 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. RESULT(S): Sleep duration ≥9 vs. 7 to <8 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 to <8 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. CONCLUSION(S): 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. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov NCT00467363.

Association of adverse pregnancy outcomes and multiple gestation with natural menopause: A population-based cohort study.

OBJECTIVE: Adverse pregnancy outcomes (APOs) and early menopause are each associated with increased risk of cardiovascular disease (CVD); whether APOs are associated with age at menopause is unclear. We examined the association of gestational diabetes (GDM), hypertensive disorders of pregnancy (HDP), preterm birth, and multiple gestation with age at natural menopause. STUDY DESIGN: Observational, prospective study within the Nurses' Health Study II cohort (1989-2019). MAIN OUTCOMES MEASURES: Risk of early natural menopause, defined as occurring before the age of 45 years, and age at onset of natural menopause (hazard ratio (HR) >1 indicates younger age at menopause). RESULTS: The mean [SD] baseline age of 69,880 parous participants was 34.5 [4.7] years. Compared with participants who had a term singleton first birth, those with a term multiple-gestation first birth had higher risk of early menopause (HR: 1.65, 95% CI: 1.05, 2.60) and younger age at natural menopause (HR: 1.46, 95% CI: 1.31, 1.63). Estimates for preterm multiple gestation were of similar magnitude. Menopause occurred at a younger age for those with a preterm birth with spontaneous labor (HR: 1.08, 95% CI: 1.03, 1.14) compared to those with a term birth with spontaneous labor. Conversely, estimates for GDM (HR: 0.95, 95% CI: 0.89, 1.02) and HDP (preeclampsia, HR: 0.93, 95% CI: 0.89, 0.97) suggested an association with older age at menopause. CONCLUSIONS: In this large cohort study, several statistically significant associations between APOs and age at natural menopause were observed. A deeper understanding of the relationships among APOs, menopause, and CVD is needed to help identify people at higher risk for early menopause and later CVD.

Prospectively assessed perceived stress associated with early pregnancy losses among women with history of pregnancy loss.

STUDY QUESTION: What is the association between perceived stress during peri-conception and early pregnancy and pregnancy loss among women who have experienced a prior pregnancy loss? SUMMARY ANSWER: Daily perceived stress above the median is associated with over a 2-fold risk of early pregnancy loss among women who have experienced a prior loss. WHAT IS KNOWN ALREADY?: Women who have experienced a pregnancy loss may be more vulnerable to stress while trying to become pregnant again. While prior research has indicated a link between psychological stress and clinically confirmed miscarriages, research is lacking among a pre-conceptional cohort followed prospectively for the effects of perceived stress during early critical windows of pregnancy establishment on risk of both hCG-detected pregnancy losses and confirmed losses, while considering important time-varying confounders. STUDY DESIGN, SIZE, DURATION: Secondary data analysis of the EAGeR trial (2007-2011) among women with an hCG-detected pregnancy (n = 797 women). PARTICIPANTS/MATERIALS, SETTING, METHODS: Women from four US clinical centers enrolled pre-conceptionally and were followed ≤6 cycles while attempting pregnancy and, as applicable, throughout pregnancy. Perceived stress was captured via daily diaries and end-of-month questionnaires. Main outcome measures include hCG-detected and clinically recognized pregnancy losses. MAIN RESULTS AND THE ROLE OF CHANCE: Among women who had an hCG-confirmed pregnancy, 188 pregnancies (23.6%) ended in loss. Women with high (>50th percentile) versus low (≤50th percentile) peri-implantation or early pregnancy weekly perceived stress had an elevated risk of experiencing any pregnancy loss (hazard ratio (HR): 1.69, 95% CI: 1.13, 2.54) or clinical loss (HR: 1.58, 95% CI: 0.96, 2.60), with higher risks observed for women experiencing an hCG-detected loss (HR: 2.16, 95% CI: 1.04, 4.46). Models accounted for women's age, BMI, employment, marital status, income, education, race, parity, prior losses, exercise and time-varying nausea/vomiting, caffeine, alcohol and smoking. LIMITATIONS, REASONS FOR CAUTION: We were limited in our ability to clearly identify the mechanisms of stress on pregnancy loss due to our sole reliance on self-reported perceived stress, and the lack of biomarkers of different pathways of stress. WIDER IMPLICATIONS OF THE FINDINGS: This study provides new insight on early pregnancy perceived stress and risk of pregnancy loss, most notably hCG-detected losses, among women with a history of a prior loss. Our study is an improvement over past studies in its ability to account for time-varying early pregnancy symptoms, such as nausea/vomiting, and lifestyle factors, such as caffeine, alcohol and smoking, which are also risk factors for psychological stress and pregnancy loss. STUDY FUNDING/COMPETING INTEREST(S): This work 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 numbers: HHSN267200603423, HHSN267200603424, HHSN267200603426, HHSN275201300023I). Additionally, K.C.S. was supported by the National Institute on Aging of the National Institutes of Health under Award Number K01AG058781. The authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: #NCT00467363.

The association between anthropometric factors and anti-Müllerian hormone levels in premenopausal women.

Adiposity has been associated with several health conditions as well as timing of menopause. Prior epidemiologic studies on the association of adiposity and anti-Müllerian hormone (AMH) have been inconsistent. We evaluated the relations of anthropometric measures with AMH at two time periods in a subset of premenopausal participants in the Nurses' Health Study II. This prospective study included 795 women who provided a premenopausal sample in 1996-1999 and in 2010-2012. Current weight and height, and weight at age 18 were assessed in 1989 and weight again in 1996-1999. Waist and hip circumference were measured and reported in 1993. In linear regression models adjusted for smoking, reproductive events, and other factors, AMH was inversely related to BMI at age 18 (P = .03) and in 1996-1999 (P < .0001). Higher waist circumference was related to lower AMH levels in 1996-1999 (p = .0009). BMI in 1996-1999 was inversely associated with AMH levels in 2010-2012 (P = .005). Weight gain between age 18 and 1996-1999 was strongly inversely associated with AMH levels in 1996-1999 (P < .0001) and in 2010-2012 (P < .0001). Our results indicate that adiposity and weight gain are associated with lower AMH levels, suggesting an adverse impact on ovarian function.

Association of In Utero Exposures With Risk of Early Natural Menopause.

Suboptimal pregnancy conditions may affect ovarian development in the fetus and be associated with early natural menopause (ENM) for offspring. A total of 106,633 premenopausal participants in Nurses' Health Study II who provided data on their own prenatal characteristics, including diethylstilbestrol (DES) exposure, maternal cigarette smoking exposure, multiplicity, prematurity, and birth weight, were followed from 1989 to 2017. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of in utero exposures with ENM. During 1.6 million person-years of follow-up, 2,579 participants experienced ENM. In multivariable models, women with prenatal DES exposure had higher risk of ENM compared with those without it (HR = 1.33, 95% CI: 1.06, 1.67). Increased risk of ENM was observed for those with low (<5.5 pounds (<2.5 kg)) versus normal (7.0-8.4 pounds (3.2-3.8 kg)) birth weight (HR = 1.21, 95% CI: 1.01, 1.45). Decreasing risk was observed per 1-pound (0.45-kg) increase in birth weight (HR = 0.93, 95% CI: 0.90, 0.97). Prenatal smoking exposure, being part of a multiple birth, and prematurity were not associated with ENM. In this large cohort study, lower birth weight and prenatal DES exposure were associated with higher risk of ENM. Our results support a need for future research to examine in utero exposures that may affect offspring reproductive health.

Preconception caffeine metabolites, caffeinated beverage intake, and fecundability.

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.

Maternal caffeine intake and DNA methylation in newborn cord blood.

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. OBJECTIVES: We examined preconception and pregnancy caffeine exposure with DNAm alterations in neonate cord blood (n = 378). METHODS: 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 ß 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 1 or fewer servings/day of caffeine on average, and caffeine and paraxanthine metabolite levels were 88 and 36 µmol/L, respectively. Preconception serum caffeine metabolites were not associated with individual cytosine-guanine (CpG) sites (FDR >5%), though pregnancy theobromine was associated with DNAm at cg09460369 near RAB2A (ß = 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 (ß = -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 population with relatively low caffeine consumption.

Iodine and thyroid status during pregnancy and risk of stillbirth: A population-based nested case-control study.

Prior research suggests that severe iodine deficiency in pregnancy may be associated with stillbirth. However, the relationship between mild to moderate iodine insufficiency, which is prevalent even in developed countries, and risk of stillbirth is unclear. We thus examined associations of iodine status and risk of stillbirth in a prospective population-based nested case-control study in Finland, a mild to moderately iodine insufficient population. Stillbirth cases (n = 199) and unaffected controls (n = 249) were randomly selected from among all singleton births in Finland from 2012 to 2013. Serum samples were collected between 10 and 14 weeks gestation and analysed for iodide, thyroglobulin (Tg) and thyroid-stimulating hormone (TSH). Odds ratios (ORs) and 95% confidence intervals (CIs) for stillbirth were estimated using logistic regression. After adjusting for maternal age, prepregnancy body mass index, socio-economic status and other factors, neither high nor low serum iodide was associated with risk of stillbirth (Q1 vs. Q2-Q3 OR = 0.92, 95% CI = 0.78-1.09; Q4 vs. Q2-Q3 OR = 0.78; 95% CI = 0.45-1.33). Tg and TSH were also not associated with risk of stillbirth in adjusted models. Maternal iodine status was not associated with stillbirth risk in this mildly to moderately iodine-deficient population. Tg and TSH, which reflect functional iodine status, were also not associated with stillbirth risk. The lack of associations observed between serum iodide, TSH and Tg and risk of stillbirth is reassuring, given that iodine deficiency in pregnancy is prevalent in developed countries.

The association of parity and breastfeeding with anti-Müllerian hormone levels at two time points.

OBJECTIVE: To evaluate the association between parity and breastfeeding and anti-Müllerian hormone levels (AMH) and change in AMH levels over time. Furthermore, we examined whether AMH levels mediate the relation of parity and breastfeeding with age at menopause. STUDY DESIGN: Observational, prospective cohort study. MAIN OUTCOME MEASURES: AMH levels were assessed in a subset of premenopausal participants in the Nurses' Health Study II, including 1619 women who provided a blood sample in 1996-1999 and an additional 800 women who provided a second premenopausal sample in 2010-2012. RESULTS: In multivariable linear regression models adjusted for parity, body mass index, smoking, and other factors, mean log AMH levels in 1996-1999 were 39% higher in women reporting ≥25 months of total breastfeeding vs. <1 month (P for trend = 0.009). Parity was not associated with AMH levels after adjustment for breastfeeding. Neither parity nor breastfeeding was associated with decline in AMH levels over 11 to 15 years. Breastfeeding duration was positively associated with age at menopause (P for trend = 0.01), with evidence that the association was mediated via AMH. CONCLUSIONS: Our results suggest that breastfeeding is associated with higher AMH levels and later onset of menopause, and support the hypothesis that observed relations of parity with AMH levels and menopause timing may be largely attributable to breastfeeding.

Association of oral contraceptives and tubal ligation with antimüllerian hormone.

OBJECTIVE: Oral contraceptives (OCs) and tubal ligation are commonly used methods of contraception that may impact ovarian function. Few studies have examined the association of these factors with antimüllerian hormone (AMH), a marker of ovarian aging. METHODS: We examined the association of OC use and tubal ligation with AMH in the Nurses' Health Study II prospective cohort among a subset of 1,420 premenopausal participants who provided a blood sample in 1996-1999. History of OC use and tubal ligation were reported in 1989 and updated every 2 years until blood collection. We utilized generalized linear models to assess whether mean AMH levels varied by duration of and age at first use of OCs and history, age, and type of tubal ligation. RESULTS: In multivariable models adjusted for smoking, reproductive events, and other lifestyle factors, we observed a significant, inverse association between duration of OC use and mean AMH levels (P for trend = 0.036). Compared to women without a tubal ligation, AMH levels were significantly lower when the procedure included a clip, ring, or band (1.04 ng/ml vs 1.72 ng/ml, P < 0.01). AMH levels were not associated with age at first use of OCs or age at tubal ligation. CONCLUSIONS: Our analysis found an association between duration of OC use and certain types of tubal ligation with mean AMH levels. Further research is warranted to confirm the long-term association of these widely used contraceptive methods with AMH.

Video Summary:http://links.lww.com/MENO/A860 .

Preconception leukocyte telomere length and pregnancy outcomes among women with demonstrated fecundity.

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.

Is Alcohol Consumption Associated With Risk of Early Menopause?

Earlier age at menopause is associated with increased long-term health risks. Moderate alcohol intake has been suggested to delay menopause onset, but it is unknown whether alcohol subtypes are associated with early menopause onset at age 45 years. Therefore, we aimed to evaluate risk of early natural menopause among 107,817 members of the Nurses' Health Study II who were followed from 1989 to 2011. Alcohol consumption overall and by subtypes, including beer, red wine, white wine, and liquor, was assessed throughout follow-up. We estimated hazard ratios in multivariable models that were adjusted for age, body mass index, parity, smoking, and other potential confounders. Women who reported moderate current alcohol consumption had lower risks of early menopause than did nondrinkers. Those who reported consuming 10.0-14.9 g/day had a lower risk of early menopause than did nondrinkers (hazard ratio = 0.81, 95% confidence interval: 0.68, 0.97). Among specific beverages, evidence of lower early menopause risk was confined to consumption of white wine and potentially red wine and liquor, but not to beer. Data from this large prospective study suggest a weak association of moderate alcohol intake with lower risk of early menopause, which was most pronounced for consumption of white and red wine and liquor. High consumption was not related to lower risk of early menopause.

The role of maternal preconception vitamin D status in human offspring sex ratio.

Evolutionary theory suggests that some animal species may experience shifts in their offspring sex ratio in response to maternal health and environmental conditions, and in some unfavorable conditions, females may be less likely to bear sons. Experimental data in both animals and humans indicate that maternal inflammation may disproportionately impact the viability of male conceptuses; however, it is unknown whether other factors associated with both pregnancy and inflammation, such as vitamin D status, are associated with the offspring sex ratio. Here, we show that among 1,228 women attempting pregnancy, preconception 25-hydroxyvitamin D concentrations are positively associated with the live birth of a male infant, with notably stronger associations among women with elevated high sensitivity C-reactive protein, a marker of systemic low-grade inflammation. Our findings suggest that vitamin D may mitigate maternal inflammation that would otherwise be detrimental to the implantation or survival of male conceptuses in utero.

The Joint Role of Iodine Status and Thyroid Function on Risk for Preeclampsia in Finnish Women: a Population-Based Nested Case-Control Study.

Preeclampsia, a pregnancy disorder that includes hypertension and proteinuria, is a major cause of maternal and fetal morbidity and mortality. Some studies, but not all, have found that women with preeclampsia have significantly lower iodine levels than healthy pregnant women. Resolving this issue is important because iodine deficiency in pregnancy is common in the USA and parts of Europe including Finland. We conducted a nested case-control study to determine whether the risk for preeclampsia is associated with iodine status. We measured serum iodine, thyroglobulin (Tg), and thyroid stimulating hormone (TSH) at 10-14 weeks gestational age in 204 women with preeclampsia and 246 unaffected controls selected from all births in Finland. We found no significant difference in iodine (case mean = 26.04 ng/mL, control mean = 27.88 ng/mL, p = 0.995), Tg (case mean = 31.11 ng/mL, control mean = 29.61 ng/mL, p = 0.996), and TSH (case mean = 1.30 mIU/L, control mean = 1.24 mIU/L, p = 0.896) levels between cases and controls. There was no significant relationship between preeclampsia risk and iodine, Tg, or TSH after adjustment for known risk factors. These results are reassuring given the high prevalence of iodine deficiency in pregnancy.