Organophosphate pesticide exposure during pregnancy associated with total gestational weight gain

Abstract

TPS 742: Adverse birth outcomes 1, Exhibition Hall, Ground floor, August 27, 2019, 3:00 PM - 4:30 PM Background/Aim: Gestational weight gain (GWG) among pregnant women has been increasing globally. Excessive GWG is a potentially modifiable risk factor for medical complications of pregnancy as well as adverse postnatal maternal and child health outcomes. Endocrine disrupting environmental chemicals such as organophosphate (OP) pesticides, which are commonly applied to food crops, are potentially obesogenic. We hypothesized that prenatal exposure to OP pesticides would increase total GWG. Methods: Three dimethyl (DM) and three diethyl (DE) OP metabolites were measured in spot urine samples collected at <18, 18-25, and >25 gestational weeks among participants in the New York University Children’s Health and Environment Study, an ongoing pregnancy cohort. Individual metabolite concentrations were summed to create DM, DE, and total dialkyl phosphate (DAP) metabolite groups. GWG was calculated as the difference between first measured prenatal weight and weight at delivery, extracted from the electronic medical record. We selected potential covariates that were associated with both exposure and outcome, then used backward selection to arrive at the most parsimonious regression models. Results: Among 147 women with exposure and outcome measures, early pregnancy DAP metabolite concentrations were generally correlated (significant Spearman coefficients ranged from 0.23 to 0.69); concentrations of individual metabolites across pregnancy were not. Total DE metabolite concentration, both measured in early pregnancy and averaged across pregnancy, was associated with increased GWG, as was mean total dialkyl phosphate concentration across pregnancy, although the magnitude of the associations was not clinically significant (each 0.02 kg per 10-fold increase in exposure). Conclusions: We found a slight but statistically significant association between prenatal OP pesticide exposure and GWG in this preliminary analysis, which was conducted in a limited sample of participants with available measures. Future analyses will utilize samples from a larger group of participants and explore both trimester-specific exposure and trajectories of exposure across pregnancy.