Les présentations postérieures augmentent-elles le risque de déchirures périnéales sévères ?

Abstract

Objective To assess the risk of severe perineal lacerations (III and IV degrees) during vaginal deliveries in occiput posterior position. Patients and methods We conducted a retrospective cohort study of 9097 vaginal deliveries in a teaching hospital's maternity between January 1st 2005 and December 31st 2008. Risk factors associated with tears of the 3rd or 4th degree were studied by a multivariate logistic regression. Results Severe perineal lacerations occurred in 1.69% of cases ( n = 152) and did not significantly vary between 2005 and 2008. Parity was a protective factor (OR 0.42; P < 0.001; IC 95% 0.29–0.60) whereas instrumental extraction was associated with an increased risk: vacuum (OR 3.95; P < 0.001, IC 95% 2.23–7.00) and forceps (OR 3.55; P < 0.001, IC 95% 2.33–5.42). macrosomia. Risks were also increased in fetal macrosomia and episiotomy did not protect the mother (respectively OR 1.41 P < 0.001, IC 95% 1.19–1.68 and OR 1.73; P < 0.001, IC 95% 1.16–2.57). Persistent occiput posterior position was not significantly associated with an anal sphincter injury (OR = 1.70 P = 0.059; IC 95% 0.98–2.94). Discussion and conclusion In our series, occiput posterior position did not significantly impact the risk of severe perineal laceration. A manual rotation of the fetal head should be performed in case of associated risk factors.