A patient at 41 weeks undergoes induction of labor with dinoprostone (PGE2) pessary. After 12 hours, the cervix is 2 cm dilated, soft, and effaced 70%. Fetal CTG is normal. What is the appropriate next step?

• A Proceed immediately to cesarean section — failed induction after 12 hours
• B Proceed to amniotomy and oxytocin infusion once cervix is favorable for ARM ✓
• C Insert a second dinoprostone pessary and reassess in 24 hours
• D Insert Foley balloon catheter as mechanical adjunct alongside oxytocin

Explanation

A cervix that is 2 cm dilated, soft, and 70% effaced after prostaglandin priming is sufficiently favorable (modified Bishop score likely ≥6) for artificial rupture of membranes (ARM) followed by oxytocin augmentation. This is the natural progression of the induction protocol when prostaglandins have achieved cervical ripening. A second dinoprostone is only needed if cervical ripening is insufficient. Cesarean at this stage is premature with a favorable cervix and normal CTG. ACOG/RCOG protocols support proceeding to amniotomy when cervix is ≥2 cm dilated and favorable.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.