A 23-year-old primigravida at 38 weeks gestation comes to labor and delivery for spontaneous rupture of membranes and painful contractions. The patient has had an uncomplicated prenatal course and a negative group B Streptococcus culture last week. Leopold maneuvers show an estimated fetal weight of 3.6 kg (8 lb). Cervical examination shows the cervix to be 8 cm dilated and 90% effaced with the fetal vertex at 0 station. The patient is admitted and epidural analgesia is administered. She reports increasing rectal pressure; repeat cervical examination is unchanged. An intrauterine pressure catheter is placed and shows contractions every 2-3 minutes, and the sum of contraction strength is 240 Montevideo units over 10 minutes. This contraction pattern continues, and 4 hours later the cervix remains unchanged. Fetal heart rate tracing is category 1. Which of the following is the best next step in management of this patient?

Question

A 23-year-old primigravida at 38 weeks gestation comes to labor and delivery for spontaneous rupture of membranes and painful contractions.  The patient has had an uncomplicated prenatal course and a negative group B Streptococcus culture last week.  Leopold maneuvers show an estimated fetal weight of 3.6 kg (8 lb).  Cervical examination shows the cervix to be 8 cm dilated and 90% effaced with the fetal vertex at 0 station.  The patient is admitted and epidural analgesia is administered.  She reports increasing rectal pressure; repeat cervical examination is unchanged.  An intrauterine pressure catheter is placed and shows contractions every 2-3 minutes, and the sum of contraction strength is 240 Montevideo units over 10 minutes.  This contraction pattern continues, and 4 hours later the cervix remains unchanged.  Fetal heart rate tracing is category 1.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_da43_b51f_bc81_2d858a6d582b_MD0003_00 The first stage of labor begins with the onset of regular contractions and ends when the cervix is 10 cm dilated. It consists of a latent phase involving gradual cervical dilation and an active phase with rapid dilation. The transition between the latent and active phase occurs at 6 cm dilation. The active phase of labor (6-10 cm cervical dilation) has an expected, predictable rate of cervical dilation of ≥1 cm every 2 hours. This patient has active phase arrest, defined as no cervical change for ≥4 hours despite adequate contractions (≥200 Montevideo units in a 10-minute interval) or no cervical change for ≥6 hours with inadequate contractions. Causes include uterine (eg, inadequate contractions), fetal (eg, malposition, macrosomia), or pelvic (eg, deformity or fracture) etiologies. ≥200 Montevideo units The best next step in management of active phase arrest is cesarean delivery because no further cervical dilation is expected and delaying delivery increases maternal-fetal morbidity (eg, intraamniotic infection, postpartum hemorrhage) (Choice E). (Choice A) Amnioinfusion is performed using an intrauterine pressure catheter and is indicated for fetal heart rate tracing abnormalities (ie, variable decelerations). It is not used for labor augmentation because it does not affect cervical dilation. (Choice C) Oxytocin augments labor by increasing contraction frequency and strength. Oxytocin is used for patients who meet criteria for labor protraction (ie, cervical dilation rate <1 cm/2 hr) but not for those who meet criteria for labor arrest. (Choice D) An operative vaginal delivery (eg, vacuum-assisted vaginal delivery) is performed during the second stage of labor (10 cm dilation until fetal delivery) to expedite delivery for category III tracings or maternal exhaustion. This patient is 8 cm dilated. Educational objective: Active phase arrest occurs at a cervical dilation of ≥6 cm and is defined as no cervical change for ≥4 hours with adequate contractions or ≥6 hours with inadequate contractions. Active phase arrest is managed by cesarean delivery. References: Preventing the first cesarean delivery: summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, and American College of Obstetricians and Gynecologists workshop. (http://www.ncbi.nlm.nih.gov/pubmed/23090537) Contemporary patterns of spontaneous labor with normal neonatal outcomes. (http://www.ncbi.nlm.nih.gov/pubmed/21099592)

A 23-Year-Old Primigravida at 38 Weeks Gestation Comes to Labor