Urinary phthalate metabolite concentrations and personal care product use during pregnancy - Results of a pilot study

Phthalates are reproductive toxicants commonly found in personal care products (PCPs). These endocrine disrupting chemicals are associated with pregnancy complications, including gestational diabetes. Yet, little is known about PCP use as a contributor to urinary phthalate metabolite concentrations in pregnancy.

We conducted a pilot study among 108 pregnant participants to examine the associations of self-reported PCP use with 14 phthalate and 2 DINCH (di(isononyl) cyclohexane-1,2-dicarboxylate) metabolite concentrations measured in single spot urine samples during pregnancy (median: 36 weeks of gestation). At the time of urine collection, participants self-reported use of hair products (within the last month) and other PCPs (within the last 48 h). We used linear regression to estimate associations for natural log-transformed, specific gravity-corrected concentrations of common PCP-associated phthalate metabolites (monoethyl phthalate [MEP], mono-n-butyl phthalate [MBP], and mono-isobutyl phthalate [MIBP]) in our primary analyses, and additional phthalate metabolites in secondary analyses.

Most urinary metabolites were detected for >90% of participants. Participants who reported using hair oil within the past month had MEP concentrations 125% higher (95% confidence interval [CI]: -0.1, 408) than non-users. For other personal care products, we observed the greatest percent difference in PCP-associated metabolites for MIBP among hair gel users (39.3%, 95% CI: -6.3, 107) and for MEP among conditioner/crème rinse users (-55.4%, 95% CI: -76.4, -15.6) compared to non-users.

Findings suggest that self-reported use of hair oils during late pregnancy may be associated with higher urinary concentrations of MEP. Hair gel use in late pregnancy may also be associated with higher urinary phthalate metabolite concentrations, while conditioner/crème rinse use may be associated with lower levels if MEP.