Investigating the Impact of Maternal Residential Mobility on Identifying Critical Windows of Susceptibility to Ambient Air Pollution During Pregnancy

Abstract

Identifying periods of increased vulnerability during pregnancy to air pollution with respect to the development of adverse birth outcomes can improve understanding of possible mechanisms of disease development and provide guidelines for protection of the child. Exposure to air pollution during pregnancy is typically based on the residence at delivery, potentially resulting in exposure misclassification and biasing the estimation of critical windows. In this work, we determine the impact of maternal residential mobility during pregnancy on defining weekly exposure to PM₁₀ and the estimation of windows of susceptibility for term low birth weight utilizing birth cohort datasets from Connecticut (1988–2008) that include information on all residential addresses for each woman between conception and delivery. A simulation study is designed to investigate the impact of increasing levels of mobility on critical window identification. Increased PM₁₀ exposure during pregnancy weeks 16–18 is associated with an increased probability of term low birth weight. Ignoring residential mobility when defining weekly exposure has only minor impact on the identification of critical windows for PM₁₀ and term low birth weight in the data application and simulation study. Critical window identification is robust to exposure misclassification caused by ignoring residential mobility in these Connecticut birth cohorts.