Abstract
BackgroundPrenatal inorganic arsenic (iAs) exposure is associated with pregnancy outcomes. Maternal capabilities of arsenic biotransformation and elimination may influence the susceptibility of arsenic toxicity. Therefore, we examined the determinants of arsenic metabolism of pregnant women in Bangladesh who are exposed to high levels of arsenic.MethodsIn a prospective birth cohort, we followed 1613 pregnant women in Bangladesh and collected urine samples at two prenatal visits: one at 4–16 weeks, and the second at 21–37 weeks of pregnancy. We measured major arsenic species in urine, including iAs (iAs%) and methylated forms. The proportions of each species over the sum of all arsenic species were used as biomarkers of arsenic methylation efficiency. We examined the difference in arsenic methylation using a paired t-test between first and second visits. Using linear regression, we examined determinants of arsenic metabolism, including age, BMI at enrollment, education, financial provider income, arsenic exposure level, and dietary folate and protein intake, adjusted for daily energy intake.ResultsComparing visit 2 to visit 1, iAs% decreased 1.1% (p < 0.01), and creatinine-adjusted urinary arsenic level (U-As) increased 21% (95% CI: 15, 26%; p < 0.01). Drinking water arsenic concentration was positively associated with iAs% at both visits. When restricted to participants with higher adjusted urinary arsenic levels (adjusted U-As > 50 μg/g-creatinine) gestational age at measurement was strongly associated with DMA% (β = 0.38, p < 0.01) only at visit 1. Additionally, DMA% was negatively associated with daily protein intake (β = − 0.02, p < 0.01) at visit 1, adjusting for total energy intake and other covariates.ConclusionsOur findings indicate that arsenic metabolism and adjusted U-As level increase during pregnancy. We have identified determinants of arsenic methylation efficiency at visit 1.
Highlights
Inorganic arsenic is a ubiquitous, naturally occurring environmental toxicant [1, 2]
Our findings indicate that arsenic metabolism and adjusted urinary arsenic level (U-As) level increase during pregnancy
When restricted to participants with adjusted U-As of > 50 μg/g-creatinine, gestational age at measurement was strongly associated with dimethyl forms of arsenic (DMA)% (β = 0.38, p < 0.01)
Summary
Inorganic arsenic (iAs) is a ubiquitous, naturally occurring environmental toxicant [1, 2]. Pregnant women and developing fetuses are especially susceptible to arsenic exposure. Prenatal arsenic exposure is linked to reduced gestation time, low birth weight, spontaneous abortion, stillbirth, neonatal mortality, and infant mortality [9,10,11,12,13,14,15,16,17]. Identifying factors that influence susceptibility to arsenic toxicity in mothers and children can provide knowledge for risk assessment and guide effective interventions in underserved arsenic-endemic areas. Prenatal inorganic arsenic (iAs) exposure is associated with pregnancy outcomes. We examined the determinants of arsenic metabolism of pregnant women in Bangladesh who are exposed to high levels of arsenic
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call