[Breech Presentation: CNGOF Guidelines for Clinical Practice - Epidemiology, Risk Factors and Complications]

Objectives: To study the frequency, the risk factors and the mode of delivery of breech presentation. To analyze the perinatal morbidity and mortality associated with breech presentation in comparison to cephalic presentation from all mode of delivery.

Methods: MedLine and Cochrane Library databases search in French and English and review of the main foreign guidelines between 1980 and 2019.

Results: Three modes of breech presentation exist according to fetal lower limbs position: frank in 2/3 of cases, complete in 1/3 of cases or, more rarely, incomplete (LE3). About 5% of women gave birth in breech presentation in France (LE3). As the frequency of breech presentation decreases with increasing gestational age, this incidence is lower after 37 WG and represents only 3% of term deliveries (LE3). Congenital uterine malformation (LE3) and fibroma (LE3), prematurity (LE3), oligoamnios (LE3), some fetal congenital malformations (LE3) and low birthweight for gestational age (LE3) are the main risk factors with breech presentation. In France, one-third of women with a term fetus in breech presentation attempt a vaginal delivery (LE3), which is successful in 70% of cases (LE3). Neonatal outcome is not associated with type of breech presentation (frank or complete) in case of vaginal delivery attempt after 37 WG (LE3). Overall, perinatal morbidity and mortality after 37 WG of breech presentation appear to be greater than in cephalic presentation from all mode of delivery (LE3). The risk of traumatic injury in breech delivery is estimated under 1% (LE3). The most common injuries are collarbone fractures, hematomas or contusions, and brachial plexus injury (LE3). Breech presentation is associated with an increased risk of hip dysplasia (LE3) and cesarean delivery does not seem to be a protective factor (LE3). Breech presentation does not appear to be associated with an increased risk of cerebral palsy compared to cephalic presentation after exclusion of fetuses with congenital malformations (LE3).

Conclusion: Worldwide, mode of delivery of breech presentation has undergone profound changes since the publication of the TBT (Term Breech Trial). There are intrinsic factors associated with breech presentation, which should not be overlooked when interpreting the increased perinatal morbidity and mortality observed in case of breech presentation.