The most common causes of postpartum hemorrhage are uterine relaxation and atony. In the United States, delivery of the placenta is usually followed by intravenous administration of oxytocin to contract the uterus and prevent further bleeding. In Canada, however, active management of the third stage of labor is more commonly practiced, and oxytocin is administered before the placenta is delivered. Khan and associates compared the occurrence of postpartum hemorrhage with controlled cord traction and the occurrence with minimal intervention for delivery of the placenta.
A total of 1,648 women were randomly assigned during labor to receive controlled cord traction (827 patients) or minimal intervention (821 patients) for delivery of the placenta. Patients in the controlled cord traction group received oxytocin, 10 U intramuscularly, at the time of delivery of the anterior shoulder, after which the placenta was delivered by controlled cord traction. In the minimal intervention group, the placenta was delivered by maternal pushing, and no traction was applied to the cord. Continuous intravenous oxytocin was administered after placental delivery.
The incidence of overall postpartum hemorrhage (defined as more than 500 mL) or hemorrhage of more than 1,000 mL was significantly lower in the controlled cord traction group. The median blood loss was 200 mL in the controlled cord traction group, compared with 250 mL in the minimal intervention group. The incidence of placenta retained for longer than 30 minutes was significantly lower in the controlled traction group. Twelve patients (1.5 percent) in this group had retained placenta, compared with 37 patients (4.5 percent) in the minimal intervention group. Four patients in the minimal intervention group and one patient in the controlled cord traction group required blood transfusion. Significantly more patients in the minimal intervention group (42 patients versus 19 patients) required ergot or prostaglandin to control blood loss.
The authors conclude that the controlled cord traction technique for third-stage management is associated with a significantly lower incidence of postpartum hemorrhage compared with minimal intervention. They note some concern that the administration of intramuscular oxytocin before delivery of an undiagnosed twin gestation would compromise delivery of the second twin. In this study, prenatal ultrasonographic examination was performed in all of the patients. When ultrasound assessment is not routinely performed prenatally, administration of oxytocin before delivery of the placenta and controlled cord traction would be a concern. The authors agree with previous studies showing that active management of the third stage of labor by means of controlled cord traction is highly effective in preventing postpartum hemorrhage.
editor's note: The Cochrane review of the childbirth literature reaffirmed the value of active management of the third stage of labor to reduce or prevent postpartum hemorrhage. The studies examined by the Cochrane reviewers showed good consistency and randomization, and demonstrated the effectiveness of this method in reducing postpartum hemorrhage.—b.a.