The effect of placental removal method on the incidence of postcesarean infections.

OBJECTIVE: Our purpose was to determine whether the incidence of postoperative endometritis and wound infection is associated with the method of placental removal at the time of cesarean section.

STUDY DESIGN: Parturients undergoing cesarean delivery were prospectively randomized to have the placenta removed manually or spontaneously. Patients were excluded from participation if they had received intrapartum prophylactic antibiotics or had been determined to have chorioamnionitis. After delivery of the infant women in the manual group had the placenta extracted by the primary surgeon, whereas women in the spontaneous group had the placenta delivered by gentle traction on the umbilical cord. All study subjects received perioperative prophylactic antibiotics. The primary outcome variable was a postcesarean infection, defined as postecsarean endometritis or wound cellulitis requiring drainage and antibiotic therapy.

RESULTS: A total of 333 women were enrolled in the investigation, with 165 assigned to the manual removal group and 168 allocated to have spontaneous removal. There were no statistically significant differences in mean gestational age, frequency or duration of ruptured membranes, frequency or duration of labor, or mean number of vaginal examinations between the two study groups. Postoperative infections occurred in 25 of 168 (15%) women in the spontaneous delivery group compared with 44 of 165 (27%) women in which the placenta was manually extracted (relative risk 0.6, 95% confidence interval 0.4 to 0.9, p = 0.01). Subset analysis of patients delivered with ruptured membranes similarly demonstrated a statistically significant reduction in the incidence of postoperative infections with spontaneous placental removal compared with manual extraction (20% vs. 38%, relative risk 0.5, 95% confidence interval 0.3 to 0.9, p = 0.02). There was a similar trend toward a reduction in postdelivery infections associated with spontaneous placental removal in women with intact membranes; however, this difference did not attain statistical significance.

CONCLUSIONS: Spontaneous delivery of the placenta after cesarean delivery is associated with a decrease in the incidence of postcesarean infections.