Blood lead levels during pregnancy in women living in Rio de Janeiro, Brazil

The present study was designed to determine variations in blood lead levels during pregnancy and the influence of physiological anemia during this period on these findings. An exploratory study was made of a cohort of 38 pregnant women whose blood was tested for lead level and erythrocyte counts at different stages of pregnancy. The values obtained for lead were adjusted to take account of the erythrocyte count values, in order to control the influence of pregnancy-related physiological anemia on blood lead levels. A statistically significant increase in blood lead levels at a 5% level was observed between the first and third trimester. The median blood lead levels for the first, second and third trimester were 5.1 μg/dl, 5.9 μg/dl, and 8.25 μg/dl, respectively (Kruskal–Wallis=11.9, P<0.002). Statistical significance was also shown for raw data, when blood lead levels were not adjusted to erythrocyte count values. The median blood lead levels observed in this latter situation were 5.55 μg/dl, 5.65 μg/dl and 7.3 μg/dl, respectively (Kruskal–Wallis=8.3, P<0.02). It is concluded that there was a significant increase in blood lead concentration during pregnancy in this group of women.