BACKGROUND AND PURPOSE:

• Miller et al. (American Journal of Perinatology, 2019) examined whether the number of vacuum pop-offs, forceps pulls, or duration of attempted operative vaginal delivery was associated with adverse fetal or maternal outcomes

METHODS:

• Secondary analysis of a multicenter observational cohort study
  • NICHD MFMU abstracted data between 2008-2011
  • Pregnancies >23 weeks
  • 115,502 women | 25 hospitals
• Participants
  • Women who underwent OVD
• Women were stratified by
  • Duration of OVD (0-2, 3-5, 6-8, 9-11, ≥12 minutes)
  • Number of vacuum pop-offs or forceps pulls (0, 1, 2, ≥3)
• Primary outcomes
  • Severe perineal lacerations
  • Failed OVD
  • Composite adverse neonatal outcome

RESULTS:

• 5,325 women underwent an attempt at OVD
  • Vacuum: 67.5% | Forceps: 32.5%
• Median duration
  • Vacuum: 4 minutes (interquartile range: 2–7 minutes)
  • Forceps: 4 minutes (interquartile range: 2–6 minutes)
• Attempted vacuum
  • Number of pop-offs and duration of procedure both associated with
    • Failed OVD | Severe perineal lacerations | Adverse neonatal outcomes
  • However, duration was more strongly correlated with adverse outcome than number of pop-offs
• Attempted forceps
  • Number of pulls
    • Associated with: Failed OVD | Severe perineal lacerations
    • Not associated with: Composite neonatal adverse outcome
  • Duration of forceps
    • Associated with: Failed OVD | Severe perineal lacerations | Adverse neonatal outcomes
• Increasing minutes of OVD was associated with composite adverse neonatal outcomes
  • Vacuum: Adjusted odds ratio [aOR] 1.09 (95% CI, 1.03–1.16)
  • Forceps: aOR 1.13 (95% CI, 1.03–1.24)
  • No association with fetal station or indication

CONCLUSION:

• While an increased number of vacuum pop-offs or forceps pulls may be associated with adverse neonatal outcomes, duration of OVD attempt is more highly associated with adverse neonatal outcomes
• Authors note that
  • This study evaluates association and not causation
  • Does not provide evidence that cesarean would result in better outcomes

Learn More – Primary Sources:

Duration of Operative Vaginal Delivery and Adverse Obstetric Outcomes

Related ObG Topics: