Mode of delivery and adverse short- and long-term outcomes in vertex-presenting very preterm born infants: a European population-based prospective cohort study.

Objectives: To compare mortality, morbidity and neurodevelopment by mode of delivery (MOD) for very preterm births with low prelabour risk of caesarean section (CS).

Methods: The study was a population-based prospective cohort study in 19 regions in 11 European countries. Multivariable mixed effects models and weighted propensity score models were used to estimate adjusted odds ratios (aOR) by observed MOD and the unit's policy regarding MOD. Population: Singleton vertex-presenting live births at 24 + 0 to 31 + 6 weeks of gestation without serious congenital anomalies, preeclampsia, HELLP or eclampsia, antenatal detection of growth restriction and prelabour CS for fetal or maternal indications.

Results: Main outcome measures: A composite of in-hospital mortality and intraventricular haemorrhage (grade III/IV) or periventricular leukomalacia. Secondary outcomes were components of the primary outcome, 5 min Apgar score <7 and moderate to severe neurodevelopmental impairment at two years of corrected age. The rate of CS was 29.6% but varied greatly between countries (8.0-52.6%). MOD was not associated with the primary outcome (aOR for CS 0.99; 95% confidence interval [CI] 0.65-1.50) when comparing units with a systematic policy of CS or no policy of MOD to units with a policy of vaginal delivery (aOR 0.88; 95% CI 0.59-1.32). No association was observed for two-year neurodevelopment impairment for CS (aOR 1.15; 95% CI 0.66-2.01) or unit policies (aOR 1.04; 95% CI 0.63-1.70).

Conclusions: Among singleton vertex-presenting live births without medical complications requiring a CS at 24 + 0 to 31 + 6 weeks of gestation, CS was not associated with improved neonatal or long-term outcomes.