The Impact of Maternal BMI on the Efficacy and Safety of Oral Misoprostol for Labor Induction

<b>Background</b>: Maternal obesity may influence the efficacy and course of induction of labor (IoL). Misoprostol, a prostaglandin E1 analogue, is widely used for cervical ripening, but evidence regarding its effectiveness in obese women remains limited. This study aimed to evaluate the efficacy and safety of oral misoprostol for IoL across different body mass index (BMI) categories. <b>Methods</b>: This prospective study was conducted at a tertiary center. Term singleton pregnancies with medical indications for IoL and an unfavorable cervix (Bishop score < 6) received oral misoprostol 50 μg every 4 h to a maximum of 200 μg. Primary outcomes were vaginal delivery (VD) rates. Secondary outcomes included cesarean section (CS) rate, oxytocin use, labor duration, analgesia, adverse events, and neonatal outcomes. <b>Results</b>: Among 291 participants (43.0% overweight; 40.2% obese), the Bishop score increased from 2.3 to 6.2 (<i>p</i> < 0.0001). VD occurred in 77.3%, and CS in 22.7%. Most women delivered within 48 h (96.6%). Higher BMI correlated with longer time to contractions, pain onset, and delivery, as well as with more misoprostol doses. Neonatal outcomes were uniformly favorable, with median Apgar scores of 10 at 1, 5, and 10 min, and mean umbilical pH values ranging from 7.2 to 7.3. Adverse events were infrequent, with tachysystole observed in 1.7% of cases. <b>Conclusions</b>: Oral misoprostol is an effective and safe IoL method across BMI categories, achieving high vaginal delivery rates and favorable neonatal outcomes. Obesity modestly prolongs induction and increases dose requirements, supporting individualized dosing and close monitoring.