Abstract
Background: Obesity during pregnancy increases the risk of adverse maternal and neonatal outcomes, and excessive gestational weight gain (GWG) remains highly prevalent worldwide. Although physical activity (PA) interventions have shown potential benefits, evidence on the optimal type, intensity, and duration of exercise for overweight or obese pregnant women remains limited. Methods: Electronic searches of EBSCOhost, Embase, PubMed and Web of Science were performed through August 2025 to identify randomized controlled trials comparing PA interventions versus usual prenatal care in overweight or obese pregnant women. Two reviewers independently screened studies, extracted data, and assessed risk of bias using Cochrane ROB domains. Continuous outcomes were pooled using inverse-variance meta-analytic methods and heterogeneity was quantified by I(2). Results: Ten randomized trials (twelve intervention arms) comprising 1150 participants met the inclusion criteria. In the domain of blinding of participants and personnel, three studies (30%) were judged as low risk, while seven (70%) were unclear. PA interventions varied in modality (aerobic, resistance, endurance, walking), setting (clinic, community, home/mHealth), and the intervention period ranges from 10 to 34 weeks. Most interventions (80%) employed moderate intensity, and 30% combined aerobic and resistance training. Results of the meta-analysis showed that the pooled mean GWG was 9.93 ± 5.48 kg in the treatment group and 10.65 ± 5.70 kg in the control group. Overall, PA interventions produced a modest but statistically significant reduction in GWG compared with controls, with negligible between-study heterogeneity (I(2) = 0%). Conclusions: Tailored, moderate-intensity PA may have the potential to modestly reduce GWG. Although 30% included trials employed combined aerobic and resistance training, current evidence is insufficient to establish whether combined modalities are more effective than aerobic-only or resistance-only interventions. However, the current evidence is limited by small trial sizes, methodological variability and geographic concentration in higher-income settings. Larger, rigorously designed RCTs, including evaluations of digital delivery platforms and carefully supervised higher-intensity protocols, are needed to refine exercise prescriptions and inform clinical guidelines.