Background: Millions of people worldwide are drinking water with elevated arsenic concentrations. Epidemiologic studies, mainly cross-sectional in design, have suggested that arsenic in drinking water may affect pregnancy outcome and infant health. We assessed the association of arsenic exposure with adverse pregnancy outcomes and infant mortality in a prospective cohort study of pregnant women.
Methods: A population-based, prospective cohort study of 2924 pregnant women was carried out during 2002–2004 in Matlab, Bangladesh. Spontaneous abortion was evaluated in relation to urinary arsenic concentrations at gestational week 8. Stillbirth and infant mortality were evaluated in relation to the average of urinary arsenic concentrations measured at gestational weeks 8 and 30.
Results: The odds ratio of spontaneous abortion was 1.4 (95% confidence interval [CI] = 0.96–2.2) among women with urine arsenic concentrations in the fifth quintile (249–1253 μg/L; median = 382 μg/L), compared with women in the first quintile (<33 μg/L). There was no clear evidence of increased rates of stillbirth. The rate of infant mortality increased with increasing arsenic exposure: the hazard ratio was 5.0 (95% CI = 1.4–18) in the fifth quintile of maternal urinary arsenic concentrations (268–2019 μg/L; median = 390 μg/L), compared with the first quintile (<38 μg/L).
Conclusions: We found evidence of increased risk of infant mortality with increasing arsenic exposure during pregnancy, with less evidence of associations with spontaneous abortion or stillbirth risk.
From the aInternational Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh; bInternational Maternal and Child Health, Department of Women's and Children's Health, University Hospital, Uppsala University, Uppsala, Sweden; cInstitute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; and dSchool of Public Health, University of California, Berkeley, CA.
Submitted 16 February 2009; accepted 21 June 2010.
Supported by United Nations Children's Fund (UNICEF), Swedish International Development Cooperation Agency (SIDA), UK Medical Research Council, Swedish Research Council, Department for International Development (DfID), International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), Global Health Research Fund-Japan, Child Health and Nutrition Research Initiative (CHNRI), Uppsala University and United States Agency for International Development (USAID) (for The MINIMat project). This arsenic-related substudy was further supported by Swedish International Development Agency (Sida), World Health Organization, United States Agency for International Development (USAID), Swedish Research Council, and the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning. Matlab HDSS is primarily supported by the Department for International Development (DfID).
Correspondence: Anisur Rahman, International Maternal and Child Health, Department of Women's and Children's Health, Uppsala University Hospital, SE-75185 Uppsala, Sweden. E-mail: email@example.com.