Validation of Ultrasound "Angle of Progression" Measurement to Decrease the Cesarean Rate (DELIVERY)

Validation of Ultrasound "Angle of Progression" Measurement to Decrease the Cesarean Rate : a Randomized Comparative Multicenter Prospective Study.

Ultrasound during labor and measurement of Angle of progression showed extensive prospective and retrospective publications since 2010. The investigators performed between 2013 and 2016 the only one multicenter, randomized controlled Trial comparing digital exam to angle of progression after a prolonged 2-hour second stage of labor with uncertain fetal head. The investigators consider a cut off of 120° to accepted vaginal birth among cephalic occiput anterior position This randomised PILOT study showed that measurement of Angle of progression in addition to digital exam reduced caesarean delivery from 41% to12% ( n= 33, p=0,06). doi: 10.1016/j.ajog.2022.04.018. The objective of this new study is therefore to validate the results of this PILOT study in a more powerful multicenter randomized trial (DELIVERY).

The mode of delivery will be determined by clinical examens (digital examination) and ultrasound measurement of the AOP : vaginal delivery is encouraged if AOP measurement is >120° cesarean delivery is encouraged if AOP measurement is <= 120°

The angle of progression (AOP) defined as the angle between the pubic bone axis and the leading part of the fetal head

Demonstrate that the angle of progression measurement would change by 20% the cesarean rate after a prolonged second stage of labor (2 hours).

A complicated deliveries is defined by the occurrence of at least one of the following events : Failed instrumental extraction Sequential use of a second instrument, Difficult instrumental extraction defined as : vacuum detachment requires the use of a second instrument, extraction time > 10 minutes, operator's impression of the difficulty of extraction, Shoulder dystocia by obstetric maneuver

Severe maternal morbidity is defined by the occurrence of at least one of the following events: postpartum hemorrhage requiring hysterectomy, embolization, conservative surgical treatment or blood transfusion, third or fourth degree perineal tears vaginal thrombus, cervical tear, surgical wounds sepsis, amniotic embolism, cardiac complication or renal failure.

Severe neonatal morbidity, in each group, defined by the occurrence of at least one event below: severe biological signs moderate or absent biological signs but associated with perinatal events seizure severe neonatal trauma Fetal death or neonatal death.

Inclusion Criteria: Nulliparous or multiparous women with no history of vaginal delivery, > or = 37 weeks amenorrhoea Cephalic presentation in anterior position (occipito-pubic position, left anterior occipito-iliac and right anterior occipito-iliac ) confirmed by ultrasound uncertain fetal head engagement on digital examination or midline fetal presentation in prolonged second stage of labor (at least 2 hours), Exclusion Criteria: Multiparous women who were previous vaginal deliveries, Presentation other than cephalic, Twin pregnancies, Posterior or transverse position Transperineal ultrasound for head-perineum distance measurement Fetal heart rate abnormalities requiring rapid delivery, Contraindication to vaginal delivery whether maternal or fetal