Maternal and infant complications in high and normal weight infants by method of delivery

To estimate the population risks of maternal and infant complications with the birth of macrosomic (at least 4000 g) compared with normal weight infants.

Term, singleton infants were identified from the state of Washington's birth event records database for 1990. Diagnosis codes from the Internal Classification of Diseases (9th revision) were used to identify delivery method and previously defined complications. We adjusted for maternal demographic and clinical factors using multivariable logistic regression to derive the risk of each maternal and infant complication.

The incidence of macrosomia was 13% (8815 of 66,086). Vaginal birth of macrosomic infants was associated with low incidence of complications except for shoulder dystocia (11%) and postpartum hemorrhage (5%). Postpartum infection was the most common complication for women who had cesarean delivery after labor (5%), and complications for women who had cesarean without labor were rare (less than 3%). Neonatal complications were rare. Among infants with shoulder dystocia, the risks of asphyxia (adjusted relative risk [RR] 1.2, 95% confidence interval [CI] 0.6, 2.3), birth trauma (RR 0.6, 95% CI 0.2, 1.6), long-bone injury (RR 1.2, 95% CI 0.6, 2.4), seizures (RR 1.0, 95% CI 0.0, 25.0), and facial palsy (RR 2.2, 95% CI 0.2, 44.4) were not significantly different for macrosomic and normal weight infants; however, macrosomic infants had a significantly increased risk of Erb palsy (RR 3.5, 95% CI 1.8, 7.5).

This population-based study showed that most macrosomic infants are delivered vaginally with low rates of maternal and neonatal complications. Macrosomic infants have higher rates of Erb palsy, but similar rates of other serious complications of shoulder dystocia when compared with normal weight infants.