“Reducing Emergency Caesareans and Improving the Primiparous Experience-The RECIPE Study”

Objective: The ability to predict the need for intrapartum Caesarean Delivery holds the potential to facilitate birth choices. The objective of the RECIPE study (Reducing Emergency Caesareans and Improving the Primiparous Experience) was to externally validate a Caesarean delivery risk prediction model. This model, produced by the Genesis study, identified 5 key predictors for nulliparous, intrapartum Caesarean delivery: maternal age, maternal height, maternal BMI, fetal head circumference and fetal abdominal circumference.

Study Design: We recruited from 2 large obstetric units for this prospective, observational study. Inclusion criteria were as follows: nulliparous women with a singleton, cephalic presentation fetus in the absence of IUGR, oligohydramnios, preeclampsia, pre-existing diabetes mellitus or an indication for planned CD. Participants attended for prenatal ultrasound and maternal data collection from 38+0 - 40+6 weeks’ gestation. Labour, delivery and postnatal outcomes were collected. The Genesis model was applied to the RECIPE cohort and a calibration curve was determined.

Results: 559 nulliparous participants were enrolled from May 2017 to April 2019, of whom 142 (25%) had a Caesarean delivery. Participants with a low predicted risk score (<10%) had a mean predicted rate of 8% (+/- Standard deviation of 2%) and a similarly low actual rate of Caesarean delivery (8%). Participants with a high predicted risk (>50%) had a mean predicted rate of 64% (+/- Standard deviation of 9%) and also had a high actual Caesarean delivery rate (62%). Our calibration curve and receiver operating characteristic curve demonstrated that this validation study showed similar discriminatory power for intrapartum Caesarean delivery to that described in the original Genesis study. The Area Under the Curve was 0.72, which reflects good predictive capacity of the risk prediction model. Of the study participants, 89% stated they would be happy to have known their risk score in advance of delivery, 98% were satisfied with their care during labour and, of those who had a Caesarean delivery, 100% were satisfied that the need for Caesarean delivery was adequately explained.

Conclusion: The accuracy of the intrapartum Caesarean delivery risk prediction model is supported by this validation study. Prelabour knowledge of a high prospect of achieving an uncomplicated vaginal birth reassures nulliparous women of their high probability of success and may help to stratify women into appropriate models of prenatal care.