Blood lead levels in pregnant women and their newborn infants at an Indian teaching hospital

J Family Med Prim Care. 2024 Jan;13(1):348-355. doi: 10.4103/jfmpc.jfmpc_963_23. Epub 2024 Feb 8.

Abstract

Background and aim: With the growth of the world's economy and industrialization, lead (Pb) contamination in the environment has become a major issue on a global scale. Lead is typically linked to unfavorable pregnancy outcomes such as stillbirth, low birth weight preterm, and spontaneous abortion. In this study, we evaluated the blood lead levels of pregnant women and their birth outcomes attending an Indian tertiary care teaching hospital, those who were not exposed to any lead-associated industry or shops.

Methods: A descriptive study was undertaken to evaluate blood lead estimation in pregnant women and umbilical blood lead levels in a community hospital. Blood samples from 104 mothers during the 1st trimester, 90 mothers during 3rd trimester, and from the umbilical cord were collected. Self-administered questionnaires were used to collect information on demographics, medical history, and concerns linked to pregnancy. Following acid digestion, the levels of lead in whole blood were determined by an atomic absorption spectrometer. The DNA damage in high blood lead-concentrated pregnant women was evaluated by comet assay methods.

Results: Among 194 blood samples of pregnant women, 31 (15.98%) samples revealed ≥5 μg/dL blood lead levels. High lead concentration (≥5 µg/dL) in 1st trimester pregnant women, end of 3rd trimester and cord blood were detected 20.19%, 11.11% and 1.11% respectively. The mean blood lead levels in 1st trimester, 3rd trimester, and cord blood were 3.88 ± 3.19, 2.66 ± 1.82, and 1.53 ± 1.06 mg/dL, respectively. The blood lead concentrations were significantly higher in the 1st trimester of pregnancy than in the 3rd trimester of pregnancy (P < 0.0017). A positive correlation between maternal and infant blood lead levels was revealed (P < 0.0001). When the comet assay was used to assess the genotoxic consequences of elevated blood lead levels during pregnancy, higher amounts of DNA damage were found in the samples (P < 0.01).

Conclusion: In this descriptive study, there was a significant amount of lead transferred from mother to baby through the placenta. All mothers were not exposed to lead-associated industry and most were housewives. This article may be viewed as an eye-opener for understanding the blood lead concentration during pregnancy to avoid abnormal birth outcomes. To minimize exposure to environmental lead, all possible measures should be undertaken.

Keywords: Blood lead level; DNA damage; comet assay; lead poisoning; newborn; reproductive toxicity.