Fetal macrosomia (> or =4500 g): perinatal outcome of 231 cases according to the mode of delivery.

Objective: To determine perinatal complications in infants >or = 4500 g according to delivery mode.

Study Design: Records of 231 mothers and live cephalic infants weighing >or = 4500 g over a 13-year period were retrospectively reviewed. Maternal and perinatal complications were compared in relation to delivery mode.

Results: Vaginal delivery (NVD) was achievable in 168/189 (88.9%) of women allowed to labor, of which 36.9% were operative. The cesarean delivery (CS) rate was 27.3%. The NVD group had a lower incidence of diabetes; however, hypoglycemia and transient tachypnea were more common in the CS group. The frequency of low Apgar scores at 1 and 5 minutes was similar in both groups. A total of 13 (7.7%) major fetal injuries were documented in the NVD group (arm weakness 3, hematoma 3, clavicular fracture 2, and brachial plexus injury 5). Shoulder dystocia was documented in only 7/13 (53.8%).

Conclusion: Vaginal delivery is achievable in 88.9% of pregnancies with infants >or = 4500 g allowed to labor, at the expense of a 7.7% risk of perinatal trauma.