DATA SOURCES: A comprehensive literature search was carried out via PubMed, Cochrane, Embase and Virtual health libraries till April 2024. Articles with full text were selected in English, Spanish, French, and Portuguese language. Only observational studies were included. STUDY SELECTION: All selected studies were observational in nature and published in full text in English, Spanish, French, or Portuguese language. Gestational diabetes mellitus was diagnosed based on the American Diabetes Association's guidelines, and periodontal disease was diagnosed using international criteria by expert personnel. DATA EXTRACTION AND SYNTHESIS: Two examiners did data extraction and synthesis. To identify the relationship between periodontal disease and gestational diabetes mellitus, an Odds ratio with 95% confidence interval was used. The inverse of the variance fixed effects model was applied. The Der Simonian and Laird random effects model was used if the homogeneity test using the Q statistic and the I2 revealed heterogeneity (p <
0.1). Eggers's test was used for bias assessment, and a funnel plot was also used to determine publication bias. Newcastle -Ottawa criteria were used to evaluate the quality of the included studies. Stata 17 was used in the entire data extraction process. Later on, a meta-analysis was done with seven articles with an adjusted Odds ratio. RESULTS: A total of 187 studies were found after a literature search, later on, duplicates were removed, leaving behind 176 studies. After screening the articles based on inclusion and exclusion criteria, 11 articles were finally included in the systematic review. Out of 11 included studies, 3 studies were cohort studies, and 8 were case-control. A total of 2032 patients were evaluated, out of which 572 developed gestational diabetes mellitus. 10 studies were considered to be of high quality, and one study was of intermediate quality. Six of the eleven studies reported a link between periodontal disease and gestational diabetes mellitus, whereas five did not yield any meaningful findings. The results showed a statistically significant p-value of less than 0.0027 and an odds ratio (OR) of 1.83 with a 95% confidence interval (CI) of 1.25 to 2.69. CONCLUSION: This systematic review and meta-analysis suggest that periodontal disease is related to gestational diabetes mellitus. Several studies support the hypothesis that the presence of periodontal disease increases the risk of the development of gestational diabetes mellitus, more strong evidence is required before the same is established inconclusively.