Birth outcomes and organophosphate pesticide exposure in the SAWASDEE birth cohort

Abstract

TPS 741: Adverse birth outcomes 2, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background: The Study of Asian Women and Offspring’s Development and Environmental Exposures (SAWASDEE), a prospective birth cohort, has been initiated in two districts in the Chiang Mai Province in Northern Thailand. The objectives of this study are (1) to better understand exposures during critical developmental windows in pregnancy; (2) to examine the direct effects of prenatal insecticide exposure on neurodevelopment; and (3) to further develop the capacity for independent research in Thailand. We are currently evaluating exposure metrics in relation to birth outcomes. APGAR is an important measure of neonatal health at birth; low APGAR scores have been found to be associated with adverse developmental outcomes. Methods: We investigated the association of maternal first trimester self-reported handling of pesticides during pregnancy and infant APGAR scores at 1 and 5 minutes. To determine variables included in the model as potential confounders we used a Directed Acyclic Graph (DAG). We excluded preterm (<37 weeks) births and women who reported experiencing pregnancy complications. To address the clustering structure of our data we used generalized estimating equation (GEE) to evaluate the relationship between maternal handling of pesticides and infant APGAR score. Results: Of the >300 enrolled pregnant women (median weeks of gestation at enrollment=9±2.6 weeks). The average age of the women is 25.2±2.6 years with 17% reporting they have never attended school. Of the over 200 births thus far (78.3% natural, 21.7% cesarean section), the median gestational age at birth is 38±1.2 weeks, and the average birth weight is 2900±427.1 g. The adjusted relative risk (RR) of a 1-minute APGAR score being below the median value among infants whose mothers reported handling pesticides is 1.57 (95% CI: 0.78, 3.20) (Crude: 1.67 (95% CI: 0.89, 3.30)). Conclusions: It is important that future studies evaluate the impacts of environmental exposures on critical windows of in-utero development.