Mode of delivery and mortality and morbidity for very preterm singleton infants in a breech position: A European cohort study

OBJECTIVE: Caesarean section (CS) may reduce mortality and morbidity for very preterm breech infants, but evidence is inconclusive. We evaluated neonatal outcomes for singleton breech infants by mode of delivery in a European cohort.

STUDY DESIGN: Data come from the EPICE population-based cohort of very preterm births in 19 regions in 11 European countries (7770 live births). The study population was singleton spontaneous-onset breech births at 24-31 weeks gestational age (GA) without antenatal medical complications requiring caesarean delivery (N = 572). Mixed-effects regression models adjusting for maternal and pregnancy covariates and propensity score matching was used to examine the effect of (1) CS and (2) a unit policy of systematic CS for breech presentation by GA. The primary outcome was a composite of in-hospital mortality, intraventricular haemorrhage grades III & IV or cystic periventricular leukomalacia. Secondary outcomes were each component separately, five minute Apgar score below seven and mortality within six hours of delivery.

RESULTS: 64.4% of infants were delivered by CS with a range across regions from 41% to 100%; these infants had higher GA and were more likely to be small for gestational age, receive antenatal steroids, and have mothers who were hospitalised for more than one day before delivery compared to those delivered vaginally. CS was associated with lower risks of all outcomes in mixed-effects adjusted models (odds ratio (OR) for the composite outcome: 0.50, 95% confidence interval (CI): 0.30-0.81), but not in propensity score matched models (OR: 0.72, 95% CI: 0.41; 1.29). A systematic CS policy was associated with lower mortality and morbidity in unadjusted, but not adjusted models (OR for composite outcome: 0.76, 95% CI: 0.44; 1.28). 35% of births 24-25 weeks were delivered by CS and protective effects were consistently stronger, but not statistically significant.

CONCLUSIONS: Point estimates indicated protective effects of caesarean delivery for very preterm breech infants in conventional statistical models. However, analyses using propensity scores and based on unit policies did not confirm statistically significant associations. Prospective large-scale studies are needed to establish best practice and could be implemented in European regions where vaginal delivery remains an option.