Maternal exposure to indoor PM2.5 and associated adverse birth outcomes in low socio-economic households, Durban, South Africa

Abstract

PDS 74: Pregnancy outcomes, Exhibition Hall (PDS), Ground floor, August 26, 2019, 1:30 PM - 3:00 PM Background: PM2.5 exposure is associated with adverse pregnancy outcomes such as reduction in birth weight and gestational age. However, this association has not been adequately described with regard to the indoor environments of urban households in low socio-economic countries. Aim: To identify the association between maternal exposure to indoor PM2.5, birth weight and gestational age in mothers participating in the Mother and Child in the Environment birth cohort study in Durban, South Africa. Methods: Pregnant females were recruited from public sector antenatal clinics in Durban, South Africa and followed through to delivery. Households of 770 pregnant females were assessed using a structured walk-through questionnaire to collect information on household materials, occupant activities and outdoor sources. PM2.5 measurements were undertaken in 300 of the 770 households for a period of 24 hours using MiniVol samplers. A predictive model was used to predict PM2.5 levels in unmeasured homes (n=470). The effect of PM2.5 exposure on birth weight and gestational age was assessed by multivariable linear regression models. Results: The mean (SD) for mothers age, gestational age and birth weight was 26 years (5), 39 weeks (2) and 3113 g (546), respectively. For every 1µg/m3 increase in indoor PM2.5, there was 15 g (95% CI: -17.66 to -13.17) reduction in birth weight and 0.01 weeks (95% CI: -0.02 to -0.01) reduction in gestational age, after adjusting for maternal education, smoking status of the mother, sex of infant, marital status and prenatal environmental tobacco smoke. Conclusions: The results add to the evidence that exposure to PM2.5 is associated with adverse pregnancy outcomes such as reduction in birth weight and gestational age. The results suggest that, in order to protect population reproductive health, public health policy should also focus on indoor PM.