Blood lead and other metals among pregnant women in Bangladesh: national prevalence, geographic variation and household child exposure

Background. Lead crosses the placenta and harms the developing brain, and no safe level is known. Bangladesh lacks national estimates of lead exposure in pregnancy. Objectives. We estimated blood lead in pregnant women nationally, described where and in whom it was raised, and examined links with child lead and haemoglobin. Methods. In the Bangladesh Multiple Indicator Cluster Survey 2025, 1,932 of 2,711 eligible pregnant women (71%) had valid venous blood results. Survey-weighted modified Poisson models estimated prevalence ratios (PR) for blood lead of 3.5 microgram/dL or more, an analytical cut-off. We also studied 540 households with a tested child aged 12 to 59 months. Results. Among tested women, geometric mean blood lead was 2.05 microgram/dL (95% CI 1.99 to 2.12). In all, 17.7% (15.7 to 19.9) had 3.5 microgram/dL or more and 7.6% (6.1 to 9.3) had 5 microgram/dL or more. Greater Dhaka, defined after inspecting district estimates, held 12% of pregnant women but 64% (54 to 73) of those at 5 microgram/dL or more. The richest quintile had a crude PR of 3.06 (2.02 to 4.63, P<0.001), attenuated to 1.09 (0.72 to 1.67, P=0.678) after adjustment for place. No clear association was seen with cosmetics, indoor smoking or nearby battery sites. A woman's lead of 3.5 microgram/dL or more was associated with child lead of 5 microgram/dL or more (adjusted PR 1.50, 1.16 to 1.96, P=0.002). This cut-off identified only 23% (16 to 30) of them. Conclusions. Raised blood lead in pregnancy varied sharply by place and was highest in greater Dhaka. The crude wealth association was markedly attenuated after adjustment for place. Maternal lead was linked with child lead, but most exposed children lived with women below the cut-off. These findings support source investigation in greater Dhaka and evaluation of targeted lead assessment for women and children.