Urinary phthalate metabolite concentrations and maternal weight during early pregnancy

Abstract

Background Phthalates are a class of chemicals that may be associated with obesity in non-pregnant populations. Little is known about the association between pregnancy phthalate exposure and maternal obesity. Objective We evaluated the association between early-pregnancy urinary concentrations of specific phthalate metabolites and the distribution of body mass index (BMI, cross-sectional), and early gestational weight gain (GWG, prospective). Methods We measured 1st trimester urinary phthalate metabolite concentrations (median 9.9 weeks gestation) in 347 women from the LIFECODES pregnancy cohort (Boston, MA), who delivered term births. All measures were adjusted for specific-gravity and log-transformed. We used quantile regression to evaluate shifts in the entire outcome distributions, calculating multivariable-adjusted differences in the associations between these phthalate metabolites and BMI and GWG at the 25th, 50th, and 75th percentiles of these anthropometric outcomes. Results Higher concentrations of mono-ethyl phthalate (MEP) were associated with a rightward shift of 2.8 kg/m2 at the 75th percentiles of BMI (lowest vs highest quartile, 95% CI: 0.2–5.4) and 1.3 kg at the 75th percentiles of early GWG (lowest vs second quartiles, 95% CI: 0.3–2.4). A significant right-shift in the upper tail of BMI was also observed at higher concentrations of mono-benzyl (MBzP), mono-3-carboxypropyl (MCPP), and a summary measure of di-(2-ethylhexyl) phthalate metabolites (ΣDEHP). ΣDEHP was also associated with lower GWG. Conclusions Certain phthalates may be associated with shifts in maternal obesity measures, with MEP, MBzP, MCPP, and ΣDEHP being cross-sectionally associated with 1st trimester BMI and MEP and ΣDEHP being positively and inversely associated with early GWG, respectively.

Exposure to Bisphenol A and phthalates metabolites in the third trimester of pregnancy and BMI trajectories

“…Similarly, higher values were reported by Vafeiadi et al among a Greek population during the first trimester of pregnancy (1.2 ng/mL). For phthalates metabolites, higher GM values were reported by Buckley et al among three pooled cohorts from the USA (μg/L; MEP: 154.1; MiBP: 6.45; MCPP: 2.08; MBzP: 11.6; MECPP: 35.7; MEHHP: 21.4; MEHP: 4.92; MEOHP: 18.0) and by Bellavia et al among women in their first trimester of pregnancy in Boston (μg/L; MEP: 137.8; MiBP: 7.3; MBzP: 7.0; MCPP: 2.1). While prenatal exposure to BPA was positively associated with BMI z ‐ score in boys, but negatively in girls, at 4 years of age in the Rhea cohort , we did not find any differences in BMI trajectories by levels of BPA exposure, which may be due to the high proportion of values measured <LOQ.…”

First trimester maternal exposures to endocrine disrupting chemicals and metals and fetal size in the Michigan Mother–Infant Pairs study

“…For example, lower free triiodothyronine (T3) and higher BMI were associated with higher urine MCPP among pregnant women. 41,42 Lower maternal thyroid hormone levels and higher BMI increase the risk for larger offspring. 43,44 In a different subset of MMIP participants recruited in the study's early years, we previously reported significant associations among female newborns between first trimester MCPP and increased birth length, as well as maternal urinary MCPP at delivery and higher birth weight.…”

Bisphenol A and Phthalates in Diet: An Emerging Link with Pregnancy Complications

“…In the Lifecodes cohort study, which enrolled 350 pregnant women, mean levels of maternal urinary MEP throughout pregnancy were positively associated with weight gain. Accordingly, the risk of impaired glucose tolerance (IGT) increased with high levels of this phthalate metabolite at the second trimester [91,92].…”

“…In the Lifecodes cohort study, which enrolled 350 pregnant women, mean levels of maternal urinary MEP throughout pregnancy were positively associated with weight gain. Accordingly, the risk of impaired glucose tolerance (IGT) increased with high levels of this phthalate metabolite at the second trimester [91,92]. More recently, Shaffer et al found that high mean levels (average concentration between first and third trimesters) of maternal urinary MEP significantly increased the odds of IGT and GDM [93].…”