Vaginal douching and racial/ethnic disparities in phthalates exposures among reproductive-aged women

Certain phthalates are commonly used in many fragranced personal care/beauty products, including vaginal douches.  Phthalates may act as potential endocrine disrupters and have been associated with adverse reproductive and development outcomes.  However, no prior study has examined whether feminine hygiene products increase internal exposure to phthalates. This issue may be of particular concern to African American women, who report higher use of vaginal douches than other racial/ethnic groups.  Studies have also found that geographic location may have an impact on occurrence and frequency of douching, and that douching is more common in southern regions of the US. The goal of the study was to examine the relationship between self-reported use of vaginal douches and urinary phthalates exposures among a nationally-representative sample of the US reproductive-aged women.  

We used data on 739 reproductive-aged women from the National Health and Nutrition Examination Survey (2001-2004) to examine the association between self-reported vaginal douche use and urinary levels of two phthalate metabolites: mono-n-butyl phthalate (MnBP) and mono-ethyl phthalate (MEP). Percent change estimates were calculated using beta coefficients from linear regression models after covariate adjustment.  All statistical analyses were adjusted for the non-random sampling design and the sample population weights.

We found that black women were 2-3 times more likely to report douche use in the past month, compared to White and Mexican American women.  Women who reported douche use had 34% (95% confidence interval (CI: (1%, 77%); p < 0.01) higher levels of MEP than non-users.  There was a monotonic dose-response relationship between frequency of douching and MEP levels (ptrend <0.001).  The high use group ( ≥ 2 times/month) had 152% (CI: (71%, 272%); p < 0.01) higher levels of MEP than non-users. The association between race/ethnicity and MEP was partially mediated by douche use.  

We conclude that vaginal douching may be an important source of DEP exposure among US reproductive aged women and that vaginal douche use may contribute to racial/ethnic disparities in phthalates exposure. Future work should examine the health consequences of chemical exposures from feminine hygiene product use, particularly in regions where douching occurrence and frequency may be higher.