Urinary levels of phthalate metabolites in women associated with risk of premature ovarian failure and reproductive hormones

Phthalates, a class of high production-volume chemicals widely used as plasticizers, have been shown to impair ovarian functions in female animals, but epidemiological evidence is very limited. In this case-control study, the associations between phthalate exposure and premature ovarian failure (POF) in women were assessed. A total of 173 POF cases and 246 control women were recruited in Zhejiang, China. The urinary concentrations of 8 phthalate metabolites and the serum levels of ovary-related hormones were determined. Mono-isobutyl phthalate (MiBP) was the metabolite with the highest median concentration of 27.23 μg/g of creatinine in the whole group. Compared with the lowest quartile, higher urinary concentrations of MiBP were significantly associated with increased odds of POF (OR = 1.38, 95% CI: 0.73-2.61 for the fourth quartile; p for trend = 0.01). The estradiol/FSH ratio, a marker of ovarian function, in control women was significantly negatively associated with the urinary concentrations of most tested phthalate metabolites. Our results suggest that exposure to some phthalates may impair ovarian function and increase the odds of POF in women.