574: Neonatal outcomes after operative vaginal delivery - are forceps or vacuum safer?

Increased operative vaginal delivery (OVD) is advocated in order to decrease rising cesarean rates. Our aim was to compare neonatal morbidity between unassisted, vacuum and forceps vaginal delivery in order to inform OVD decisions. We conducted a population-based retrospective cohort study of all singleton term liveborn infants and their mothers using linked California birth and hospital discharge data, 2008-12. Unassisted vaginal delivery (VD) and vacuum or forceps assisted delivery (VAD and FAD) was determined from the birth certificate. Study outcomes included 5-minute Apgar score < 7, shoulder dystocia, skeletal injury, neurological injury, severe infection, respiratory morbidity, and a composite of all these morbidities with the exception of 5-minute Apgar score. Robust multivariable Poisson models were used to obtain adjusted relative risks of morbidity outcomes for delivery method with VD as the referent. Analysis was stratified by parity (primiparous versus multiparous). Associations were adjusted for maternal demographic, labor, delivery and infant characteristics (see Figure 1) and accounted for clustering of deliveries within hospitals. 1,555,569 total deliveries were included in the cohort, of whom 94.6% occurred by VD, 0.3% by FAD and 5.0% by VAD. Among nulliparous women, the overall composite morbidity was seen in 6.5% for VD, 16.7% for FAD and 13.3% for VAD, and among multiparous women in 4.4% for VD, 12.9% for FAD and 10.5% for VAD (Table 1). After adjusting for possible confounding variables there was no significant difference between composite morbidity between FAD and VAD in either nulliparous or multiparous women, and both were increased when compared to VD (Figure 1). FAD was associated with decreased rates of shoulder dystocia in both nulliparous and multiparous women when compared to VAD, but increased rates of skeletal and neurological injury in nulliparous women only. Deliveries with FAD and VAD had similar risks for composite neonatal morbidity that were also significantly higher than for VD. Deliveries with FAD had less shoulder dystocia when compared with VAD in both nulliparous and multiparous women. Nulliparous women undergoing FAD may represent a higher risk group for neonatal skeletal and neurological injury.View Large Image Figure ViewerDownload Hi-res image Download (PPT)