Oxytocin 'Reasonable' for Placental Management


SAN DIEGO — A single dose of intramuscular oxytocin achieved a significant reduction in the rate of placental retention in second-trimester medical termination, and was associated with a significant reduction in postpartum blood loss, results from a randomized, single-center study showed.

“Intramuscular oxytocin is a reasonable choice as a prophylactic ecbolic for the third stage [of labor] following second-trimester medical pregnancy termination,” Dr. Jan E. Dickinson said at the annual meeting of the Society for Maternal-Fetal Medicine.

Placental retention is a frequent complication of prostaglandin pregnancy termination, occurring 30%-40% of the time, said Dr. Dickinson, associate professor of maternal-fetal medicine at the University of Western Australia School of Women's and Infants' Health, Crawley. Potential complications of placental retention include increased blood loss, infectious morbidity, operative complications, and increased requirement for blood transfusion.

However, current protocols for third-stage management vary, so she and her associates conducted a study intended to develop a third-stage management protocol that would minimize the incidence of placental retention and associated complications among 251 women undergoing pregnancy termination at the university with intravaginal misoprostol at 14–24 weeks. They randomized the women to one of three management strategies: 83 women to receive 10 units of intramuscular oxytocin after delivery of the fetus (group 1); 83 women to receive 600 mcg oral misoprostol after delivery of the fetus (group 2); and 85 women to receive no additional medication after delivery of the fetus (group 3).

The primary outcome was incidence of failure of placental expulsion within 60 minutes of fetal delivery, with the need for operative removal.

Dr. Dickinson, who had no conflicts to disclose, reported that there were no significant differences between the three groups in terms of maternal age (mean, 31 years), race (93% white), parity (mean, one), prior uterine surgery (mean, 20%), median gestational age at study recruitment (19 weeks), or duration of termination (mean, 17 hours). The researchers did observe a significant difference between the groups in the incidence of placental retention (10% in group 1, 29% in group 2, and 31% in group 3). Logistic regression analysis of placental retention rates revealed that the odds ratio between groups 1 and 3 was significant (OR, 0.24), but between groups 2 and 3 it was not (OR, 0.92). Calculated blood loss was significantly lower in group 1 compared with the other groups (100 mL vs. 200 mL in groups 2 and 3). There were no significant differences among groups 1, 2, and 3 in terms of duration of hospital stay (30 hours, 33 hours, and 29 hours, respectively), readmission (7%, 4%, and 9%), or need for curettage (4%, 2%, and 6%).

In a later interview, Dr. Dickinson said that for centers and countries with limited access to hospital facilities, this protocol “potentially offers a simple and effective means to management of the third stage and improved safety for women with pregnancy loss in the second trimester.”

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