[Factors predicting unsuccessful labor induction with dinoprostone in post-term pregnancy with unfavorable cervix]. / Facteurs prédictifs d'échec d'entrée en travail par dinoprostone en cas de grossesse prolongée et de conditions locales défavorables.

OBJECTIVE: To identify predictive factors for unsuccessful induction of labor within 24hours after dinoprostone insertion in post-term pregnancy with unfavorable cervix. MATERIAL AND METHODS: We retrospectively reviewed 325 singleton pregnancies with a diagnosis of post-term pregnancy and unfavorable cervix (Bishop score<6) during the period January 2012-Decembre 2012. Patients were classified into 2 groups: successful labor, defined as cervical ripening, within 24hours after dinoprostone insertion (Group R; n=248; 76.3 %) or failure group (Group E; n=77; 23.7 %). Antepartum and perpartum characteristics of women were compared. RESULTS: Nulliparity (74.0 versus 56.0 %; OR=2.23; 95 % CI: 1.27-4.00; P=0.005), gestational age ≤41 SA+4 (53.2 versus 33.9 %; OR=2.22; 95 % CI: 1.32-3.74; P=0.003) and history of dilatation and curettage (27.3 versus 10.5 %; OR=3.19; 95 % CI: 1.66-6.11; P=0.0005) were significantly associated with unsuccessful induction of labor. Bishop score was significantly higher in Group R (3.6 versus 1.9; P=0.001). Also, consistency (74.0 versus 44.4 %; OR=3.57; 95 % CI: 2.04-6.40; P<10(-5)) and absence of dilatation of the cervix (59.7 versus 23.0 %; OR=4.97; 95 % CI: 2.89-8.56; P<10(-6)) were identified as significant predictive factors for unsuccessful induction of labor. CONCLUSION: Nulliparity, gestational age ≤41 SA+4, history of dilatation and curettage and Bishop score, in particular consistency and dilatation, are correlated with failure of cervical ripening in post-term pregnancy with unfavorable cervix.