Placental cord drainage impact on third stage of labor: a randomized controlled trial

Background: The third stage of labor is a pivotal phase in obstetric care. Management may be physiological or active. Although the use of prophylactic placental cord drainage has been assessed in prior data, there is still no clear-cut evidence supporting its effectiveness in improving key obstetric outcomes.

Objective: The aim of the study was to investigate the impact of placental cord drainage during the third stage of labor on the amount of maternal bleeding, duration of the third stage, and incidence of postpartum hemorrhage.

Study design: A randomized controlled trial was conducted at a high-volume tertiary obstetric center between May 2021 and December 2022. A total of 212 pregnant women with a singleton uncomplicated pregnancy were randomly assigned to undergo placental cord drainage or standard care without drainage. The randomization was manual, using premarked cards drawn by the participants. The power calculation determined a sample size of 92 participants per group to achieve 80% power at a 5% significance level, aiming to detect 20% difference in bleeding amount between the groups. In practice, we included more than 100 women in each group. The primary outcome was the amount of bleeding during the third stage of labor, while secondary outcomes included the duration of the third stage and incidence of postpartum hemorrhage. After delivery, all participants received 10 units of oxytocin via intravenous drip, and delayed cord clamping was performed. In the study group, the maternal umbilical cord was then unclamped. Blood was allowed to drain into a plastic bag placed under the women's buttocks. If an episiotomy or perineal tear was observed, pressure packing was applied to reduce bleeding. The collected blood was measured in milliliters after placental expulsion.

Results: A total of 212 women were recruited of whom 104 underwent placental cord drainage and 108 received standard care without drainage. No significant differences were observed between the intervention and control groups in mean duration of the third stage of labor (10.56±6.12 vs 10.95±6.33 minutes, P=.65), incidence of postpartum hemorrhage (3.84% vs 7.41%, P=.38), or mean amount of bleeding during the third stage of labor (292±200 vs 300±242 mL, P=.79). Furthermore, there were no significant between-group differences in the mean amount of bleeding on separate analysis of nulliparous women (356±246 vs 330±240 mL, P=.68), multiparous women (265±171 vs 289±244 mL, P=.50), women who were not exposed to external oxytocin during labor (287±204 vs 317±250 mL, P=.59), and women who were exposed to external oxytocin (296±198 vs 289±238 mL, P=.39).

Conclusion: Placental cord drainage during the third stage of labor showed no statistically significant impact on bleeding amount, third-stage length, or postpartum hemorrhage rate. The findings suggest that placental cord drainage may not offer additional benefits in preventing postpartum hemorrhage in women with uncomplicated pregnancies.