In utero and peripubertal exposure to phthalates and BPA in relation to female sexual maturation.
Level 3 - non-randomized controlled study
Prospective birth cohort study evaluating prenatal and peripubertal exposures in relation to adolescent outcomes.
PubMed 25173057 · doi:10.1016/j.envres.2014.08.010
What was done
In a Mexico City prospective birth cohort, investigators evaluated urinary concentrations of phthalate metabolites and bisphenol-A (BPA) from pregnant mothers in their third trimester (n=116) and their daughters at ages 8-13 years (n=129). In the girls, concurrent serum hormone concentrations, Tanner staging for breast and pubic hair development, and menarche status were assessed. Multivariable linear and logistic regression models evaluated associations between in utero and peripubertal biomarker levels and female sexual maturation outcomes.
What was found
An interquartile range (IQR) increase in maternal in utero urinary mono-2-ethylhexyl phthalate (MEHP) was associated with 29% higher serum dehydroepiandrosterone sulfate (DHEA-S) in daughters (95% CI: 9.2% to 52.6%) and higher odds of Tanner stage >1 for pubic hair development (OR 5.3, 95% CI: 1.13 to 24.9). Other in utero DEHP metabolites showed similar associations, whereas peripubertal DEHP did not. IQR increases in in utero monobenzyl phthalate (MBzP) and monoethyl phthalate (MEP) were associated with 29% (95% CI: 4.3% to 59.3%) and 25% (95% CI: 2.1% to 54.1%) higher serum testosterone, respectively. Peripubertal MnBP was associated with higher odds of Tanner stage >1 for breast and pubic hair, and MEP showed suggestive associations with menarche. BPA was not associated with hormone concentrations or sexual maturation.
Why it matters
This study suggests that in utero exposure to specific phthalates, rather than peripubertal exposure or BPA, may influence adrenal and gonadal hormone levels and advance the timing of female pubertal development.
Limits
The sample size was small (116 mothers, 129 daughters), leading to very wide confidence intervals for odds ratio estimates. Exposure assessment relied on spot urine samples which may misclassify short-lived endocrine-disrupting chemicals. The study was conducted in a single urban birth cohort, which may limit generalizability.
Cited by
- contradicts A 2016 study found that girls with higher prenatal BPA exposure experienced earlier breast development and menarche.