[Delivery management for the prevention of shoulder dystocia in case of identified risk factors].

OBJECTIVE: To determine the impact of (i) computed tomographic (CT) pelvimetry for the choice of the mode of delivery, (ii) cesarean, (iii) induction of labor, and of (iv) various delivery managements on the risk of shoulder dystocia in case of fetal macrosomia, with or without maternal diabetes, and in women with previous history of shoulder dystocia.

METHODS: The PubMed database, the Cochrane Library and the recommendations from the French and foreign obstetrical societies or colleges have been consulted.

RESULTS: In case of clinically suspected macrosomia, a sonography should be performed to increase diagnostic performances and to assist in decision-making (Professional consensus). Because CT pelvimetry is associated with high false positive rates and increases cesarean deliveries, its use is not recommended to prevent shoulder dystocia in case of fetal macrosomia (Professional consensus). To avoid the neonatal complications of shoulder dystocia, mainly permanent brachial plexus palsy, cesarean delivery is recommended in case of estimated fetal weight (EFW) greater than 4500 g if associated with maternal diabetes (grade C), and greater than 5000 g in the absence of maternal diabetes (grade C). The published data do not provide definitive evidences to recommend systematic labor induction in case of impending fetal macrosomia (Professional consensus). In case of favourable cervix and gestational age greater than 39 weeks of gestation, labor induction should be promoted (Professional consensus). Prophylactic McRoberts maneuver is not recommended to prevent shoulder dystocia in case of fetal macrosomia (grade C). Because data are lacking, no recommendation is possible regarding the use of episiotomy. In case of fetal macrosomia and failure to progress in the second stage of labor, midpelvic and higher instrumental deliveries are not recommended and a cesarean delivery should be preferred (grade C), if the fetal head is at or lower than a +2 station, cesarean delivery is not recommended and an instrumental delivery should be preferred (grade C). Finally, cesarean delivery should be discussed when history of shoulder dystocia has been associated with severe neonatal or maternal complications (Professional consensus).

CONCLUSION: To avoid shoulder dystocia and its complications, only two measures are proposed. Induction of labor is recommended in case of impending macrosomia if the cervix is favourable and gestational age greater than 39 weeks of gestation (Professional consensus). Cesarean delivery is recommended before labor in case of (i) EFW greater than 4500 g if associated with maternal diabetes (grade C), (ii) EFW greater than 5000 g in the absence of maternal diabetes (grade C), and finally (iii) during labor, in case of fetal macrosomia and failure to progress in the second stage, when the fetal head is above a +2 station (grade C). Finally, cesarean delivery should be discussed when history of shoulder dystocia has been associated with severe neonatal or maternal complications (Professional consensus).