Comment on “Effectiveness and Safety of Assisted Vaginal Birth and Second-Stage Cesarean Section: A Systematic Review and Meta-Analysis of Real-World Contemporary Data”

Complications during the second stage of labor increase the risks for maternal and neonatal morbidity and mortality. In these situations, clinicians must weigh the risk of continuing with expectant management or expediting birth with assisted vaginal birth (AVB) or second-stage cesarean section (SCS). However, AVB and SCS are also associated with adverse maternal and neonatal outcomes. While AVB is still an important option, its use has been declining due to concerns around increased maternal trauma and neonatal injury. As a result, the rate of SCS has risen. Previous systematic reviews on the efficacy and safety of AVB have been limited because they do not reflect current obstetric practice, changes in maternal demographics, or the variation in clinician experience. The aim of this study was to review the effectiveness and safety of AVB instruments in the second stage of labor.

This was a systematic review of randomized controlled, cross-sectional, and cohort studies published between January 2001 and December 2023. Included were studies that had ≥30 obstetric patients who had an operative procedure using forceps, vacuum extraction, Kiwi vacuum, spatula only, or SCS during the second stage of labor. Also included were studies that reported on at least one of the following outcomes: failure rate of AVB, adverse maternal and neonatal outcomes associated with AVB by instrument type, and adverse maternal outcomes associated with SCS in singleton pregnancies.

A total of 241 studies were included in the analysis, involving 51,242 patients across 48 countries. The AVB failure rate was significantly higher in deliveries using Kiwi vacuum compared to forceps (9.80% vs. 3.26%; P =0.001) or spatula (9.80% vs. 1.62%; P <0.001). The rate of obstetric and sphincter injury was higher in cases involving forceps compared with vacuum extraction (7.99% vs. 4.73%; P =0.008) and Kiwi (7.99% vs. 4.02%; P =0.001). The rate of postpartum hemorrhage was higher for spatula versus vacuum extractions (10.77% vs. 5.46%; P <0.0001) and Kiwi (10.77% vs. 5.45%; P =0.0311). The prevalence of cephalohematoma was higher for vacuum extractions compared to spatula ( P <0.001). Admission to the neonatal care unit was more prevalent in deliveries that used SCS compared to forceps (17.18 vs. 6.64; P <0.0001) and vacuum extractions (17.18 vs. 6.07; P <0.0001).

In conclusion, wide variation was observed in the prevalence of AVB failure, with the lowest failure rates among forceps and spatula use, but the highest OASI in forceps.

(Summarized from Cabrera-Dandy M, Torloni MR, Merialdi M, et al. Effectiveness and safety of assisted vaginal birth and second-stage cesarean section: a systematic review and meta-analysis of real-world contemporary data. Am J Obstet Gynecol . 2026 Feb;234(2):310-320. doi: 10.1016/j.ajog.2025.09.022).