Mode of Delivery in Nulliparous Women and Neonatal Intracranial Injury

Abstract

When a normal spontaneous vaginal delivery cannot be achieved, one of the following 3 modes of assisted delivery is used: forceps-assisted vaginal delivery, vacuum-assisted vaginal delivery, or cesarean delivery. There is evidence that use of assisted delivery may be associated with adverse neonatal complications that affect long-term cognitive outcome. Few studies have compared the frequency of adverse neonatal outcomes according to mode of delivery; moreover, the results of such studies are unclear. Adverse morbidities in neonates most predictive of future neurodevelopmental deficits are intraventricular hemorrhage, subdural hemorrhage, and seizures; when examined collectively, these best predict neurologic outcome. The aim of this study was to compare adverse neonatal neurologic outcomes among infants delivered by cesarean delivery, forceps-assisted vaginal delivery, or vacuum-assisted vaginal delivery. The association between mode of delivery and adverse neonatal outcomes was examined for 1,025,903 singleton live births born at ≥34 weeks' gestation to nulliparous women using New York City birth certificate data and hospital discharge data from 1995 to 2003. Neonatal morbidities assessed included intraventricular hemorrhage, subdural hemorrhage, seizures, scalp injury or cephalohematoma, skeletal fracture, facial nerve palsy, brachial plexus injury, and a 5-minute Apgar score of <7. Multivariable logistic regression was used to assess associations between delivery mode and neonatal morbidities, adjusting for confounding variables. Fewer seizures and 5-minute Apgar scores <7 were associated with forceps-assisted vaginal delivery compared with vacuum-assisted vaginal delivery and cesarean delivery (P < 0.01 for both). The incidence of subdural hemorrhages was lower among neonates delivered by cesarean delivery compared with forceps-assisted vaginal delivery (P < 0.01) or vacuum-assisted vaginal delivery (P < 0.04). However, forceps-assisted vaginal delivery was associated with fewer composite neurologic complications (intraventricular hemorrhage, subdural hemorrhage, and seizure) than either vacuum-assisted vaginal delivery (adjusted odds ratio, 0.60; 95% confidence interval, 0.40–0.90) or cesarean delivery (adjusted odds ratio, 0.68; 95% confidence interval, 0.48–0.97). Number-needed-to-treat analysis showed that to prevent 1 case of severe neurologic morbidity required 509 forceps-assisted vaginal deliveries compared with vacuum-assisted vaginal deliveries and 559 forceps-assisted vaginal deliveries compared with cesarean deliveries. These findings suggest that a forceps-assisted vaginal delivery is associated with a reduced risk of adverse neonatal neurologic outcomes compared with either vacuum-assisted vaginal delivery or cesarean delivery.