Urinary concentration of selected nonpersistent endocrine disrupting chemicals-reproductive outcomes among women from a fertility clinic.

Parabens and benzophenones are compounds widely used in cosmetics and personal care products. Although human exposure is widespread there is a limited number of epidemiological studies assessing the relationship between exposure to these chemicals and female reproductive health. The aim of the study is to explore the relationship between paraben and benzophenone concentrations and reproductive outcomes among women attending a fertility center. This prospective cohort included 450 women undergoing in vitro treatment (IVF) at fertility clinic in Poland. The validated gas chromatography ion-tap mass spectrometry to assess concentrations of parabens in urine (methyl (MP), ethyl (EP), propyl (PP), butyl paraben (BP)) and benzophenone-3 (BP-3) was used. To explore the relationship between concentrations of examined chemicals and reproductive outcomes (methaphase II (MII) oocyte yield, total oocyte yield, implantation rate, fertilization rate, clinical pregnancy, live births), multivariable generalized linear mixed model was used for the analysis. Increased exposure to butyl paraben was associated with a significant decrease in MII oocyte count (p = 0.007) when exposure to BP was treated as the continuous variable. Additionally, the exposure to BP in the highest quartile of exposure also decreases MII oocyte count (p = 0.02) compared to the lowest quartile. Urinary concentrations of BP were not related to total oocyte count, fertilization and implantation rate, clinical pregnancy, and live birth when the exposure variable was continuous variable or in the quartiles of exposure. Exposure to MP, EP, PP, the sum of examined parabens, and benzophenone-3 were not related to any of the examined reproductive outcomes. Exposure to butyl paraben was associated with a decrease in MII oocyte count among women attending fertility clinic rinsing concerns that exposure may have a potential adverse impact on embryological outcomes. The results emphasize the importance to reduce chemicals in the environment in order to minimize exposure. As this is the first study showing such an association, further research is needed to confirm these novel results in other populations.