Objective: This study aims to investigate the efficacy of continuous oxytocin administration after completion of routine oxytocin administration during the third stage of labor in patients with twin pregnancies delivered via cesarean delivery (CD).
Methods: This retrospective case-control study was conducted between April 2014 and March 2024, and it included 156 women with twin pregnancies. The oxytocin group included patients who were administered continuous oxytocin 2 IU/h until 24 hours after delivery after completion of oxytocin 5 IU intravenous injection immediately after delivery as the routine procedure. The control group included patients who underwent the routine oxytocin procedure only. We conducted overlap propensity score-weighted analyses and inverse probability-weighted analyses in parallel to compare the incidence of postpartum hemorrhage (PPH) and adverse events within 24 hours after CD, including the mean amount of lochia, the incidence of blood transfusion, shock, and additional procedures to control bleeding, and reduction in hemoglobin (Hb) levels and hematocrit (Ht) values before and after CD.
Results: In the overlap propensity score-weighted analysis, the mean amount of lochia within 24 hours after CD, reduction in Hb levels, and reduction in Ht values were significantly lower in the oxytocin versus the control group (177 g and 383 g, respectively; (95% confidence interval (CI), -328.5 to -84.5); P < 0.01, 0.59 g/dL and 1.08 g/dL, respectively; (95% CI, -0.94 to -0.05); P = 0.03, and 1.75% and 3.37%, respectively; (95% CI, -2.94 to -0.29); P = 0.02, respectively). There was no significant difference in the total blood loss within 24 hours after CD and the incidence of any adverse events within 24 hours after CD, such as PPH, shock, additional procedures to control bleeding, and blood transfusion. Although the difference was not significant, the incidence of lochia exceeding 500 g was lower in the oxytocin versus the control group (4.8% and 26.4%, respectively; OR: 0.14 (95% CI, 0.02 to 1.17); P = 0.07). In the inverse probability-weighted analyses, the mean amount of lochia within 24 hours after CD was significantly lower in the oxytocin versus the control group (183 g and 387 g, respectively; (95% CI, -320.2 to -87.8); P < 0.01). Although there was no significant difference in the incidence of blood transfusion, the incidence of lochia exceeding 500 g or 1000 g was significantly lower in the oxytocin versus control group (4.6% and 27.2%, respectively; OR: 0.13 (95% CI, 0.04 to 0.41); P < 0.01, and 1.5% and 12.5%, respectively; OR: 0.10 (95% CI, 0.02 to 0.65); P < 0.01, respectively).
Conclusion: Continuous oxytocin administration after completion of oxytocin administration during the third stage of labor may reduce the incidence of PPH after CD for twin pregnancies.
Keywords: cesarean section (cs); oxytocin regimen; propensity score-matching analysis; twin pregnancy; uterine atony.
Copyright © 2024, Morita et al.