A peer-reviewed open access journal published by the National Institute of Environmental Health Sciences

Triclosan (TCS) is an antibacterial chemical widely used in personal-care products and an endocrine disruptor. While TCS exposure is associated with insulin resistance and metabolic disorders in animals, few studies have assessed its effect on the risk of gestational diabetes mellitus (GDM) in humans. This study aimed to explore whether maternal urinary TCS level is associated with the risk of GDM and infant birthweight. We examined 620 pregnant women from Shanghai, China in 2012-2013. Urinary TCS level was measured with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and categorized into high, medium and low in tertiles. GDM was defined based on recommendation of International Association of Diabetes and Pregnancy Study Groups (IADPSG). The GDM rate was 12.7%. TCS was detectable (≥0.1 ng/mL) in 97.9% women (median 2.7 ng/mL). There was a positive, but statistically non-significant association between urinary TCS levels and GDM (adjusted odds ratio 1.17; 95%CI: 0.99, 1.39, with each unit increase of log (TCS) ng/mL) with adjustment for urinary creatinine, maternal age, education, passive smoking, parity and prepregnancy BMI categories. 48.1% of infants were females. Birthweight was 122.8 g higher (95% CI: 13.9, 231.6 g) for female infants of women in high TCS (median 13.3 ng/mL) versus low TCS (median 0.77 ng/mL), with adjustment for urinary creatinine, prepregnancy BMI, GDM and other confounders. No association was found between maternal TCS and birthweight in male infants. These results suggested the potential for TCS to be associated with increased risk of GDM and a gender-specific association with higher birthweight among female infants in a population with widespread but moderate exposure to TCS.

Flame retardants are widely used in consumer products to reduce their flammability. Previously used flame retardants have been sequentially banned due to their environmental and human toxicity. Currently, tris(1,3-dichloropropyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP) are among the most commonly used flame retardants. TDCIPP and TPHP are reproductive toxins and have carcinogenic, neurotoxic, and endocrine-disrupting properties. Although high levels of TDCIPP and TPHP have been found in drinking water, seawater, and office air in China, data regarding human exposure are lacking. In this study, we assessed the level of urinary TPHP and TDCIPP metabolites (DPHP and BDCIPP, resp.) in a cohort of pregnant women (N=23) from Shanghai, China, using liquid chromatography-tandem mass spectrometry. DPHP were detected in 100% urine samples, while only four urine samples had detectable level of BDCIPP in this cohort (17% detected). Geometric means of DPHP and BDCIPP concentrations were 1.1 ng/mL (interquartile range [IQR]: 0.6, 1.5 ng/mL) and 1.2 ng/mL (IQR: 0.6, 2.2 ng/mL), respectively. In this small cohort, urinary DPHP and BDCIPP levels were not significantly correlated with miscarriages, neonatal birthweight, gestational diabetes, or maternal age. These data suggest that exposure to TPHP is widespread, and they demonstrate the feasibility of using urinary biomarkers to measure exposures to modern flame-retardant chemicals.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been reported to suppress immune function. However, previous studies on prenatal exposure to PFASs and allergic disorders in offspring provided inconsistent results. We aimed to examine the association between prenatal exposure to PFASs and childhood atopic dermatitis (AD) in offspring up to 24 months of age. A prospective birth cohort study involving 1056 pregnant women was conducted in two hospitals in Shanghai from 2012 to 2015. Prenatal information was collected by an interview with the women and from medical records. Fetal umbilical cord blood was collected at birth. Cord blood plasma PFASs were measured. Children were followed at 6, 12 and 24 months and information on the development of AD was recorded. AD was diagnosed by 2 dermatologists independently based on the questionnaires. Multiple logistic regression was used to compute odds ratio (OR) and corresponding 95% confidence interval (CI) for the association between AD and each PFASs, adjusting for potential confounders. A total of 687 children completed a 2-year follow-up visit and had PFASs measurement. AD was diagnosed in 173 (25.2%) children during the first 24 months. In female children, a log-unit increase in perfluorooctanoic acid (PFOA) was associated with a 2.1-fold increase in AD risk (AOR 2.07, 95% CI 1.13–3.80) after adjusting for potential confounders. The corresponding risk was 2.22 (1.07–4.58) for perfluorononanoic acid (PFNA). The highest PFOA quartile was significantly associated with AD (2.52, 1.12–5.68) compared with the lowest quartile. The highest quartile of PFNA, perfluorodecanoic acid (PFDA) and perfluorohexane sulfonic acid (PFHxS) were associated with AD with AOR (95% CI) being 2.14 (0.97–4.74), 2.14 (1.00–4.57), and 2.30 (1.03–5.15), respectively. Additionally, the second quartile of perfluorododecanoic acid (PFDoA) was associated with a 3.2-fold increase in AD risk (3.24, 1.44–7.27). However, no significant associations were found in male children. Prenatal exposure to PFOA, PFDA, PFDoA and PFHxS significantly increased the risk of childhood AD in female children during the first 24 months of life. In addition, the associations between AD with prenatal exposure to PFNA were close to statistical significance.

Background: Bisphenol A (BPA) has been associated with variable metabolic effects in animal models. It is unknown whether BPA exposure affects glucose tolerance in pregnancy. We aimed to investigate whether maternal urinary BPA concentration is associated with gestational diabetes mellitus (GDM). Methods: This study included 620 pregnant women from Shanghai, China 2012–2013. Maternal urinary BPA concentration was measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). GDM (n = 79) was diagnosed according to the criteria of the International Association of Diabetes and Pregnancy Study Groups (IADPSG). Multivariate regressions were used to explore the relationships of urinary BPA with GDM, plasma glucose levels in the 75-g 2-hour oral glucose tolerance test (OGTT), birth weight, and ponder index. Results: The geometric mean of BPA was 1.32 μg/L. After adjustment for maternal age, education, husband smoking status, prepregnancy body mass index (BMI), and urinary creatinine concentration, plasma glucose at 2 hours in the 75-g OGTT was 0.36 mmol/L lower (95% confidence index [CI] = −0.73, 0.01) for women with urine BPA in the high versus the low tertile. For each unit increase in natural log-transformed BPA, the odds of GDM was reduced by 27% (odds ratio (OR) = 0.73; 95% CI = 0.56, 0.97), the birth weight decreased by 25.70 g (95% CI = −54.48, 3.07), and ponder index was decreased by 0.02 (100 g/cm³) (95% CI = −0.03, 0.00). Conclusions: Higher maternal urinary BPA concentrations were associated with reduced risk of GDM and marginally lower birth weight and ponder index.

Objective: High prepregnancy body mass index (BMI), excessive gestational weight gain (GWG), and gestational diabetes mellitus (GDM) are associated with the risk of childhood obesity. This study aims to examine the extent to which these effects may be mediated through the placenta.Methods: Data included 33,893 mothers and their singleton infants from birth to 7 years old (total 154,590 visits) in the Collaborative Perinatal Project, a U.S. multicenter prospective cohort study from 1959 to 1976. The placentas were weighed after removing cord and membranes. We performed sequential generalized estimating equation‐linear models excluding and including placental weight to evaluate its mediation effect.Results: In this population, 21.7% of mothers had overweight or obesity, 17.3% had excessive GWG, and 350 (1%) had diagnosed GDM; in addition, 7.2% children had obesity. After adjustment for prepregnancy BMI and other covariates, childhood BMI was 0.23 (95% CI: 0.05, 0.40) kg/m² higher for children born to mothers with GDM versus those without GDM. Inclusion of placental weight in the model attenuated the association by 52% to 0.11 (95% CI: −0.06, 0.28) and similarly attenuated the associations with childhood BMI for GWG by 25% and maternal prepregnancy BMI by 17%.Conclusions: Placental weight partly mediates the effects of prepregnancy BMI, excessive GWG, and GDM on childhood BMI.