Trial and error - Outcome of breech presentation depending on birth mode and root cause analysis of severe adverse events

Abstract

Objectives: The debate about the safest birth mode for breech presentation at term remains unresolved. The comparison of a vaginal breech birth (VBB) with an elective caesarean section (CS) regarding fetal outcomes favors the CS. However, the question of whether attempting a VBB is associated with poorer fetal outcomes is examined in this study. Additionally, the study evaluates factors contributing to a successful VBB and illustrates possible errors in VBB management.

Study design: We performed a retrospective analysis of term breech births over 15 years in a Perinatal Center Level I regarding fetal, maternal, and obstetric outcomes by comparing successful with unsuccessful VBB attempt and all attempted VBB vs. CS including a multivariate analysis of predictors for a successful VBB. A root cause analysis of severe adverse events (SAE) was conducted to evaluate factors leading to poorer fetal outcomes in VBB.

Results: Of 863 breech cases, in 78 % a CS was performed and in 22 % a VBB was attempted, with 57 % succeeding. Comparing successful with unsuccessful VBB attempts, successful VBB showed significantly lower maternal blood loss (p < 0.001) but poorer umbilical arterial pH (UApH) (p < 0.001), while other fetal outcome parameters showed no significant differences. Predictive factors for a successful VBB attempt were a body mass index (BMI) below 30.0 kg/m² (p = 0.010) and multiparity (p = 0.003). Comparing all attempted VBB to CS, maternal blood loss was significantly higher in CS (p < 0.001), while fetal outcomes were significantly worse in VBB attempts, included poorer Apgar scores (p < 0.001), poorer UApH values (p < 0.001), higher transfer rate to the Neonatal Intensive Care Unit (NICU) (p < 0.001) and higher rate of respiratory support in the first 24 h (p = 0.003).

Conclusion: The failed attempt of VBB indicates significantly worse UApH without lower Apgar scores or higher transfer rate to the NICU. The likelihood of a successful VBB is 9% lower with obesity and 2.5 times higher in multiparous women. Attempting a VBB should include detailed pre-labor counseling, regarding predictive success factors, an experienced team, and consistent management during birth.

Keywords: Adverse events; Birth mode; Breech presentation; Fetal outcome; Maternal outcome; Vaginal breech birth.