Outcome measures
The primary outcome was mode of birth (planned caesarean section vs. intended VBAC) among women with one previous caesarean section. Secondary outcomes were VBAC success rates of women with one previous caesarean section and the rate of adverse perinatal outcomes (Apgar score <7 after five minutes, asphyxia, NICU admission of at least 24 hours and perinatal death up to 28 days postpartum) among women with one previous caesarean section intending a VBAC compared to women who underwent a planned caesarean section.
Elaborate definitions of intended VBAC (i.e., trial of labour after caesarean, TOLAC), VBAC success rate, NICU admission of at least 24 hours, asphyxia, and perinatal mortality can be found in Appendix S1. Maternal and perinatal characteristics of women are described using international definitions and cut-off values and can also be found in Appendix S1.