Association of Prenatal Urinary Concentrations of Phthalates and Bisphenol A and Pubertal Timing in Boys and Girls.
Level 3 - non-randomized controlled study
Prospective longitudinal birth cohort study evaluating prenatal exposures against adolescent developmental outcomes.
PubMed 30203993 · doi:10.1289/EHP3424
What was done
Researchers measured urinary concentrations of eight phthalate metabolites and bisphenol A (BPA) at two time points during pregnancy among mothers in the CHAMACOS longitudinal birth cohort. Clinical Tanner staging was evaluated in their children every 9 months from ages 9 to 13 years (assessing thelarche, pubarche, and menarche in girls; gonadarche and pubarche in boys). Accelerated failure time models were used to evaluate associations between prenatal chemical exposures and pubertal timing, including stratification by child overweight/obese status.
What was found
The abstract reports directional associations without numerical effect estimates or confidence intervals. The sum of di(2-ethylhexyl) phthalate (DEHP) metabolites, monobenzyl phthalate (MBzP), and BPA were associated with later onset of at least one pubertal milestone in girls and earlier onset of at least one milestone in boys. Specifically in girls, MBzP and DEHP metabolites were linked to later thelarche across all girls, and DEHP to later menarche; monocarboxynonyl phthalate, monocarboxyoctyl phthalate, mono(3-carboxypropyl) phthalate, and BPA were associated with later pubarche and menarche primarily in normal-weight girls. In boys, BPA and all measured phthalate biomarkers were associated with earlier gonadarche and pubarche overall and among overweight/obese boys, while phthalate associations were near null or positive among normal-weight boys.
Why it matters
This study provides prospective evidence that common endocrine-disrupting chemicals measured during gestation are linked to sex-divergent alterations in pubertal timing, with associations differing by childhood adiposity.
Limits
The abstract omits the sample size (replaced by formula placeholders in the text) and does not provide numerical effect estimates or confidence intervals. As an observational cohort study, findings may be subject to residual confounding, exposure misclassification from spot urine measurements, and multiple testing across chemical biomarkers and clinical endpoints.
Cited by
- contradicts A 2016 study found that girls with higher prenatal BPA exposure experienced earlier breast development and menarche.