Sonographic assessment of occiput position does not affect failed operative vaginal delivery rate

Reference

Bellussi F, Di Mascio D, Salsi G, et al. Sonographic knowledge of occiput position to decrease failed operative vaginal delivery: a systematic review and meta-analysis of randomized controlled trials. Am J Obstet Gynecol 2022;226(4):499-509.

Synopsis

These authors conducted a meta-analysis of randomized controlled trials (N = 4; 1007 participants) that tested the hypothesis that more accurate determination of fetal occiput position by ultrasound, as compared with digital vaginal examination, would reduce the failure rate of operative vaginal delivery (OVD). Failed OVD was defined as cesarean delivery or sequential use of different instruments for OVD. The authors included studies that were truly randomized and compared ultrasound evaluation of occiput position during second stage of labor, after randomization and before OVD, to digital vaginal evaluation (control). They evaluated risk of bias according to 7 criteria as prescribed by the Cochrane Handbook for Systematic Reviews of Interventions and found low risk of bias regarding randomization. No study included masking of the women or their birth attendants. Studies were similar in rates of use of epidural analgesia, induction of labor, use of oxytocin, fetal head at station of at least +2, and occiput posterior or transverse. There was no significant difference between sonographic and manual examination groups for rate of OVD failure (9.9% vs 8.2%; relative risk 1.14; 95% CI 0.77 - 1.68). Similarly, there were no differences in secondary outcomes including cesarean delivery, maternal sphincter injuries, shoulder dystocia, the rate of neonatal intensive care admissions, Apgar score of less than 7 at 5 minutes, neonatal trauma, umbilical cord pH less than 7.0, or a composite adverse perinatal outcome.