Objective: To evaluate associations between operative vaginal delivery complications and provider experience (operative vaginal delivery volume and time since residency).
Methods: We included all operative vaginal deliveries between 2008 and 2014 at a tertiary care teaching hospital, stratified into forceps-assisted and vacuum-assisted deliveries. Complications included severe perineal lacerations (3rd and 4th degree) and neonatal injuries (subgaleal/subdural/cerebral hemorrhage, facial nerve injury, and scalp injury), which were identified by International Classification Diagnosis-9 codes. Providers were categorized by operative vaginal delivery volume (mean annual forceps- or vacuum-assisted deliveries over the study interval) and time since residency. Regression analyses were used to compare complication rates by provider volume and time since residency, adjusting for potential confounders, using 0-1 deliveries per year and <5 years since residency as reference groups.
Results: Nine hundred and thirty-four forceps and 1074 vacuums occurred. For forceps-assisted deliveries, severe perineal injury was decreased among providers with >10 forceps per year (aOR 0.50 [95%CI 0.30-0.81]) and at 15-19 years (aOR 0.45 [95% CI 0.22-0.94], and ≥25 years (aOR 0.45 [0.27-0.73]) since residency. There were no associations with neonatal injuries. Among vacuum-assisted deliveries, severe perineal injury decreased at ≥25 years since residency (aOR 0.35 [95%CI 0.17-0.74], with no association with provider volume. Neonatal injury decreased at 5-9 years (aOR 0.53 [95%CI 0.30-0.93]), and 15-19 years since residency (aOR 0.53 [95%CI 0.29-0.97]), due to differences in scalp injuries. Neonatal injuries other than scalp injury were rare.
Conclusion: Severe perineal lacerations decreased with increasing operative vaginal delivery experience, primarily among forceps-assisted vaginal delivery. Providers >5 years since residency may have lower scalp injury with vacuums, but this cohort was largely underpowered for neonatal injury.
Keywords: Birth injury; delivery; forceps; lacerations; obstetric; obstetrical; vacuum extraction.