Time-trends of blood lead levels from 2020 to 2023 in pregnant and breastfeeding women from Adjara, Georgia—A birth registry-based study

Abstract

Background

In response to substantial lead exposure, the autonomous republic of Adjara in Georgia initiated complementary blood lead level (BLL) testing for pregnant women as part of their antenatal care services in 2020.

Objectives

To study the background BLLs in pregnant and breastfeeding women in Adjara and explore the time-trends of BLLs from September 2020 to July 2023.

Methods

We used data on BLLs during pregnancy or postpartum from the lead screening program in Adjara, combined with data from the Georgian Birth Registry, totaling 9,510 women. To study the temporal changes in BLLs, we used independent samples t-tests and chi-square tests.

Results

In 2020, the mean (standard deviation [SD]) BLL was 8.8 (5.4) μg/dL, declining annually by 1.0–2.2 μg/dL to reach 3.6 (2.5) μg/dL in 2023. The prevalence of pregnant women with BLLs ≥3.5, ≥5.0, and ≥10.0 μg/dL also decreased from 2020 to 2023. Specifically, 21.2% of women in their first trimester had BLLs ≥10 μg/dL in 2020, compared with 2.3% in 2023. Similarly, 73.5% had BLLs ≥5.0 μg/dL in 2020, which declined to 20.4% in 2023. Lastly, 89.1% had BLLs ≥3.5 μg/dL in 2020, decreasing to 38.6% in 2023.

Discussion

In 2023, nearly 40% of women in their first trimester had BLLs of ≥3.5 μg/dL, a level considered the reference value in the United States (US) and corresponding to the 97.5th percentile among US children. From 2020 to 2023, the mean BLL in pregnant women decreased by 59%, accompanied by a considerable decline in the prevalence of women with BLLs ≥3.5, ≥5.0, and ≥10.0 μg/dL. Despite the encouraging downward trend in BLLs throughout the study period, our data indicate that a considerable number of fetuses continue to be exposed to harmful levels of lead and that lead exposure remains a significant public health challenge in Adjara.