A 22-year-old woman, gravida 1 para 0, at 37 weeks gestation comes to labor and delivery for intermittent leakage of fluid for the past 6 hours. The patient has had some intermittent green-tinged fluid and is now having regular, painful contractions every 3-4 minutes. She has had no vaginal bleeding, and fetal movement is normal. The patient has had an uncomplicated pregnancy, and her group B Streptococcus culture was negative a week ago. She has no chronic medical conditions and has had no surgeries. Temperature is 37.2 C (99 F), blood pressure is 90/68 mm Hg, and pulse is 98/min. Fetal heart rate tracing is shown in the exhibit. Sterile speculum examination confirms rupture of membranes with meconium-stained amniotic fluid. On digital cervical examination, the cervix is 6 cm dilated, 90% effaced, and the fetal vertex is at +1 station. The fetal heart rate pattern is unchanged with maternal repositioning and oxygen administration. Which of the following is the best next step in management of this patient?

Question

A 22-year-old woman, gravida 1 para 0, at 37 weeks gestation comes to labor and delivery for intermittent leakage of fluid for the past 6 hours.  The patient has had some intermittent green-tinged fluid and is now having regular, painful contractions every 3-4 minutes.  She has had no vaginal bleeding, and fetal movement is normal.  The patient has had an uncomplicated pregnancy, and her group B Streptococcus culture was negative a week ago.  She has no chronic medical conditions and has had no surgeries.  Temperature is 37.2 C (99 F), blood pressure is 90/68 mm Hg, and pulse is 98/min.  Fetal heart rate tracing is shown in the exhibit.  Sterile speculum examination confirms rupture of membranes with meconium-stained amniotic fluid.  On digital cervical examination, the cervix is 6 cm dilated, 90% effaced, and the fetal vertex is at +1 station.  The fetal heart rate pattern is unchanged with maternal repositioning and oxygen administration.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_da30_2df6_bc81_c14992072ef1_MD0003_00 Intrapartum electronic fetal heart rate (FHR) monitoring is used to assess fetal brain oxygenation status because a well-oxygenated brain provides autonomic control of the heart. FHR patterns are divided into 3 categories based on risk of fetal hypoxia. A category I FHR tracing has a baseline heart rate of 110-160/min with moderate variability (average amplitude 6-25/min) and no decelerations; this pattern has a low risk for fetal hypoxia. Variations from this pattern are suggestive of fetal hypoxia, which can lead to acidemia and possible demise. This patient's FHR tracing has absent variability plus recurrent late decelerations (ie, late decelerations with ?50% of contractions)-diagnostic of a category III FHR tracing. Patients with a category III tracing have an increased risk of severe fetal hypoxia (and subsequent hypoxic brain injury or demise)-as seen in this patient with late decelerations, which are likely due to uteroplacental insufficiency. FHR tracing The initial management of category III tracings is with maternal repositioning and other intrauterine resuscitative interventions (eg, oxygen administration, intravenous fluids, discontinuing uterotonics) that improve uteroplacental blood flow and fetal oxygenation. Patients remote from delivery (not completely [10 cm] dilated) who do not improve with initial resuscitative measures require an immediate cesarean delivery. (Choice A) Amnioinfusion is indicated for category III tracings with recurrent variable decelerations because amnioinfusion may help relieve the umbilical cord compression that causes these decelerations. It is not indicated in the management of recurrent late decelerations. variable decelerations (Choice B) A biophysical profile is not used during the intrapartum period because it does not change management and may delay more appropriate interventions. (Choice D) Oxytocin (a uterotonic agent) augmentation increases the strength and frequency of contractions, thereby worsening uteroplacental blood flow and further compromising fetal oxygenation. Uterotonic agents are discontinued in management of category III tracings. (Choice E) An operative vaginal delivery (eg, vacuum-assisted vaginal delivery) is a management option for patients with category III FHR tracings and complete (10 cm) cervical dilation, not seen in this patient. Educational objective: Patients with category III fetal heart rate tracings are at increased risk of fetal hypoxia and subsequent fetal acidemia, hypoxic brain injury, and demise. Initial management is with intrauterine resuscitative interventions; those who do not improve with initial management and are remote from delivery require immediate cesarean delivery. References: An evaluation of fetal heart rate characteristics associated with neonatal encephalopathy: a case-control study. (http://www.ncbi.nlm.nih.gov/pubmed/29575562) The 2008 National Institute of Child Health and Human Development workshop report on electronic fetal monitoring: update on definitions, interpretation, and research guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/18757666)

A 22-Year-Old Woman, Gravida 1 Para 0, at 37 Weeks