Mediolateral Episiotomy and Obstetric Anal Sphincter Injuries in Instrumental Delivery

Mediolateral Episiotomy and Prevention of Obstetric Anal Sphincter Injuries in Instrumental Delivery: a Prospective Population-based Propensity Score Study

Literature is contradictory about the impact of mediolateral episiotomy during operative vaginal delivery in obstetric anal sphincter injuries prevention explaining the absence of international guidelines. The investigators consider that a randomized trials does not appears feasible for both ethical and practical reason and so we suggest a large national observational study.

The investigators will include all nulliparous women that underwent an operative vaginal delivery within the 72h following the delivery at more than 34 weeks of amenorrhea. The investigators will collect data about the history of pregnancy, the course of labor, the mode of delivery, maternal immediate and one-year morbidity, neonatal immediate morbidity. The investigators expect a one-year study in 129 recruiting center with 15000 included women.

The primary objective is to assess the protective effect of mediolateral episiotomy against obstetric anal sphincter injury during instrumental delivery in nulliparous women according to the type of instrument used. The secondary endpoints are to investigate the effect of mediolateral episiotomy on one-year maternal morbidity, immediate maternal morbidity. The investigators also aim to develop a clinical score to assess the absolute risk of obstetric anal sphincter injury during instrumental delivery. Finally, the investigators will investigate the impact of fetal presentation ultrasound assessment immediately before instrumental delivery on the mode of delivery.

Inclusion Criteria:

• age of 18 years or older
• nulliparity and instrumental delivery of a singleton in cephalic presentation in the previous 72 hours including failure of vaginal instrumental delivery leading to cesarean section

Exclusion Criteria:

• expression of any opposition or objection to study participation
• previous delivery of a fetus at a gestational age greater than 20 weeks, regardless of the mode of delivery
• preterm birth before 34 weeks of amenorrhea
• fetal presentation other than cephalic
• multiple pregnancy
• in utero death
• inability to understand French
• under judicial protection
• without access to a numeric terminal with internet connexion