Pre- and Postnatal Arsenic Exposure and Body Size to 2 Years of Age: A Cohort Study in Rural Bangladesh

BACKGROUND: Exposure to arsenic via drinking water has been associated with adverse pregnancy outcomes and infant morbidity and mortality. Little is known, however, about the effects of arsenic on child growth. OBJECTIVE: We assessed potential effects of early-life arsenic exposure on weight and length of children from birth to 2 years of age. METHODS: We followed 2,372 infants born in a population-based intervention trial in rural Bangladesh. Exposure was assessed by arsenic concentrations in urine (U-As) of mothers (gestational weeks 8 and 30) and children (18 months old). Child anthropometry was measured monthly in the first year and quarterly in the second. Linear regression models were used to examine associations of U-As (by quintiles) with child weight and length, adjusted for age, maternal body mass index, socioeconomic status, and sex (or stratified by sex). RESULTS: Median (10th-90th percentiles) U-As concentrations were about 80 (25-400) mu g/L in the mothers and 34 (12-159) mu g/L in the children. Inverse associations of maternal U-As with child's attained weight and length at 3-24 months were markedly attenuated after adjustment. However, associations of U-As at 18 months with weight and length at 18-24 months were more robust, particularly in girls. Compared with girls in the first quintile of U-As (< 16 mu g/L), those in the fourth quintile (26-46 mu g/L) were almost 300 g lighter and 0.7 cm shorter, and had adjusted odds ratios (95% confidence interval) for underweight and stunting of 1.57 (1.02-2.40) and 1.58 (1.05-2.37), respectively, at 21 months. CONCLUSIONS: Postnatal arsenic exposure was associated with lower body weight and length among girls, but not boys.