Folic acid supplement use and menstrual cycle characteristics: a cross-sectional study of Danish pregnancy planners.

Purpose: To examine the association between folic acid (FA) supplementation obtained through either single FA tablets or multivitamins (MVs) and menstrual cycle characteristics among 5386 women aged 18-40 years, enrolled in an Internet-based study of Danish women attempting pregnancy during 2007-2011.

Methods: In a cross-sectional study, we used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of FA supplementation with menstrual cycle regularity; short (<27 days), long (30-33 days), and very long (≥34 days) cycle lengths; and duration and intensity of menstrual bleeding.

Results: Compared with nonuse, FA supplementation was associated with reduced odds of short cycle length (OR = 0.

Design and Conduct of an Internet-Based Preconception Cohort Study in North America: Pregnancy Study Online.

Background: We launched the Boston University Pregnancy Study Online (PRESTO) to assess the feasibility of carrying out an Internet-based preconception cohort study in the US and Canada.

Methods: We recruited female participants age 21-45 and their male partners through Internet advertisements, word of mouth, and flyers. Female participants were randomised with 50% probability to receive a subscription to FertilityFriend.

Pre-gravid oral contraceptive use in relation to birth weight: a prospective cohort study.

Few studies have evaluated the association between pregravid oral contraceptive (OC) use and birth weight, and findings have been conflicting. We conducted a prospective cohort study of 5921 pregnancy planners in Denmark to evaluate recency, duration, and type of OC used before conception in relation to infant birth weight. Participants completed online questionnaires and reported detailed information on contraceptive history and covariates at baseline.

Lactation in Relation to Long-Term Maternal Weight Gain in African-American Women.

We assessed the relationship of lactation to long-term maternal weight gain among African-American women, who have a lower prevalence of lactation and a higher prevalence of obesity than other US women. A pregnancy cohort of 3,147 African-American women from the Black Women's Health Study who gave birth for the first time between 1995 and 2003 was followed for 8 years postpartum. Participants provided data on weight, lactation, gestational weight gain, education, diet, and exercise.

Stressful events during pregnancy and postpartum depressive symptoms.

Background: Understanding the influence of perinatal stressors on the prevalence of postpartum depressive symptoms (PDS) and help-seeking for PDS using surveillance data can inform service provision and improve health outcomes.

Methods: We used Massachusetts Pregnancy Risk Assessment Monitoring System (MA-PRAMS) 2007-2010 data to evaluate associations between selected perinatal stressors and PDS and with subsequent help-seeking behaviors. We categorized 12 stressors into 4 groups: partner, traumatic, financial, and emotional.

Long-chain ω-3 fatty acid intake and endometrial cancer risk in the Women's Health Initiative.

Background: Inflammation may be important in endometrial cancer development. Long-chain ω-3 (n-3) polyunsaturated fatty acids (LCω-3PUFAs) may reduce inflammation and, therefore, reduce cancer risk. Because body mass is associated with both inflammation and endometrial cancer risk, it may modify the association of fat intake on risk.

Prospective study of time to pregnancy and adverse birth outcomes.

Objective: To investigate the association between time to pregnancy (TTP) and adverse birth outcomes.

Design: Prospective cohort study.

Setting: Not applicable.

Night-shift work and incident diabetes among African-American women.

Aims/hypothesis: The aim of this study was to assess shift work in relation to incident type 2 diabetes in African-American women.

Methods: In the Black Women's Health Study (BWHS), an ongoing prospective cohort study, we followed 28,041 participants for incident diabetes during 2005-2013. They answered questions in 2005 about having worked a night shift.

Depressive symptoms and risk of uterine leiomyomata.

Objective: Uterine leiomyomata (UL) are a major source of gynecologic morbidity and the primary indication for hysterectomy. Depression can cause dysregulation of the hypothalamic-pituitary-adrenal axis, which may affect the synthesis of reproductive hormones involved in UL pathogenesis. We assessed the association between depressive symptoms and UL among 15,963 premenopausal women.

Intrauterine devices and endometrial cancer risk: a pooled analysis of the Epidemiology of Endometrial Cancer Consortium.

Intrauterine devices (IUDs), long-acting and reversible contraceptives, induce a number of immunological and biochemical changes in the uterine environment that could affect endometrial cancer (EC) risk. We addressed this relationship through a pooled analysis of data collected in the Epidemiology of Endometrial Cancer Consortium. We combined individual-level data from 4 cohort and 14 case-control studies, in total 8,801 EC cases and 15,357 controls.

Body size and risk of spontaneous abortion among danish pregnancy planners.

Background: Several studies indicate that female obesity increases the risk of spontaneous abortion (SAB). Central adiposity, height, and location of typical weight gain have not been examined as risk factors for SAB.

Methods: We examined the associations between selected anthropometric factors and risk of SAB among 5132 women enrolled in a Danish Internet-based prospective cohort study of pregnancy planners.

Preterm birth and subsequent risk of type 2 diabetes in black women.

Background: Gestational diabetes is a precursor to type 2 diabetes. Little is known about the relation of other common pregnancy complications, such as preterm birth, to risk of type 2 diabetes.

Methods: We assessed preterm birth in relation to incident type 2 diabetes among 31,101 participants from the Black Women's Health Study.

Birth weight and risk of type 2 diabetes in the black women's health study: does adult BMI play a mediating role?

Objective: To assess the association of birth weight with incident type 2 diabetes, and the possible mediating influence of obesity, in a large cohort of U.S. black women.

Polymorphisms in vitamin D-related genes and risk of uterine leiomyomata.

Objective: To investigate uterine leiomyomata (UL) incidence in relation to polymorphisms in genes involved in vitamin D metabolism and skin pigmentation. Rates of UL are 2-3 times higher in African Americans than in European Americans. Recent studies suggest that vitamin D deficiency is associated with an increased risk of UL.

Depressive symptoms, antidepressant use, and the incidence of diabetes in the Black Women's Health Study.

Objective: To assess the relationship of depressive symptoms and use of antidepressants with incident type 2 diabetes in prospective data from a large cohort of U.S. African American women.

Active and passive smoking and fecundability in Danish pregnancy planners.

Objective: To investigate the extent to which fecundability is associated with active smoking, time since smoking cessation, and passive smoking.

Design: Prospective cohort study.

Setting: Denmark, 2007-2011.

Weight at birth and subsequent fecundability: a prospective cohort study.

Objective: To examine the association between a woman's birth weight and her subsequent fecundability.

Method: In this prospective cohort study, we included 2,773 Danish pregnancy planners enrolled in the internet-based cohort study "Snart-Gravid", conducted during 2007-2012. Participants were 18-40 years old at study entry, attempting to conceive, and were not receiving fertility treatment.

Prospective study of dietary fat and risk of uterine leiomyomata.

Background: Uterine leiomyomata (UL) are the primary indication for hysterectomy and are 2-3 times more common in black than white women. High dietary fat intake has been associated with increased endogenous concentrations of estradiol, a sex steroid hormone that is known to influence UL risk.

Objective: We assessed the relation of dietary fat intake (total, subtypes, and selected food sources) with UL incidence.

Menarche, menopause, years of menstruation, and the incidence of osteoporosis: the influence of prenatal exposure to diethylstilbestrol.

Context: Estrogen is critical for bone formation and growth in women. Estrogen exposures occur throughout life, including prenatally, and change with reproductive events, such as menarche and menopause.

Objective: The objective of this study was to investigate the association between age at menarche, age at menopause, and years of menstruation with incidence of osteoporosis and assess the impact of prenatal exposure to diethylstilbestrol (DES), a synthetic estrogen, on such associations.

Prenatal diethylstilbestrol exposure and risk of uterine leiomyomata in the Nurses' Health Study II.

Previous studies evaluating the association of prenatal exposure to diethylstilbestrol (DES), a potent endocrine disruptor, with incidence of uterine leiomyomata (UL) have had conflicting results. We evaluated the association between prenatal DES exposure and incident UL in women in the Nurses' Health Study II from 1989 to 2009. Women were aged 25-42 years at enrollment and had a prenatal exposure window corresponding to DES use.

A prospective study of smoking and breast cancer risk among African-American women.

Purpose: Active smoking and passive smoking have been associated with increased risk of breast cancer. The purpose of the present study was to prospectively assess associations of smoking with breast cancer and identify subgroups at higher risk among African-American women.

Methods: Based on 1,377 incident cases identified during 14 years of follow-up in the Black Women's Health Study, we assessed active and passive smoking in relation to breast cancer incidence by menopausal status, estrogen receptor status, and other factors.

Correlates of menstrual cycle characteristics among nulliparous Danish women.

Objective: We examined the association between lifestyle factors and menstrual cycle characteristics among nulliparous Danish women aged 18-40 years who were participating in an Internet-based prospective cohort study of pregnancy planners.

Methods: We used cross-sectional data collected at baseline to assess the association of age, body mass index (BMI), physical activity, alcohol and caffeine consumption, and smoking with the prevalence of irregular cycles, short (≤25 days) and long (≥33 days) cycles, and duration and amount of menstrual flow. We used log-binomial and multinomial logistic regression to estimate prevalence ratios and 95% confidence intervals.

Body size and time-to-pregnancy in black women.

Study Question: Are overall and central obesity associated with reduced fecundability in US black women?

Summary Answer: Overall and central obesity--based on self-reported measures of body mass index (BMI, kg/m(2)), waist circumference and waist-to-hip ratio--were independent risk factors for subfertility in our cohort.

What Is Known Already: Overall obesity (BMI ≥ 30 kg/m(2)) has been associated with infertility in several studies. The role of central obesity is less clear.

Is the observed association between dairy intake and fibroids in African Americans explained by genetic ancestry?

Uterine leiomyomata are a major source of gynecological morbidity and are 2-3 times more prevalent in African Americans than European Americans. In an earlier report, we found that dairy intake was inversely associated with uterine leiomyomata among African Americans. Because African Americans are more likely to have lactose intolerance and avoid dairy products, the observed association might have been confounded by genetic ancestry.