Prediction of adverse outcome associated with vaginal misoprostol for labor induction M. Mutlu Meydanli * , Eray Caliskan, Ali Haberal SSK Maternity and Women’s Health Teaching Hospital, Ankara, Turkey Received 10 January 2002; received in revised form 20 November 2002; accepted 8 January 2003 Abstract Objective: To identify predictors of adverse outcome in pregnant women at term receiving 50 mg of intravaginal misoprostol for labor induction. Study design: A prospective observational study was conducted of 720 pregnant women at term with an unfavorable cervix and a medical or obstetric indication for labor induction. All patients received 50 mg of intravaginal misoprostol every 4 h up to three doses. The primary outcome measure was ‘‘adverse outcome’’defined as: neonatal death, fetal acidemia and emergent cesarean delivery performed for non-reassuring fetal heart rate tracings. A stepwise logistic regression analysis was used to identify predictors of adverse outcome. Results: Tachysystole (frequent uterine contractions) (odds ratio (OR), 3.7; 95% confidence interval (CI), 1.2–10.8) and fetal tachycardia (OR, 4.8; 95% CI, 1.4–16.2) were determined as significant predictors of adverse outcome. The specificity of the model was 94.2%, whereas the sensitivity was 20.4%. Conclusion: In the absence of tachysystole and fetal tachycardia, an uneventful delivery might be expected for women receiving 50 mg of intravaginal misoprostol. # 2003 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Misoprostol; Labor induction; Adverse outcome 1. Introduction The principal goal of cervical ripening and labor induction is to achieve safe vaginal delivery [1]. Several indications necessitate induction of labor in patients with unfavorable cervices [2]. Failed induction of labor is most likely when the cervix is unfavorable and, in this circum- stance, vaginal prostaglandin preparations have proved to be beneficial [3]. Recently, the prostaglandin E 1 (PGE 1 ) analogue, miso- prostol has received increased attention as a highly effective agent for cervical ripening and labor induction in pregnant women at term. Misoprostol is a methyl ester of PGE 1 additionally methylated at C-16. It has been marketed as a gastric cytoprotective agent for the prevention and treat- ment of peptic ulcer disease caused by prostaglandin synthe- tase inhibitors. In addition, misoprostol acts as an effective myometrial stimulant of the pregnant uterus, selectively binding to EP-2/EP-3 prostanoid receptors [4]. The ability of misoprostol to stimulate uterine contrac- tions has been used for clinical purposes. More than 40 randomized trials have been published underscoring clinical recognition of the convenience that labor induction with misoprostol offers [5]. However, the debate about the safety of misoprostol used for labor induction persists because of its potential risk of inducing excessive uterine activity [3]. Although misoprostol has not been approved by the Food and Drug Administration for cervical ripening and labor induction, this medication has the advantage of being inex- pensive, easy to store and stable at room temperature. In this study, we have focused on the safety of 50 mg of intravaginal misoprostol. The purpose of this paper was to identify predictors of adverse outcome such as neonatal death, emergent cesarean delivery performed for non-reas- suring fetal heart rate (FHR) tracings, and fetal acidemia (pH  7:15 in an umbilical cord arterial blood sample) in pregnant women at term receiving 50 mg of intravaginal misoprostol for labor induction. 2. Materials and methods This was a prospective observational study describing the incidence of adverse outcome in a population of women European Journal of Obstetrics & Gynecology and Reproductive Biology 110 (2003) 143–148 * Corresponding author. Present address: Turgut Ozal Medical Center, Department of Obstetrics and Gynecology, School of Medicine, Inonu University, 44069 Malatya, Turkey. Tel.: þ90-422-341-0660/-4707; fax: þ90-422-341-0728. E-mail address: mmmeydanli@superonline.com (M. Mutlu Meydanli). 0301-2115/$ – see front matter # 2003 Elsevier Science Ireland Ltd. All rights reserved. doi:10.1016/S0301-2115(03)00105-2