Effect of Exercise Intervention Protocol on Third Stage of Labor during Third Trimester of Singleton Gravid: A Quasi Experimental Randomized Trial

Abstract

Background: Maternal morbidity and mortality remain major public health challenges, particularly in low-resource settings where complications during labor account for a significant proportion of maternal deaths. The third stage of labor, involving placental separation and expulsion, is often underemphasized in research despite being directly associated with postpartum hemorrhage, the leading cause of maternal death globally. Evidence suggests that antenatal exercise improves maternal cardiovascular efficiency and uterine contractility, but its effects on third-stage labor outcomes remain underexplored. Objective: To evaluate the effect of an eight-week moderate-intensity exercise intervention during the third trimester on the duration and mode of management of the third stage of labor among singleton gravid women. Methods: A quasi-experimental randomized trial was conducted at a Basic Health Unit in Rawalpindi, Pakistan. Eighteen primigravida women were recruited and randomly allocated to intervention (n=10) and control (n=8) groups. The intervention group performed a structured exercise protocol, while controls received routine antenatal care. Primary outcomes were the duration of the third stage of labor and physiological versus active management. Statistical analyses included independent-samples t-tests and chi-square tests, with p<0.05 considered significant. Results: The intervention group had a significantly shorter mean duration of third-stage labor compared with controls (11.3 ± 4.3 vs. 23.8 ± 4.8 min; mean difference -12.45, 95% CI -17.01 to -7.89, p<0.001, Cohen’s d=2.63). Physiological management was more frequent in the intervention group (60.0% vs. 37.5%), though the difference was not statistically significant (OR 2.50, 95% CI 0.40–15.56). Conclusion: Third-trimester exercise significantly reduced the duration of the third stage of labor and showed a favorable, though non-significant, trend toward increased physiological management. Exercise interventions represent a low-cost, non-pharmacological strategy with potential to improve maternal outcomes, warranting further validation in larger trials.