A meta-analysis based on epidemiological studies to identify the key environmental pollutants inducing gestational...

Exposure to environmental pollutants intricately contributes to the incidence of gestational diabetes mellitus (GDM), thus it is imperative to identify the key contaminants which may induce GDM risk in humans. Herein, we conducted a systematic review and meta-analysis on a total of 112 epidemiological studies to clarify the environmental risk factors for GDM occurrence. A total of 10 air pollutants, 26 metal elements, and 8 categories of organic compounds were examined. Fixed- and random-effect models were used to calculate the pooled odds ratio and 95 % confidence interval for evaluating the effects of contaminants. The results showed that exposure to air pollutants significantly increased GDM risk, with black carbon, PM_2.5, PM₁₀, carbon monoxide, nitric oxide, nitrogen oxides, and sulfur dioxide identified as potential risk factors (p < 0.05). There was a markedly positive relationship between metal exposure and GDM risk, with aluminum, antimony, mercury, and rubidium contributing significantly to GDM incidence (p < 0.05). Higher exposure to organic compounds was also associated with a greater risk of GDM, with polybrominated diphenyl ethers, per- and poly-fluoroalkyl substances (PFAS), phthalates, polychlorinated biphenyls, and organophosphate esters making significant contributions (p < 0.05). Several specific homologues were identified to make a dominant contribution within each class of these organic chemicals, such as perfluorooctanoic acid (36.54 %) and perfluorononanoic acid (32.09 %), which were the most risky PFAS compounds. These findings provide a critical insight into the etiology of GDM and may inform strategies to protect against pregnancy complications.