Neonatal outcome in vaginal breech labor at 32 + 0—36 + 0 weeks of gestation: a nationwide, population-based record linkage study

BACKGROUND: In many countries, vaginal breech labor at term is an option in selected cases. However, the safety of vaginal breech labor in preterm is still unclear. Therefore our study aimed to evaluate the safety of vaginal breech labor in late preterm deliveries. DESIGN: A retrospective register-based study. SETTING: Maternity hospitals in Finland, 2004–2017. PARTICIPANTS: The study population included 762 preterm breech deliveries at 32 + 0—36 + 6 gestational weeks according to the mode of delivery, 535 (70.2%) of them were born vaginally in breech presentation, and 227 (29.8%) were delivered by non-urgent cesarean section. METHODS: The study compared short-term neonatal adverse outcomes of singleton vaginal breech deliveries with non-urgent cesarean deliveries at 32 + 0 to 36 + 6 weeks of gestation. An odd ratio with 95% confidence intervals was calculated to estimate the relative risk of adverse outcomes. OUTCOME MEASURES: Neonatal death, an arterial umbilical pH below seven, a five-minute Apgar score below four and seven, admission to neonatal intensive care unit, neonatal intubation, neonatal antibiotic therapy, neonatal birth trauma, respiratory distress syndrome, neonatal convulsions, cerebral ischemia, hypoxic-ischemic encephalopathy, congenital hypotonia, and a composite of severe adverse outcomes. RESULTS: A five-minute Apgar scores below seven were increased in vaginal breech labor at 32 + 0 to 36 + 6 weeks of gestation compared to non-urgent cesarean sections (aOR 2.48, 95% CI 1.08–5.59). Neonatal antibiotic therapy, the admission to neonatal intensive care unit, and neonatal respiratory distress syndrome were decreased after vaginal breech labor compared to the outcomes of non-urgent cesarean section (neonatal antibiotic therapy aOR 0.60, 95% CI 0.40–0.89; neonatal NICU admission aOR 0.47, 95% CI 0.33–0.68; respiratory distress syndrome aOR 0.30, 95% CI 0.19–0.48). CONCLUSION: Vaginal breech labor at 32 + 0—36 + 6 gestational weeks does not increase severe neonatal short-term morbidity or mortality compared to cesarean section.