Association Between Blood Lead Levels, Haemoglobin and Anaemia in Pregnant Women: A Register-Based Cohort Study From the Autonomous Republic of Adjara, Georgia

Many children and pregnant women in the Autonomous Republic of Adjara, Georgia experience elevated blood lead levels (BLLs) due to considerable environmental exposure from both known and unknown sources. Anaemia during pregnancy is also common in Georgia; however, the association between lead exposure and anaemia during pregnancy has not yet been assessed. This retrospective cohort study aimed to investigate the association between BLLs and haemoglobin (Hb) levels and anaemia among pregnant women. We included 3594 pregnant women who underwent BLL testing between September 2020 and July 2023. Data on Hb levels were obtained from the Georgian Birth Registry. Pregnant women were included if they had BLL testing before Hb measurements across different trimesters. The prevalence of anaemia among the participants was 23.9%, with 4.6% experiencing moderate-to-severe anaemia. Forty-two percent of pregnant women had BLLs ≥5.0 µg/dl. Each BLL increment was associated with a 0.013 g/dl (95% CI: 0.005-0.022) increase in Hb after adjusting for confounders. However, there was no statistically significant association between BLLs and the odds of moderate-to-severe anaemia (AOR for BLL ≥10 µg/dl: 0.92, 95% CI: 0.51-1.67). The weak positive association between BLL and Hb levels may therefore reflect residual confounding from unmeasured lifestyle factors such as diet and dietary supplement use.