CHRONIC ARSENIC EXPOSURE AND ADVERSE PREGNANCY OUTCOMES IN BANGLADESH

Abstract

Introduction Chronic arsenic exposure through drinking water has the potential to cause adverse pregnancy outcomes, though the association is not conclusive. This cross sectional study was carried out in twothree arsenic affected districts of Bangladesh to determine the association between chronic arsenic exposure through drinking water and spontaneous abortion, stillbirth and neonatal death. Methods In this cross-sectional study, 533 married, non-smoking females of reproductive age (range 15 to 49 years) with a history of at least one pregnancy, who had been living in the study area since their marriage and drank water from the respective tube well prior to and during the pregnancy were interviewed. Information on sociodemographics, drinking water use, occupation and adverse pregnancy outcomes were obtained through a structured pretested interviewer-administered questionnaire. Out of 2138 tube wells, 203198 water samples were measured using UV/Visible spectrophotometry method while 15 were measured by flow-injection hydride generation atomic absorption spectrometry (FIHG-AAS). Results A total of 533 female participated in this study. Their mean age was 31.22 years (standard deviation [SD] = 6.44) and the average duration of arsenic exposure of the participants was 8.11 years (SD = 7.32), median duration of exposure was 7 years. Out of the study subjects, 257 (48%) of the study participants did not receive any formal education. The majority of them (51%) got married before the age of 16-years. The mean number of pregnancies was 3.72 (SD = 1.79) and mean number of live births was 3.48 (SD = 1.65). Melanosis was observed among 51 (10%) and keratosis was observed among 43 (8%) participants. The mean and median arsenic concentration of the tube well drinking water of the study participants was 279(SD = 355) μg/L and 116 ppbμg/L respectively, ranging from non-detectable level to 1710 ppbμg/L. 356 (67%) participants were exposed to arsenic at more than 50 ppbμg/L, the recommended level of arsenic in drinking water for Bangladesh. Overall incidence of spontaneous abortion, stillbirth and neonatal death in this study were found as 59.61/1000 live birth, 35.55 /1000 live birth and 49.31 /1000 live birth respectively. Excess risks for spontaneous abortion, stillbirth and neonatal death were observed among the participants exposed to increasing concentrations of arsenic in drinking water, after adjusting for participant's education, age at marriage, antenatal care and parity. The odds ratio (OR) for spontaneous abortion, stillbirth and neonatal death was 1.93 (95% Confidence Interval [CI]: 1.11, 3.37), 1.82 (95% CI: 0.94, 3.51) and 1.89 (95% CI: 1.02, 3.53) respectively for females drinking water with >50ppbμg/L compared to £50ppbμg/L arsenic concentration. These risks are both clinically and statistically significant except stillbirth. There was, however, a statistically significant dose-response association between increasing arsenic concentration and stillbirth (p = 0.02), neonatal death (p = 0.01).