Summary
An analysis of Bangladesh’s 2025 Multiple Indicator Cluster Survey found blood lead at or above 3.5 µg/dL in 17.7% of tested pregnant women, with levels concentrated in greater Dhaka. The medRxiv preprint also found an association between maternal and young-child lead levels.
A medRxiv preprint analysing Bangladesh’s 2025 Multiple Indicator Cluster Survey estimates that 17.7% of pregnant women with valid blood results had lead levels of at least 3.5 micrograms per decilitre (µg/dL). The results also show a strong geographic concentration: greater Dhaka accounted for a large share of women with higher readings.
The analysis included 1,932 of 2,711 eligible pregnant women, or 71%, who had valid venous blood measurements. Lead can cross the placenta and harm the developing brain, and the authors note that no safe level is known. They used 3.5 µg/dL as an analytical cut-off; it should not be interpreted as a boundary below which exposure is safe.
Higher readings were concentrated around Dhaka
The survey-weighted geometric mean blood lead level was 2.05 µg/dL (95% confidence interval 1.99 to 2.12). Overall, 7.6% of tested women had levels of at least 5 µg/dL.
Greater Dhaka, a grouping the researchers formed after examining district estimates, contained about 12% of pregnant women but 64% (95% CI 54 to 73) of women whose blood lead was at least 5 µg/dL. The concentration makes the region a priority for investigating exposure sources, although the survey analysis does not identify what is driving the higher readings.
The researchers also examined wealth. Women in the richest quintile had a higher prevalence of lead at or above 3.5 µg/dL in the unadjusted analysis (prevalence ratio 3.06, 95% CI 2.02 to 4.63). After adjustment for place, the estimate fell to 1.09 (95% CI 0.72 to 1.67). This suggests that the initial wealth difference was closely tied to where women lived in the survey data. The analysis found no clear association with cosmetics, indoor smoking or nearby battery sites.
Maternal and child lead levels were associated
In a subset of 540 households with a tested child aged 12 to 59 months, maternal blood lead of at least 3.5 µg/dL was associated with a higher prevalence of child lead at or above 5 µg/dL. The adjusted prevalence ratio was 1.50 (95% CI 1.16 to 1.96).
The maternal cut-off identified only 23% of children whose lead levels were at least 5 µg/dL (95% CI 16 to 30). It therefore captured only a minority of those children in this analysis. The association points to households as a relevant setting for further lead assessment, while the survey results do not establish a shared exposure source or show that maternal lead caused the child’s level.
The findings provide national estimates from survey data and identify a marked geographic pattern for follow-up. They are reported as a preprint, and valid blood results were available for 71% of eligible pregnant women.