The Status of Heavy Metal Contamination in Amniotic Fluid and Meconium in Khulna City, Bangladesh: A Cross-Sectional Study

Background: Lead (Pb) and cadmium (Cd) are known for their detrimental effects on fetal neurodevelopment and endocrine function. The aim of this study is to investigate the presence and transfer of Pb and Cd from maternal amniotic fluid (AF) to neonatal meconium during pregnancy. Methods: AF and meconium samples were collected from 30 mother-newborn pairs in Khulna, Bangladesh and analyzed for Pb and Cd concentrations using atomic absorption spectrophotometry (AAS) equipped with graphite furnace. Results: The results revealed that among 23 pairs of samples Pb was present in 70% of AF samples and 35% of meconium samples, with an average concentration of 14.03 ± 3.02 ppb and 3.78 ± 2.3 ppb, respectively. Besides, Cd was detected in 96% of AF samples and 39% of meconium samples, with an average concentration of 1.01 ± 0.13 ppb and 0.13 ± 0.04 ppb, respectively. We also identified the metal transfer from AF to meconium, denoted as “transfer ratio” and this was calculated by dividing the metal content of meconium with its corresponding AF’s metal content. The transfer ratios of Cd and Pb from AF to meconium varied, with most samples showing no transfer (61% for and 74% for Pb). Among the samples with detectable transfer, the average transfer ratio was 28% for both metals. Transfer patterns were further analyzed based on various demographic factors which is a noble approach but statistically, no correlation was found (p > 0.05). Conclusion: The findings indicate variable transfer of Pb and Cd during pregnancy and highlight the potential risks posed by environmental exposure to these metals like – preeclampsia, impaired neurodevelopment, miscarriage etc. This study will help researchers monitor large cohorts' toxic metal exposure to safeguard maternal and fetal health.