Prenatal, peripubertal exposure to personal care products disrupts puberty timing in girls
Prenatal and peripubertal exposure to chemicals found in personal care and consumer products appears to interfere with pubertal timing in girls, according to a recent study.
“Specifically, prenatal urinary concentrations of triclosan and 2,4-dichlorophenol were associated with earlier menarche, and prenatal concentrations of monoethyl phthalate (MEP) were associated with earlier pubarche in girls,” researchers said, noting that such interactions were present in boys but to a lesser degree.
A total of 179 girls were included in the study, in whom the median ages at thelarche, pubarche and menarche were 9.2, 10.3 and 11.7 years, respectively. In comparison, in 159 boys, the median ages at gonadarche and pubarche were 10.8 and 12.2 years, respectively. [Human Reprod 2018;doi:10.1093/humrep/dey337]
Elevated prenatal concentrations of MEP altered the timing of pubertal milestones in girls. Specifically, each doubling of prenatal MEP was associated with a significant shift in female pubarche by –1.3 months (95 percent CI, –2.5 to –0.1; p<0.05).
Similar effects were observed for levels of prenatal triclosan and 2,4-dichlorophenol, such that a twofold increase in each biomarker was associated with a shift in the timing of menarche by –0.7 (–1.2 to –0.2; p<0.01) and –0.8 (–1.6 to –0.0; p<0.05) months, respectively.
Peripubertal exposure also appeared to disrupt the timing of puberty in girls. For instance, each doubling in the urinary concentration of methyl paraben led to earlier thelarche (mean shift, –1.1 months; –2.1 to –0.0; p<0.05), pubarche (mean shift, –1.5 months; –2.5 to –0.4; p<0.01) and menarche (mean shift, –0.9 months; –1.6 to –0.1; p<0.05).
Moreover, a doubling of propyl paraben resulted in a mean pubarche shift of –0.8 months (–1.6 to –0.1; p<0.05), while a doubling of 2,5-dichlorophenol delayed pubarche onset by a mean of 1.0 month (0.1–1.9; p<0.05).
“No prenatal biomarkers were associated with pubertal timing in boys. With peripubertal concentrations, we observed an association of earlier gonadarche with each doubling of propyl paraben,” said researchers, noting that the observed mean shift was –1.0 months (–1.8 to –0.1; p<0.05).
“We found evidence that prenatal and peripubertal exposure to certain phthalates, parabens and phenols present in personal care and consumer products was associated with pubertal timing in girls, but less so in boys,” they summarized.
In the present study, the participating mothers were interviewed twice during pregnancy (mean gestation weeks 14.0 and 26.9) and when their children were 9 years of age. Only those with complete biomarker information and who qualified for low income health insurance were eligible for inclusion.
Solid phase extraction combined with isotope dilution high performance liquid chromatography–electrospray ionization–tandem mass spectrometry was used to quantify the level of urinary metabolites from spot samples collected from the pregnant mothers and children during the time of interview.
“Although personal care product-use habits tend to be fairly consistent, as shown by the moderate correlations between the paraben and phenol concentrations during pregnancy, multiple spot urine samples per time window would have been preferable,” said researchers.
Regardless, the findings of the present study identify chemicals of interest in personal care products and contribute “to a growing literature that suggests that exposure to certain endocrine disrupting chemicals may impact timing of puberty in children,” they added.