Use of hair, cosmetic products linked to increased phthalate exposure in pregnancy

Use of hair, cosmetic products linked to increased phthalate exposure in pregnancy | Image Credit: © JackF - stock.adobe.com.

Frequent use of hair products and cosmetics during pregnancy may increase exposure to phthalates—endocrine-disrupting chemicals linked to adverse birth outcomes—according to findings presented at the 2025 American College of Obstetricians and Gynecologists (ACOG) Annual Clinical and Scientific Meeting.^1,2

The study analyzed data from 153 participants in the Atlanta African American Maternal–Child Cohort, focusing on a population that faces higher rates of adverse pregnancy outcomes, including preterm birth. Researchers assessed the relationship between personal care product (PCP) use and urinary phthalate levels early in pregnancy.

Phthalates, commonly found in PCPs such as cosmetics, hair relaxers, and moisturizers, are a known concern for reproductive health. While previous studies have explored phthalates in the general population, few have focused on whether PCP use contributes to phthalate levels of emerging concern, particularly during pregnancy.

Urine samples collected from participants between 8 and 14 weeks of gestation were tested for 12 individual phthalate metabolites. In addition, participants completed questionnaires about the frequency of their personal care product use. Researchers then applied linear regression models to evaluate associations between PCP use and urinary concentrations of several phthalate groups, including the sum of di(2-ethylhexyl) phthalate metabolites (SDEHP), di(isononyl) phthalate metabolites (SDINP), antiandrogenic phthalate metabolites (SAA), and specific individual metabolites such as monocarboxyisononyl phthalate (MCINP).

Results showed that individuals who reported more frequent PCP use had significantly higher urinary phthalate levels. Monthly hair product use was associated with a statistically significant increase in antiandrogenic phthalates (SAA), with a beta coefficient of 0.8 (95% CI, 0.02 to 1.57). Meanwhile, participants who reported weekly or daily use of hair relaxers had significantly lower concentrations of SDEHP (β = –0.16; 95% CI, –0.48 to –0.03), compared with those who did not use relaxers.

Cosmetic use was particularly associated with elevated levels of several phthalates. Users had significantly higher concentrations of SDEHP, SAA, and MCINP compared to non-users.

These findings underscore a potential modifiable exposure risk during early pregnancy. “Among African American pregnant persons, more frequent use of hair products and cosmetics was associated with a significant increase in urinary concentration of phthalates,” the authors concluded.

Given the associations between phthalate exposure and adverse birth outcomes—including preterm birth—researchers emphasized the importance of patient counseling on safer product choices. Reducing the use of phthalate-containing personal care products could serve as a practical strategy to limit exposure during pregnancy.

The study adds to a growing body of evidence suggesting that product formulation and personal care routines can influence maternal health and prenatal environmental exposures.

References:

1. Eatman J, Dunlop A, Barr D, Hill CC, Brennan P, Eick S. Personal Care Product Use Is Associated With Elevated Phthalate Levels During Pregnancy in the Atlanta African American Maternal Child Cohort. Abstract. Presented at: 2025 American College of Obstetricians and Gynecologists (ACOG) Annual Clinical and Scientific Meeting. May 16-18, 2025. Minneapolis, Minnesota.
2. Eatman J, Dunlop A, Barr D, Hill CC, Brennan P, Eick S. Personal Care Product Use Is Associated With Elevated Phthalate Levels During Pregnancy in the Atlanta African American Maternal Child Cohort [ID 1393]. Obstetrics & Gynecology 145(6S):p 78S-79S, June 2025. doi:10.1097/AOG.0000000000005918.074