Objective To systematically review the association between periodontal disease during pregnancy and the risk of gestational diabetes mellitus (GDM). Methods PubMed, Web of Science, CBM and CNKI databases were electronically searched to collect studies on periodontal disease and GDM from inception to October 23, 2021. Two researchers independently screened literature, extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.4 software. Results A total of 11 studies were included, involving 2 910 pregnant women. The results of meta-analysis showed that pregnant women with periodontal disease during pregnancy reported more GDM than normal pregnant women (OR=1.81, 95%CI 1.31 to 2.50, P=0.000 3). Conclusion The current evidence suggests that there is a positive association between periodontal disease during pregnancy and the risk of GDM. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.