Assisted Vaginal Birth: New Review Reveals Outcome Gaps

Assisted Vaginal Birth Outcome Reporting in Modern Obstetrics

Obstetricians worldwide rely on assisted vaginal birth to manage prolonged labor and acute fetal compromise. However, clinical studies report procedural success and complications with considerable variation. Therefore, a comprehensive systematic review examined 206 contemporary studies published between 2001 and 2025. The investigators cataloged 2 procedural, 40 maternal, and 53 neonatal outcomes across diverse healthcare settings. Notably, researchers identified significant inconsistency in outcome definitions throughout the medical literature. Furthermore, the majority of evaluated outcomes appeared in fewer than 20 publications. Obstetric anal sphincter injuries, episiotomy rates, neonatal intensive care admissions, and low Apgar scores represented the most frequently documented metrics. Consequently, the lack of uniform reporting severely hinders evidence synthesis and clinical decision-making in obstetrics.

Comparison of Vacuum Extractor and Forceps Complications

Clinicians frequently weigh the benefits and risks of choosing vacuum extraction over forceps delivery. According to the review, crude unadjusted failure rates reached 9.4% for forceps and 6.7% for vacuum extractors. Additionally, maternal complications occurred more frequently following forceps applications. Specifically, postpartum hemorrhage affected 9.0% of forceps births compared to 3.9% of vacuum births. Obstetric anal sphincter injuries also demonstrated a higher prevalence in forceps deliveries at 18.2% versus 10.8% for vacuum deliveries. Furthermore, clinicians performed episiotomies in 69.4% of forceps cases and 62.0% of vacuum procedures. Regarding neonatal morbidity, forceps births resulted in higher neonatal intensive care admissions at 10.0% compared to 7.1% for vacuum extractors. Fortunately, severe neonatal complications remained uncommon for both instruments across all included trials.

Standardizing Metrics Through a Core Outcome Set

Heterogeneity in clinical trial reporting complicates the development of evidence-based obstetric guidelines. Moreover, existing studies rarely evaluate long-term maternal and pediatric outcomes after instrumental delivery. Therefore, researchers advocate for the urgent development of a standardized core outcome set. Establishing universal outcome definitions will enhance future meta-analyses and improve patient safety during labor. Consequently, clinicians will gain more reliable data to guide instrument selection during critical second-stage labor emergencies.

Frequently Asked Questions

Q1: Why is a core outcome set necessary for assisted vaginal birth research?

A core outcome set establishes standardized outcome definitions across trials. Consequently, it allows researchers to pool clinical data accurately and improves evidence-based decision-making in obstetric care.

Q2: How do complication rates compare between forceps and vacuum extractor deliveries?

Forceps deliveries demonstrate higher rates of postpartum hemorrhage, obstetric anal sphincter injury, and neonatal unit admissions compared to vacuum extractions. However, vacuum extraction carries a slightly lower procedural success rate.

Q3: Which maternal and neonatal outcomes are most commonly reported in clinical studies?

Studies most commonly report obstetric anal sphincter injuries, episiotomy performance, neonatal intensive care admissions, low Apgar scores, and postpartum hemorrhage.

References

1. Cabrera-Dandy M et al. Reported Outcomes for Assisted Vaginal Birth: A Systematic Review. Obstet Gynecol. 2026 Aug 27. doi: 10.1097/AOG.0000000000006414. PMID: 42659594.
2. Royal College of Obstetricians and Gynaecologists. Assisted Vaginal Birth. Green-top Guideline No. 26. London: RCOG; 2020.
3. American College of Obstetricians and Gynecologists. Operative Vaginal Birth. Practice Bulletin No. 219. Obstet Gynecol. 2020;135(4):e149-e159.