A major concern in managing the third stage of labor (delivery of the placenta and membranes) is to minimize the risk of postpartum hemorrhage. Maternal blood loss of 500 mL (15 oz) or more within 24 hours of delivery is defined as postpartum hemorrhage, and the condition is associated with significant rates of short- and long-term morbidity. The controversy has been complicated by the role of maternal position, which is believed to significantly influence maternal blood loss. Rogers and colleagues compared two approaches to management of the third stage of labor in a large population of women at low risk for postpartum hemorrhage.
The two principal management strategies for the third stage of labor are expectant management (sometimes called conservative management) and active management. Active management protocols include routine administration of a uterotonic drug, early clamping and cutting of the cord, and controlled cord traction. Expectant management depends on expulsion of the placenta through maternal effort and may incorporate early suckling to stimulate natural uterine contractions.
Women with uncomplicated pregnancies and no risk factors for postpartum hemorrhage were invited to join the study between 24 and 32 weeks of gestation. Random allocation of 1,512 participants was achieved by use of sealed envelopes opened only after labor had begun and the likelihood of normal delivery with low risk of postpartum hemorrhage was confirmed. Patients were assigned to one of four strategies: expectant management with upright posture, expectant management with supine posture, active management with upright posture or active management with supine posture. Over 90 percent of women received the form of management assigned. Data were collected about blood loss, postdelivery hemoglobin concentration, use of blood transfusion and iron therapy, and indicators of infant health.
The groups were comparable in all significant variables, and the overall rate of postpartum hemorrhage was 11.7 percent. The 764 mothers in the expectant management group had significantly higher rates of postpartum hemorrhage (126 patients, or 16.5 percent) than the 748 mothers who underwent active management (51 patients, or 6.8 percent). The rate of blood loss in excess of 1,000 mL (30 oz) was also higher in the expectant group, but the difference was not statistically significant.
Mothers in the expectant management group experienced significantly higher rates of other measures of blood loss, such as levels of postnatal hemoglobin less than 10 g per dL (100 g per L), need for blood transfusions and iron medication. This group also was more likely to have a prolonged third stage of labor (greater than 30 minutes) and need for uterotonic medication. The two groups did not differ in the rate of hypertension, but mothers in the expectant group reported less nausea and vomiting. No significant differences in health at six weeks postpartum or in outcomes for the infants were recorded. Analyses of the study data did not find differences in postpartum hemorrhage according to maternal posture.
The authors conclude that active management significantly reduced the risk of postpartum hemorrhage. They calculate the relative risk of postpartum hemorrhage with expectant management to be 2.4, thus active management of 10 mothers would be necessary to prevent one case of postpartum hemorrhage. Furthermore, maternal posture did not contribute significantly to the outcome of third-stage management. They report that many mothers expressed a preference for expectant management and emphasize the importance of individualized decisions based on balancing the risks and advantages of each management strategy.