Arsenic Exposure During Pregnancy and Size at Birth: A Prospective Cohort Study in Bangladesh

The authors evaluated the association of prenatal arsenic exposurewith size at birth (birth weight, birth length, head and chestcircumferences). This prospective cohort study, based on 1,578mother-infant pairs, was conducted in Matlab, Bangladesh, in2002–2003. Arsenic exposure was assessed by analysis ofarsenic in urine collected at around gestational weeks 8 and30. The association of arsenic exposure with size at birth wasassessed by linear regression analyses. In analysis over thefull range of exposure (6–978 µg/L), no dose-effectassociation was found with birth size. However, significantnegative dose effects were found with birth weight and headand chest circumferences at a low level of arsenic exposure(<100 µg/L in urine). In this range of exposure, birthweight decreased by 1.68 (standard error (SE), 0.62) g for each1-µg/L increase of arsenic in urine. For head and chestcircumferences, the corresponding reductions were 0.05 (SE,0.03) mm and 0.14 (SE, 0.03) mm per 1 µg/L, respectively.No further negative effects were shown at higher levels of arsenicexposure. The indicated negative effect on birth size at a lowlevel of arsenic exposure warrants further investigation. arsenic; Bangladesh; birth weight; cohort studies; maternal exposure; urine