Breech delivery at term: a critical review of the literature

To determine whether planned vaginal or elective cesarean delivery is better for singleton term breech infants.

Articles that included singleton term pregnancies with breech presentation published in English between 1966 and September 1992 were searched through the Index Medicus, Oxford Database of Perinatal Trials, and MEDLINE.

We reviewed 24 studies that presented results according to the intended mode of delivery in terms of the following adverse outcomes: perinatal mortality, low 5-minute Apgar score, traumatic neonatal morbidity, overall short-term neonatal morbidity, long-term infant morbidity, and maternal morbidity and mortality.

The effect of planned vaginal delivery, compared with planned cesarean delivery, for each adverse outcome was determined by calculating a typical odds ratio. Perinatal mortality was higher for the planned vaginal delivery groups than for the elective cesarean groups, with a typical odds ratio of 3.86 (95% confidence interval [CI] 2.22-6.69). Neonatal morbidity due to trauma was also higher for the planned vaginal delivery groups, with a typical odds ratio of 3.96 (95% CI 2.76-5.67).

The results suggest that planned vaginal delivery may be associated with higher perinatal mortality and morbidity rates than planned cesarean delivery. Because of selection bias in the majority of studies, differences in outcomes may be due to factors other than the planned method of delivery. An appropriately sized, randomized controlled trial is needed to answer this question definitively.