Effects of Maternal Homelessness, Supplemental Nutrition Programs, and Prenatal PM2.5 on Birthweight.

Jongeun Rhee,Kevin James Lane,Jaime E Hart,M Patricia Fabian,Megan Sandel,Sharon Coleman,Maayan Yitshak Sade,Francine Laden,Jonathan I Levy,Antonella Zanobetti,Stephanie Ettinger De Cuba,Itai Kloog,Joel Schwartz

doi:10.3390/ijerph16214154

Abstract

Few studies examined the impact of maternal socioeconomic status and of its combined effects with environmental exposures on birthweight. Our goal was to examine the impact of maternal homelessness (mothers ever homeless or who lived in shelters during pregnancy) and participation in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) during pregnancy in conjunction with air pollution exposure on birthweight in the Boston-based Children’s HealthWatch cohort from 2007 through 2015 (n = 3366). Birthweight was obtained from electronic health records. Information on maternal homelessness and WIC participation during pregnancy were provided via a questionnaire. Prenatal fine particulate matter (PM2.5) exposures, estimated at the subject’s residential address, were calculated for each trimester. We fit linear regression models adjusting for maternal and child characteristics, seasonality, and block-group-level median household income and examined the interactions between PM2.5 and each covariate. Prenatal maternal homelessness was associated with reduced birthweight (−55.7 g, 95% CI: −97.8 g, −13.7 g), while participating in WIC was marginally associated with increased birthweight (36.1 g, 95% CI: −7.3 g, 79.4 g). Only average PM2.5 during the second trimester was marginally associated with reduced birthweight (−8.5 g, 95% CI: −19.3, 2.3) for a 1 µg/m3 increase in PM2.5. The association of PM2.5 during the second trimester with reduced birthweight was stronger among non-Hispanic Black mothers and trended toward significance among immigrants and single mothers. Our study emphasizes the independent and synergistic effects of social and environmental stressors on birthweight, particularly the potentially protective effect of participating in WIC for vulnerable populations.

Highlights

IntroductionMaternal and environmental factors such as socioeconomic status, psychosocial stress, housing instability, and ambient air pollution have been independently associated with low birthweight [4,5,6,7,8,9,10,11,12,13,14,15]
Low birthweight is a leading cause of neonatal morbidity and mortality [1,2,3]
40% of mothers were immigrants, and 84% participated in WIC during pregnancy

Summary

Introduction

Maternal and environmental factors such as socioeconomic status, psychosocial stress, housing instability, and ambient air pollution have been independently associated with low birthweight [4,5,6,7,8,9,10,11,12,13,14,15]. Few studies examined the impact of social stressors, e.g., individual and areal poverty, and their combined effects with environmental exposures on birthweight [16,17]. Investigating combined effects is important to identify the most vulnerable populations and optimize interventions to improve neonatal and child health. Housing instability is a social condition that may act as a severe stressor during pregnancy and affect infants’ birthweight [18]. Homeless women are more likely to be undernourished, experience abusive situations, have poor mental health, and be exposed to substance use during pregnancy [13,19,20]

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