Child marriage, maternal serum metal exposure, and risk of preterm birth in rural Bangladesh: evidence from mediation analysis

BACKGROUND: The prevalence of preterm birth in Bangladesh is estimated to be 19.1%, the highest in the world. Although prenatal exposure to several metals has been linked with preterm birth, fewer prospective studies have investigated the socioeconomic factors that affect metal exposure, leading to preterm birth risk. OBJECTIVE: We aim to identify novel metal biomarkers and their critical exposure windows, as well as the upstream socioeconomic risk factors for preterm birth in rural Bangladeshi, to shed light for future interventional strategies. METHODS: This study included data from 780 mother-offspring pairs, who were recruited to participate in a prospective birth cohort in Bangladesh (2008-2011). Serum concentrations of 19 metals were measured in the first and second trimesters using inductively coupled plasma…