Arsenic exposure in pregnancy: a population-based study in Matlab, Bangladesh.

This study assessed the exposure of pregnant women to arsenic in Matlab, Bangladesh, an area with highly-elevated concentrations of arsenic in tubewells, by measuring concentrations of arsenic in urine. In a defined administrative area, all new pregnancies were identified by urine test in gestational week 6-8, and women were asked to participate in the assessment of arsenic exposure. Urine for analysis of arsenic was collected immediately and in gestational week 30. In total, 3,426 pregnant women provided urine samples during January 2002-March 2003. There was a considerable variation in urinary concentrations of arsenic (total range 1-1,470 microg/L, adjusted to specific gravity 1.012 g/mL), with an overall median concentration of 80 microg/L (25th and 75th percentiles were 37 and 208 microg/L…