The impact of mild fundal pressure during vacuum extraction on labor and perinatal outcome

OBJECTIVE: Failed vacuum extraction (VE) is associated with increased adverse maternal and neonatal outcomes. Mild fundal pressure (MFP) is sometimes applied during VE to assist vaginal delivery and to potentially lower the VE failure rate. We aimed to determine whether the addition of MFP during VE reduces failure rates and its impact on perinatal outcomes. METHODS: This was a retrospective study at a single tertiary medical center (January 2022 to March 2024). All term singleton VEs were included and stratified by whether or not MFP was applied. MFP was added at the physician's discretion when initial traction was insufficient to achieve adequate fetal descent. The primary outcome was the rate of failed VE and subsequent cesarean delivery. Secondary outcomes included composite maternal adverse events (obstetric anal sphincter injury, shoulder dystocia, postpartum hemorrhage, or hemoglobin drop ≥3 g/dL) and composite neonatal adverse events (neonatal intensive care unit admission, Apgar score <7 at 5 min, umbilical artery pH <7.1, or birth trauma). RESULTS: Of 2015 VEs, 555 (27.5%) included MFP. Extraction failed in 0.2% with MFP versus 2.2% without (adjusted odds ratio [aOR] 0.08; 95% confidence interval [CI] 0.01-0.61, P = 0.014). Composite maternal outcomes were similar between the groups (19.5% vs. 18.3%; aOR 1.02; 95% CI 0.79-1.32). No difference in composite neonatal outcome was observed (15.7% vs. 12.9%; aOR 1.28; 95% CI 0.97-1.69). CONCLUSION: The application of MFP during VE was associated with reduced failure of operative vaginal delivery without significantly increased maternal or neonatal morbidity.