Obstetrics & Gynecology>>>>>Normal and Abnormal Labor and Delivery
Question 9#

A 32-year-old G3P2 at 39 weeks’ gestation presented to labor delivery with ruptured membranes. On examination, she was contracting regularly, and her cervix was 4-cm dilated. Her history was significant for two prior vaginal deliveries, with her largest child weighing 3800 g. Over the next 2 hours she progressed to 7-cm dilation. Four hours later, she remained 7-cm dilated. She had regular contractions and IUPC showed MVUs of 220. The estimated fetal weight by ultrasound was 3200 g.

Which of the following labor abnormalities best describes this patient?

A. Prolonged latent phase
B. Protracted active phase
C. Hypertonic dysfunction
D. Secondary arrest of dilation
E. Second stage arrest

Correct Answer is D


The labor portrayed is characteristic of a secondary arrest of dilation. The woman has entered the active phase of labor, as she previously progressed from 4 cm to 7 cm in less than 2 hours and then remains 7 cm over an additional 4 hours. New criteria for first stage arrest include 6 cm or more dilation with membrane rupture and no cervical change for 4 or more hours with adequate contractions, or 6 or more hours with inadequate contractions. New data suggests that historical criteria defining normal labor progress (cervical change of 1.2 cm/h for nulliparous women and 1.5 cm/h for multiparous women) are no longer valid.