Vacuum extraction effective in fetuses with ultrasound-confirmed occiput posterior position, suggests study

3 academic maternity units enrolled singleton pregnancies at term with fetal OP position established by sonography before the vacuum extraction. Transperineal sonography was used to measure the head-perineum distance (HPD) and the angle of progression (AoP) at the fetal head station. The need for a cesarean birth, or failed VE, was the main result.

Negative outcomes for the mother and/or the newborn were secondary outcomes, as was complicated VE, which was defined as failed VE or at least three of the following 6 parameters as neonatal trauma, postpartum hemorrhage, obstetric anal sphincter injuries, neonatal acidemia, admission to the neonatal intensive care unit, and Apgar <7 at 5 minutes.

VE was effective in 94 (96%), out of the 98 patients that were part of the trial. With an area-under-the-curve of 0.79, logistic regression analysis demonstrated that the head-perineum distance (HPD) measurement alone was independently linked with failed VE. Successful and unsuccessful VE were distinguished by an HPD cut-off value of 38.5 mm, which produced a specificity of 84.0% (79/94), sensitivity of 75.0% (3/4), LHR+ of 4.7, and LHR- of 0.3. Overall, this study showed that fetuses with sonographically detected persistent OP position in the second stage of labor had a high VE success rate and a low risk of maternal and fetal complications.

Reference:

Falcone, V., Dall’Asta, A., Romano, A., Mappa, I., Geron, Y., Bontempo, P., Salluce, M., Di Pasquo, E., Morganelli, G., Di Serio, M., Fieni, S., Gilboa, Y., Rizzo, G., & Ghi, T. (2024). Vacuum extraction is successful in 95% of cases with an occiput posterior position: the results of a prospective, multi-center study. In American Journal of Obstetrics and Gynecology. Elsevier BV. https://doi.org/10.1016/j.ajog.2024.12.022