Planned Mode of Delivery After Caesarean: a Comparative Prospective National Population-based Cohort Study

Primary and secondary objectives :

The primary objective is to evaluate the non-inferiority of TOLAC compared to ERCD on the perinatal morbidity-mortality rate. The secondary objectives are to compare between the TOLAC and ECRD groups: the maternal morbidity-mortality rate, care trajectories of women and child one year after delivery, the uterine rupture rate, pain experienced during delivery, the breastfeeding rates at the time of hospital discharge and at 6-weeks postpartum, the satisfaction, the quality of life, and the bonding of women at 6-weeks postpartum, the risk of postnatal depression, and the post-traumatic stress disorder at 6-weeks postpartum, the medical resource costs and perform a cost-effectiveness analysis or a cost-minimization analysis depending on the result on the primary endpoint, the risk perception of women and of the obstetrician about the course of delivery: at the time of the shared decision-making process with the obstetrician of their planned mode of delivery, two days after delivery, and at 6-weeks postpartum (ancillary study CICAMODA Risk), and the risk of urinary incontinence at 12 months postpartum (ancillary study CICAMODA PP).

Methods :

• Design : the investigators plan a national multicentre prospective observational cohort study.
• General procedure : after admission of the women in the labour ward and within the 72 hours after birth, obstetricians will inform women about the study and determine whether or not they object to participate, in accordance with French law. The investigators will collect data about characteristics of the women, the previous caesarean delivery, the planned mode of delivery, the pregnancy, the course of labour, and postpartum data.
• Schedule : the investigators plan a 12-month inclusion period to obtain a complete view of French practices in planned mode of delivery after one previous caesarean delivery thanks to this observational study. The duration of the follow-up period will be 12-months for each included woman.
• Sample size : thanks to data of 2016 National Perinatal Survey, the investigators assume that TOLAC will be planned in 68.9% of French women with one previous caesarean and ERCD in the remaining 31.1%.

From an analysis of the literature, the investigators estimate that the perinatal morbidity-mortality rate is 0.9% in the ERCD group. The noninferiority boundary based on clinical evidence and an expert committee has validated an estimated rate of perinatal morbidity-mortality of 1.4% in the TOLAC group. According to these assumptions and with a power of 80% and a one-sided alpha risk of 2.5%, the number of women to be included is 4343 in the ERCD group and 9669 in the TOLAC group, i.e. a total of 14,012 women. With anticipation that 5% of women will provide incomplete data to define the primary outcome, 14750 women will be needed.