Mercury exposure, but not lead, increases risk of gestational diabetes mellitus: a meta-analysis.

Gestational diabetes mellitus (GDM) is a growing health problem causing a higher risk of delivering large infants and experiencing maternal and neonatal mortality. Studies have found a link between increased levels of mercury (Hg) and lead (Pb) in the blood and a higher risk of developing GDM. However, there are other reports contradicting the aforementioned findings. In this meta-analysis, we investigated the association between exposure to Hg and Pb and the elevated risk of being diagnosed with GDM. To that end, a systematic search was performed through Google Scholar, Web of Science, PubMed, and Scopus, from inception to May 01, 2024, to gather relevant studies. The association between maternal Hg and Pb exposure and the potential risks of GDM was evaluated through the use of pooled odds ratios (OR) and the corresponding 95% confidence intervals (CI). To make the calculations, the fixed-effects or random-effects models were also applied. Overall, 8 eligible studies met the inclusion criteria and were included in our meta-analysis. The results of our meta-analysis revealed that maternal Hg exposure increases the risk of GDM 1.27 times, which is statistically significant (OR = 1.27, 95% CI =1.10-1.46). Conversely, no significant association was observed between Pb levels and GDM. In conclusion, results showed that Hg exposure, unlike Pb, markedly gave rise to higher risks of GDM.