[Obstetric and perinatal outcomes of a disreputable presentation: the nonfrank breech]

A nonfrank breech is generally believed to be associated with abnormal labor and risk of cord prolapse. Owing to these risks, many authors consider such a presentation as a positive indication for cesarean section. The purpose of this study was to estimate the delivery characteristics of nonfrank breech with a gestational age over 37 weeks and particularities of this presentation.

This retrospective study included all deliveries with a nonfrank breech presentation and a gestational age over 37 weeks over a sixteen years period in our maternity ward. A descriptive analysis of maternal, fetal and obstetrical elements was carried out.

198 deliveries were indexed with 54% vaginal birth, regularly observed throughout the study period. Thirty percent delivered by prelabor planned cesarean section and 16% by cesarean section during labor. When a vaginal birth trial was allowed, at last 77.4% delivered by this route. Average labor time in the vaginal birth group was only 4.5 hours. Eleven cord prolapses were found (5.6%) of which more than half delivered by vaginal birth without fetal complications. Perinatal outcomes were satisfactory for the whole population, without differences between cesarean section and vaginal birth.

Cord prolapse is a risk of nonfrank breech presentation but abnormal labor is not more frequent than with frank breech presentations if labor is managed rigorously. More than 75% patients of the vaginal birth trial group delivered by vaginal birth with perinatal outcomes as good as the cesarean section group. Unlike traditional reports, in our study a nonfrank breech was not an unfavorable factor for vaginal birth after strict selection of vaginal birth trial candidates.