Germaine M. Buck Louis

George Mason University | GMU · College of Health and Human Services

Twin gestations have greater nutritional demands than singleton gestations, yet dietary intakes of women with twin gestations have not been well described. In a prospective, multi-site US study of 148 women with dichorionic twin gestations (2012–2013), we examined longitudinal changes in diet across pregnancy. Women completed a food frequency quest...

Background: Fibroids (hormonally responsive benign tumors) often undergo volume changes in pregnancy. Because per- and polyfluoroalkyl substances (PFAS) disrupt hormonal signaling, they might affect fibroid growth. We assessed associations between PFAS and fibroid changes in pregnancy. Methods: We analyzed seven PFAS, including perfluorohexanesu...

Purpose: To investigate the relationship of fibroids in pregnancy, preterm birth, and neonatal anthropometry. Methods: Pregnant women (n=2,578) in the NICHD Fetal Growth Studies - Singletons cohort had up to 6 ultrasounds across pregnancy. Sonographers recorded fibroid number and volume of the 3 largest fibroids. Trained personnel measured neona...

Objective To describe the natural history of fibroids in pregnancy in a racially diverse cohort and explore whether fibroid changes were associated with participant characteristics. Design Prospective cohort study. Setting Twelve clinical sites. Patient(s) Pregnant women (n = 2774; 27% non-Hispanic White, 28% non-Hispanic Black, 29% Hispanic, 17...

Urinary concentrations of several endocrine disrupting chemicals, including phthalate metabolites, bisphenol A (BPA), and benzophenone (BP)-type ultraviolet (UV) filters, have been associated with a longer time-to-pregnancy (TTP). Potential modification of these associations by couple’s age has not been studied. TTP was defined as the number of pro...

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 chro...

Background: Women with endometriosis may have an increased risk of adverse pregnancy outcomes. Research has focused on infertility clinic populations limiting generalisability. Few studies report differences by endometriosis severity. Objectives: We investigated the relationships between endometriosis diagnosis, staging and typology and pregnanc...

Introduction: Exercise in pregnancy is associated with many perinatal benefits, but patterns of home, work, and commuting activity are not well described. We investigated longitudinal activity in singleton and twin pregnancy by activity domain and maternal characteristics. Methods: In the NICHD Fetal Growth Studies cohorts, 2778 women with singl...

Background A few endocrine disrupting chemicals (EDCs) have been associated with pregnancy loss often as reported by women, though there has been no study of EDC mixtures and pregnancy loss in keeping with the nature of human exposure. Objectives To investigate preconception exposure to a mixture of EDCs to identify important drivers and inform mu...

Understanding implications of passive smoke exposure during pregnancy is an important public health issue under the Developmental Origins of Health and Disease paradigm. In a prospective cohort of low-risk non-smoking pregnant women (NICHD Fetal Growth Studies—Singletons, 2009–2013, N = 2055), the association between first trimester passive smoke e...

Multiple studies have demonstrated a global population-wide decline in semen quality, with sperm concentrations having fallen 50% over the past 50 years. Several metal and metalloid ("metal(loid)") compounds are known to have testicular toxicity, raising concerns about their contribution to rising infertility. In the male reproductive tract, metal(...

Importance Higher caffeine consumption during pregnancy has been associated with lower birth weight. However, associations of caffeine consumption, based on both plasma concentrations of caffeine and its metabolites, and self-reported caffeinated beverage intake, with multiple measures of neonatal anthropometry, have yet to be examined. Objective...

FutureTox IV, a Society of Toxicology (SOT) Contemporary Concepts in Toxicology (CCT) workshop, was held in November 2018. Building upon FutureTox I, II, and III, this conference focused on the latest science and technology for in vitro profiling and in silico modeling as it relates to predictive developmental and reproductive toxicity (DART). Publ...

Background Endometriosis is an estrogen-dependent disease. Endocrine disrupting chemicals (EDCs) and their mixtures may play an etiologic role. Objectives We evaluated an adipose-to-serum ratio (ASR) of lipophilic EDCs and their mixtures associated with incident endometriosis. Methods We quantified 13 polychlorinated biphenyl (PCB) congeners, 6 p...

Background Accumulating evidence indicates that maternal diets are important for optimizing maternal and offspring health. Existing research lacks comprehensive profiles of maternal diets throughout pregnancy, especially in a racially/ethnically diverse obstetrical population. Objective To characterize diets in a longitudinal U.S. pregnancy cohort...

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: Se...

Background: Prenatal maternal plasma persistent organic pollutant (POP) concentrations have been associated with neonatal outcomes. However, the underlying mechanisms remain unknown. Placental epigenetic mechanisms may be involved, but no prior epigenome-wide studies have investigated the impact of maternal POPs on placental DNA methylation. We st...

Background The timepoint at which fetal growth begins to differ by maternal glycaemic status is not well understood. To address this lack of data, we examined gestational diabetes, impaired glucose tolerance, and early pregnancy glucose concentrations in relation to fetal growth trajectories. Methods This cohort study included 2458 pregnant women...

Study objective: Prior research collectively shows that endometriosis is inversely related to women's adiposity. The aim of this study was to assess whether this inverse relationship holds true by disease severity and typology. Design: Cross sectional study among women with no prior diagnosis of endometriosis. Setting: Fourteen clinical center...

Endometriosis is a hormone-responsive gynecologic disease, signifying its connotations across a woman's life span. Previous studies suggested that endocrine disrupting chemicals were risk factors for endometriosis. Nevertheless, little is known on exposure to organophosphate, pyrethroid and phenoxy acid pesticides on endometriosis diagnosis. In thi...

Importance Prenatal exposure to persistent organic pollutants (POPs) has been associated with birth size, but data on fetal growth and among racially/ethnically diverse pregnant women remain scarce. Objectives To assess the association between maternal plasma POPs in early pregnancy and fetal growth and by infant sex and maternal race/ethnicity....

Objective: Studies have shown that individual trace element levels might be associated with abnormal glycemic status, with implications for diabetes. Few studies have considered these trace elements as a mixture and their impact on gestational glucose levels. Comparing three statistical approaches, we assessed the associations between essential tr...

Context Phytoestrogens may influence fecundability, though biological mechanisms remain elusive. Since it is hypothesized that phytoestrogens may act through influencing hormone levels, we investigated associations between phytoestrogens and menstrual cycle length, a proxy for the hormonal milieu, in healthy women attempting pregnancy. Design A po...

In 2017, the Division of Intramural Population Health Research (DIPHR), within the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), reached a significant milestone: 50 years in existence. DIPHR celebrated this anniversary with a scientific program that reviewed past accomplishments and reflected on future dir...

Background: Prenatal exposure to persistent organic pollutants (POPs) may be associated with obesogenic effects in offspring. Our study is the first to investigate associations between concentrations of POPs from newborn dried blood spots (DBS) and birth characteristics. Methods: Concentrations of 10 polychlorinated biphenyl congeners (PCBs), po...

Background: The exposome is a novel research paradigm offering promise for understanding the complexity of human exposures, including endocrine-disrupting chemicals (EDCs) and pregnancy outcomes. The physiologically active state of pregnancy requires understanding temporal changes in EDCs to better inform the application of the exposome research p...

Background: Studies of body mass index and semen quality have reported mixed results, but almost all were cross-sectional and many were conducted in selected populations. Longitudinal studies in population-based cohorts are necessary to identify how timing and duration of excess adiposity may affect semen quality. Methods: In 193 members of the...

Background: Birthweight discordance is well studied, with less known about longitudinal inter-twin differences in foetal growth. Objective: To examine inter-twin per cent differences in EFW (EFW% ), head (HC% ) and abdominal circumference (AC% ), and femur length (FL% ) across gestation in dichorionic twin gestations and explore associated chara...

Identifying factors that influence fetal growth in a sex-specific manner can help unravel mechanisms that explain sex differences in adverse neonatal outcomes and in-utero origins of cardiovascular disease disparities. Premature aging of the placenta, a tissue that supports fetal growth and exhibits sex-specific epigenetic changes, is associated wi...

Background: Although intertwin size difference is an important measure of fetal growth, the appropriate cut point to define discordance is unclear. Few studies have assessed intertwin differences in estimated fetal weight longitudinally or in relation to size differences at birth. Objectives: The objectives of the study were to estimate the magn...

Background: A number of essential trace elements are involved in glucose metabolism, but the associations between these elements and glucose levels among pregnant women are unclear. Furthermore, little is known about the joint association of these trace elements. Methods: We used data from 1857 women enrolled in the Eunice Kennedy Shriver National...

Human exposure to persistent environmental pollutants often results in concentrations with a range of values below the laboratory detection limits. Growing evidence suggests that inadequate handling of concentrations below the limit of detection (LOD) may bias assessment of health effects in relation to environmental exposures. We seek to quantify...

Objectives: Gestational diabetes (GDM) is associated with increased risk for large-for-gestational-age birth. Yet, longitudinal fetal growth trajectories in women with GDM and the timing of alterations related to GDM is not well understood, particularly in early pregnancy. This study aims to investigate these critical data gaps. Methods: The NIC...

Context Studies suggest many essential trace metal(loid)s are involved in glucose metabolism, but the associations among pregnant women are unclear. Objective To assess associations between early pregnancy plasma zinc, selenium, copper and molybdenum and blood glucose levels later in the 2nd trimester. Design Eunice Kennedy Shriver National Insti...

Iodine deficiency in pregnancy is a common problem in the United States and parts of Europe, but whether iodine deficiency is associated with increased pregnancy loss has not been well studied. The LIFE study provided an excellent opportunity to examine the relationship between iodine status and pregnancy loss because women were monitored prospecti...

Background: Equivocal findings exist regarding prenatal acetaminophen use and various adverse neonatal and childhood health outcomes, though with no data on fetal growth. We evaluated whether fetal growth differed by maternal acetaminophen use. Methods: Racially diverse, healthy women with low-risk antenatal profiles from 12 US clinical centers...

Background: Amniotic fluid is essential to normal fetal development and is estimated clinically with ultrasound scanning to identify pregnancies that are at risk for poor perinatal outcome. Objective: Our goal was to develop a United States standard for amniotic fluid volume that is estimated by the amniotic fluid index and single deepest pocket...

Objective The goal of this study was to determine whether newborn concentrations of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and bisphenol A (BPA) are associated with early childhood growth. Methods A total of 1,954 singletons and 966 twins from the Upstate KIDS Study (born 2008‐2010) were included in this study. Newbor...

Background Endometriosis is a gynaecological disease characterized by the presence of ectopic endometrial tissue that affects women during their reproductive years, having a strong impact on their lives, fertility and healthcare costs. The aetiology remains largely unknown, but current evidence suggests that it is multi-causal and oestrogen-depend...

Objectives: Exposome-wide association studies (EWAS) are a systematic and unbiased way to investigate multiple environmental factors associated with phenotype. We applied EWAS to study semen quality and queried the sample size requirements to detect modest associations in a reproductive cohort. Study design and setting: We conducted 1) a multiva...

Retrospectively ascertained survival time may be subject to recall error. An example of discrete survival time with such recall error is time-to-pregnancy (TTP), the number of months non-contracepting couples require to get pregnant which is a measure of human fecundity. The epidemiological literature has demonstrated that retrospective TTP is subj...

Background: Caffeine, alcohol, smoking and physical activity are known to alter sex steroid synthesis, which may affect hormone-dependent gynaecologic disease risk, such as endometriosis; however, few studies have assessed life style factors prior to endometriosis diagnosis. Methods: Four hundred and seventy three women, ages 18-44 years, underw...

In epidemiological studies of environmental pollutants in relation to human infertility, it is common that concentrations of a large number of exposures are collected in both male and female partners. Such a couple‐based study poses some new challenges in statistical analysis, especially when the effect of the totality of these chemical mixtures is...

Mediation analysis assesses the effect of study exposures on an outcome both through and around specific mediators. While mediation analysis involving multiple mediators has been addressed in recent literature, the case of multiple exposures has received little attention. With the presence of multiple exposures, we consider regularizations that all...

Motivated by the Longitudinal Investigation of Fertility and the Environment (LIFE) Study that investigated the association between exposure to a large number of environmental pollutants and human reproductive outcomes, we propose a joint latent risk class modeling framework with an interaction between female and male partners of a couple. This for...

Background: Novel methodologies to quantify infant exposures to endocrine disrupting chemicals (EDCs) for population-based studies are needed. Objectives: We used newborn dried blood spots to quantify three EDCs and their associations with infant outcomes in the Upstate KIDS Cohort. Methods: We measured bisphenol A (BPA), perfluorooctanesulfon...

Background: Polybrominated diphenyl ethers (PBDEs) have not been studied in relation to incident pregnancy loss in human populations, despite their ubiquitous exposure and purported reproductive toxicity. Objectives: To investigate the association between preconception serum PBDE concentrations and incident pregnancy loss. Methods: A preconcep...

Experimental studies suggest that prenatal exposure to endocrine disrupting chemicals interferes with developmental processes in the fetal brain. Yet, epidemiological evidence is inconclusive. In a birth cohort (2008–2010, upstate New York), we quantified concentrations of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and bis...

Objective: To explore 76 prenatal maternal plasma EDC concentrations in a healthy obstetric cohort and 7 neonatal anthropometric endpoints by maternal race/ethnicity.

Many factors affect the variation in the exposome and we examined the influence of shared household and partner’s sex in relation to the variation in 128 endocrine disrupting chemical (EDC) exposures among couples. In a cohort comprising 501 couples trying for pregnancy, we measured 128 (13 chemical classes) persistent and non-persistent EDCs and e...

Background: Some non-persistent endocrine disruptors (EDCs) are adversely associated with semen quality and few studies have measured those EDCs in seminal plasma. Objective: To find an association between EDCs in seminal plasma and semen quality parameters. Methods: Five chemical classes of non-persistent EDCs were quantified in seminal plasm...

Context Marine long-chain omega-3 fatty acids have been positively related to markers of fecundity in both men and women. However, seafood, their primary food source, can also be a source of toxicants, which may counteract the reproductive benefits. Objective To examine the relationship of male and female seafood intake with time to pregnancy (TTP...

Aberrant fetal growth is associated with morbidities and mortality during childhood and adult life. Although genetic and environmental factors are known to influence in utero growth, their relative contributions over pregnancy is unknown. We estimated, across gestation, the genetic heritability, contribution of shared environment, and genetic corre...

Background: Accurately identifying pregnancies with accelerated or diminished fetal growth is challenging and generally based on cross-sectional percentile estimates of fetal weight. Longitudinal growth velocity might improve identification of abnormally grown fetuses. Objectives: To complement fetal size standards with fetal growth velocity, de...

Background: Little is known about the predictors of sexual intercourse frequency (SIF) among couples trying to conceive despite the well-established link between SIF and fecundity. Aim: To evaluate men's and women's demographic, occupational, and lifestyle predictors of SIF among couples. Methods: 469 Couples without a history of infertility p...

Study question: Are biomarkers of preconception stress associated with pregnancy loss? Summary answer: Preconception stress, as measured by basal salivary cortisol and alpha-amylase concentrations, is not associated with pregnancy loss. What is known already: Many studies, most of which have been retrospective, have identified an association b...

Background: Ambient air pollution is associated with systemic increases in oxidative stress, to which sperm are particularly sensitive. Although decrements in semen quality represent a key mechanism for impaired fecundability, prior research has not established a clear association between air pollution and semen quality. To address this, we evalua...

Growing evidence supports the importance of men's exposure to non-persistent endocrine disruptors (EDCs) and couple fecundability, as measured by time-to-pregnancy (TTP). This evolving literature contrasts with the largely equivocal findings reported for women's exposures and fecundity. While most evidence relies upon urinary concentrations, quanti...

Objective: To assess parental health status inclusive of infertility and infant outcomes. Design: Birth cohort with cross-sectional analysis of parental health status and infant outcomes. Setting: Not applicable. Patient(s): Parents (n = 4,886) and infants (n = 5,845) participating in the Upstate KIDS birth cohort. Intervention(s): None....

Study question: Is iodine deficiency associated with decreased fecundability? Summary answer: Moderate to severe iodine deficiency is associated with a 46% decrease in fecundability. What is known already: Iodine deficiency is common in women of childbearing age but its effect on fecundability has not been investigated. Study design, size, du...

Three recently completed longitudinal cohort studies have developed intrauterine fetal growth charts, one in the United States and two international. This expert review compares and contrasts the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies, INTERGROWTH-21st and World Health Organization Multi...

Objective This article aims to determine if the number of maternal ultrasound scans where the highest thermal (TI) or mechanical (MI) indices recorded during obstetrical ultrasound exceed 1.0 were associated with neonatal anthropometric measurements. Study Design A prospective cohort of 2,334 nonobese low-risk pregnant women from 12 U.S. clinical s...

Importance Despite the increasing prevalence of pregravid obesity, systematic evaluation of the association of maternal obesity with fetal growth trajectories is lacking. Objective To characterize differences in fetal growth trajectories between obese and nonobese pregnant women, and to identify the timing of any observed differences. Design, Set...

Study question: Does ambient air pollution affect fecundability? Summary answer: While cycle-average air pollution exposure was not associated with fecundability, we observed some associations for acute exposure around ovulation and implantation with fecundability. What is known already: Ambient air pollution exposure has been associated with...

Objective: Equivocal findings have been reported on the association between maternal depression and children's growth, possibly because of the limited attention to its disproportionate impact by child sex. The relationship between the timing of maternal depression and children's growth was assessed in a population-based prospective birth cohort, w...

Objective: To estimate the association of pregnancy loss with common air pollutant exposure. Ambient air pollution exposure has been linked to adverse pregnancy outcomes, but few studies have investigated its relationship with pregnancy loss. Design: Prospective cohort study. Setting: Not applicable. Patient(s): A total of 343 singleton preg...