Background: The aim of this study was to compare the effect of fetal presentation and mode of delivery on infant outcome in a nation-wide study.
Methods: In a retrospective observational cohort study, we compared, with the help of Finnish Medical Birth Register and other nation-wide registers, the short-term and long-term outcome of infants born by breech vaginal (n = 1270) or by vertex vaginal delivery (n = 128,683) or through planned cesarean section (CS) in breech (n = 1640) or vertex (n = 4997); the pregnancies were otherwise entirely normal.
Results: One perinatal death occurred in the breech vaginal group and 23 deaths in the vertex vaginal group (p = 0.112), but none in either CS group. Breech vaginal delivery was associated with increased risk of Apgar scores 6 or less at age 1 min (OR 7.65, CI 6.41-9.12) and at age 5 min (OR 6.42, CI 4.36-9.45) as compared with vertex vaginal delivery. These odd ratios were also elevated (OR 4.59, CI 3.48-7.08 and OR 7.58, CI 3.09-18.66, respectively) when compared with breech planned CS. Yet the risk for birth trauma of infants in the breech vaginal group was smaller (OR 0.70, CI 0.51-0.96) than that in the vertex vaginal group but this risk was smallest in the planned CS groups. A number of other neonatal complications occurred equally commonly in each group. Breech infants born vaginally needed fewer admissions (OR 0.58, 0.47-0.72) to out-patient departments and the cumulative incidence of long-term morbidity in the breech vaginal group was smaller (OR 0.47, CI 0.28-0.80) to the age of 7 years than that in the breech planned CS. The maturity for starting school and school performance during the first two school years showed no dependence on mode of delivery.
Conclusion: Apart from Apgar suppression, elective vaginal delivery of a full-term breech fetus in highly selected pregnancies does not cause additional neonatal hazards as compared with full-term vertex deliveries. The immediate outcome was best for breech or vertex infants born through elective CSs.