The American College of Obstetricians and Gynecologists (ACOG) has issued recommendations on the management of shoulder dystocia (ACOG Practice Pattern no. 7, 1997). The purpose of the document is to provide physicians with clinically useful information derived from a review of studies regarding the prediction, prevention and management of deliveries complicated by shoulder dystocia.
According to ACOG, shoulder dystocia is an obstetric emergency that places both the woman and the fetus at risk of injury. The incidence of shoulder dystocia ranges from less than 1 percent to a little over 4 percent among vaginal cephalic deliveries. Prevention is the best strategy in the management of shoulder dystocia. If fetuses at risk of shoulder dystocia are identified early, elective cesarean delivery can be planned. However, identifying risk factors is not always possible.
ACOG reports that macrosomia and maternal diabetes appear to be the two risk factors most often associated with shoulder dystocia. However, a large number of cases occur among women who do not have diabetes and among infants with birth weights of less than 4,000 g (8 lb, 13 oz). ACOG emphasizes that there is no accurate method for identifying which fetuses will have shoulder dystocia and that performing cesarean deliveries for all women suspected of carrying a macrosomic fetus is not appropriate. ACOG does believe that planned delivery may be a reasonable strategy for pregnant women with diabetes who have estimated fetal weights exceeding 4,250 g (9 lb, 6 oz) to 4,500 g (9 lb, 15 oz).
ACOG notes that injuries may occur to the fetus despite application of appropriate standard obstetric maneuvers. The most common injuries associated with shoulder dystocia are brachial plexus injuries, fractures of the humerus and fractures of the clavicle.
No single maneuver appears to be significantly better than another in releasing an impacted shoulder or reducing the chance of injury. However, the successful use of the McRoberts maneuver has been well documented in the scientific literature. This maneuver involves sharply flexing the patient's legs against her abdomen. In contrast, traction combined with fundal pressure has been associated with a high rate of brachial plexus injuries and fractures.
Practice Patterns are clinical practice guidelines developed by ACOG. More information on ACOG practice patterns, committee opinions, technical bulletins, and criteria sets may be obtained by contacting ACOG, 409 12 St., S.W., P.O. Box 96920, Washington, D.C. 20090; telephone: 800-762-2264.