ABSTRACT
BACKGROUND: There is a lack of evidence related to physical activity and risk of cesarean section (CS) by age and/or weight in pregnant women. OBJECTIVES: To evaluate the effect of physical activity on the incidence of CS and explore the relationship of age and body mass index (BMI) with incidence of CS. SEARCH STRATEGY: A systematic search was conducted in CNKI, WANGFANG, Web of Science, and PubMed from inception to 31 August 2021. SELECTION CRITERIA: Experimental studies were included if the participants were pregnant, if intervention included physical activity and controls received routine prenatal care only, and if primary outcome was CS. DATA COLLECTION AND ANALYSIS: Meta-analysis included a heterogeneity test, data combination, subgroup analysis, forest plot, sensitivity analysis, and dose-response regression analysis. MAIN RESULTS: Sixty-two studies were included. Physical activity during pregnancy decreased the incidence of CS (relative risk [RR] 0.81, 95% confidence interval [CI] 0.74-0.88, P < 0.001). The incidence of CS was lower among the overweight/obese group (RR 0.78, 95% CI 0.65-0.93) compared with the normal weight group (RR 0.82, 95% CI 0.74-0.90). The incidence of CS was lowest among the young age group (RR 0.61, 95% CI 0.46-0.80) compared with the middle age group (RR 0.74, 95% CI 0.64-0.85) and the older age group (RR 0.90, 95% CI 0.82-1.00). The critical value, when age becomes a risk factor for CS, was 31.7 years in the intervention group and 28.5 years in the control group. CONCLUSIONS: Physical activity during pregnancy can reduce the incidence of CS, especially among obese people, and prolong the gestational age span.
