Organophosphate Pesticide Exposures and Menstrual Cycle Characteristics in Chinese Preconception Women

Organophosphates (OPs) are the most heavily used pesticides in China. The Chinese population, including preconception women, is highly exposed. Yet, little is known regarding the associations of OPs on menstruation in humans. We conducted a cross-sectional analysis in women preparing for pregnancy to investigate the relationship between biomarkers of OP exposure and menstrual cycle characteristics. From 2013 to 2015, 627 women attended free preconception care clinics at two maternity hospitals in Shanghai were included. Information on menstrual cycle characteristics was obtained through questionnaires. OP exposure was assessed by measuring urine concentrations of six dialkylphosphate metabolites (dimethylphosphate, dimethylthiophosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate, and diethyldithiophosphate). The relationship between concentrations of dialkylphosphate metabolites and menstrual cycle characteristics was analyzed using multiple linear regression models and logistic regression models. Log-transformed DEs (the sum of diethylphosphate and diethylthiophosphate) were related to a higher risk of irregularity of menstrual cycles [adjusted odds ratio (OR) = 2.36, 95% confidence interval (CI):1.28, 4.34]. Subjects with higher concentration of DEs (log-transformed) had shorter bleeding duration (adjusted beta= -0.33, 95% CI: -0.64, -0.02).The findings suggest that OP exposure may be associated with alterations in menstrual function in preconception women.