Impact of the mode of delivery on maternal and neonatal outcome in spontaneous-onset breech labor at 32 +0 -36 +6 weeks of gestation: A retrospective cohort study.

OBJECTIVE: To compare neonatal and maternal outcomes in spontaneously onset preterm breech deliveries after trial of labor (BTOL) and intended cesarean section (BCS), and between BTOL and vertex control deliveries, in singleton fetuses at 32+0 -36+6  weeks of gestation.

STUDY DESIGN: Retrospective single center cohort study in a Finnish University Hospital including all spontaneous-onset preterm breech deliveries with 32 completed gestational weeks in 2003-2015. The study population comprised a total of 176 preterm breech and 103 vertex control deliveries, matched by gestational age and whether the mother had given birth vaginally before or not. Infants with severe malformations and antepartum fetal distress were excluded. Subgroup analyses were made in two cohorts according to gestational age. Main outcome measures were maternal and neonatal mortality and morbidity, low cord pH and Apgar score.

RESULTS: No mortality was observed, and severe morbidity was rare. No difference in incidence of low cord pH or five-minute Apgar score was observed between the groups. Apgar scores at the age of one minute were comparable in the breech groups but more often low in the BTOL group compared to the vertex control group. 16.5% of neonates in the BTOL group, 23.3% in the BCS group and 7.8% in the vertex group needed intensive care. In logistic regression analysis, lower gestational age and being small for gestational age were associated with the need for neonatal intensive care. Being allowed a trial of labor was not associated with the need for neonatal intensive care. Maternal morbidity was similar across the groups, but median blood loss was more pronounced in the BCS group compared to the BTOL group.

CONCLUSION: In breech deliveries at 32+0 -36+6 gestational weeks, trial of labor did not increase neonatal morbidity compared to intended cesarean delivery. Infants born after a trial of labor in breech presentation display low one-minute Apgar score and need intensive care more often compared to vertex controls.