Effects of exercise on blood glucose levels and pregnancy outcomes in women with gestational diabetes mellitus: A meta-analysis and meta-regression

Background Gestational diabetes mellitus (GDM) increases the risk of adverse pregnancy outcomes. Due to variations in exercise protocols, the effects of exercise on GDM remain inconsistent. This review aims to explore the effects of exercise on maternal and neonatal outcomes in women with GDM, and whether there is a dose-response relationship between exercise volume and pregnancy outcomes. Methods PubMed, Embase, Web of Science, EBSCO, ScienceDirect, Cochrane Library, China National Knowledge Infrastructure, WanFang Data, and VIP Chinese Science and Technology Periodicals Full-Text Databases were searched for randomized controlled trials. Cochrane RevMan and R were used for statistical analysis, and studies were evaluated using the Cochrane Risk of Bias Assessment Tool. Weighted-mean standardized mean differences were calculated using a random effects model. Heterogeneity was evaluated using I 2 . Results Twenty-four studies and 3,477 participants were included. Results from meta-analysis showed that exercise significantly lowered fasting blood glucose (FBG) (SMD = −1.69, I 2 = 96 %, p < 0.0001), 2-h postprandial blood glucose (2-hPBG) (SMD = −2.10, I 2 = 96 %, p < 0.0001), and glycated hemoglobin (MD = −0.95, I 2 = 98 %, p < 0.0001) and reduced the risk of gestational hypertension (RR = 0.24, I 2 = 0 %, p < 0.0001) and cesarean section (RR = 0.71, I 2 = 53 %, p = 0.0005), preterm birth (RR = 0.51, I 2 = 31 %, p = 0.002), macrosomia (RR = 0.40, I 2 = 19 %, p < 0.0001), and neonatal hypoglycemia (RR = 0.49, I 2 = 0 %, p = 0.03). Subgroup analyses indicated that moderate combined aerobic and resistance exercise improved FBG (SMD = −2.39, I 2 = 98 %, p < 0.0001), 2-hPBG (SMD = −2.96, I 2 = 97 %, p < 0.0001) and reduced the risks of cesarean section (RR = 0.68, I 2 = 40 %, p = 0.02), preterm birth (RR = 0.46, I 2 = 23 %, p = 0.01) and macrosomia (RR = 0.27, I 2 = 0 %, p < 0.0001). In addition, the meta-regression analysis demonstrated a significant dose-response relationship between exercise volume and 2-hPBG ( β = −0.004, I 2 = 36.9 %, p = 0.002). Conclusions Moderate-intensity combined aerobic and resistance exercise, performed for at least 30 min per session on more than three days per week for at least six weeks, is associated with more pronounced improvements in glycemic control in women with GDM. It also reduces the risk of cesarean section, preterm birth, and macrosomia. These findings underscore the importance of optimizing exercise prescriptions to enhance both maternal and neonatal health. Registration number for clinical trials PROSPERO (CRD42021286338).