BackgroundThesolute carrier family 30 A8 zinc transporter(SLC30A8) plays a crucial role in insulin secretion. This study aimed to investigate the impact ofSLC30A8gene polymorphisms on gestational diabetes mellitus (GDM).MethodsThe research objective was to select 500 patients with GDM and 502 control subjects. Rs13266634 and rs2466293 were genotyped using the SNPscan™ genotyping assay. Statistical tests, such as the chi-square test, t-test, logistic regression, ANOVA, and meta-analysis, were conducted to determine the differences in genotypes, alleles, and their associations with GDM risk.ResultsStatistically significant differences were observed in age, pregestational BMI, SBP, DBP, and parity between individuals with GDM and healthy subjects (P< 0.05). After adjusting for these factors, rs2466293 remained significantly associated with an increased risk of GDM in overall subjects (GG+AG vs. AA: OR = 1.310; 95% CI: 1.005-1.707;P= 0.046, GG vs. AA: OR = 1.523; 95% CI: 1.010-2.298;P= 0.045 and G vs. A: OR = 1.249; 95% CI: 1.029-1.516;P= 0.024). Rs13266634 was still found to be significantly associated with a decreased risk of GDM in individuals aged ≥ 30 years (TT vs. CT+CC: OR = 0.615; 95% CI: 0.392-0.966;P= 0.035, TT vs. CC: OR = 0.503; 95% CI: 0.294-0.861;P= 0.012 and T vs. C: OR =0.723; 95% CI: 0.557-0.937;P= 0.014). Additionally, the haplotype CG was found to be associated with a higher risk of GDM (P< 0.05). Furthermore, pregnant women with the CC or CT genotype of rs13266634 exhibited significantly higher mean blood glucose levels than those with the TT genotype (P< 0.05). Our findings were further validated by the results of a meta-analysis.ConclusionTheSLC30A8rs2466293 polymorphism was found to be associated with an increased risk of GDM, while rs13266634 was associated with a decreased risk of GDM in individuals aged ≥ 30 years. These findings provide a theoretical basis for GDM testing.