Ten minutes later, the fetal heart rate tracing appears as shown in the exhibit. Digital cervical examination is unchanged. Which of the following is the best next step in management of this patient?

Question

Ten minutes later, the fetal heart rate tracing appears as shown in the exhibit.  Digital cervical examination is unchanged.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_da2f_91b5_bc81_9f149d10aeba_MD0003_00 Umbilical cord compression impedes fetal-placental blood flow by occluding the umbilical blood vessels. Fetal tolerance of impeded fetal-placental blood flow (and subsequent hypoxemia and acidemia) correlates with the ratio of umbilical cord compressions to contractions. Intermittent umbilical cord compression, evidenced by variable decelerations with <50% of contractions, is typically well tolerated by the fetus (ie, no hypoxia) and does not require intervention. In contrast, umbilical cord compression with ?50% of contractions (as evidenced by recurrent variable decelerations) can result in a lack of fetal-placental blood flow, which the fetus cannot tolerate, and causes hypoxemia and acidosis. This patient's fetal heart rate (FHR) tracing now shows a normal baseline, moderate variability (average amplitude of 6-25/min), and recurrent variable decelerations. First-line management of recurrent variable decelerations is intrauterine resuscitation with maternal repositioning (eg, left lateral, all-fours), which may reduce cord compression and improve fetal-placental blood flow. If the variable decelerations do not improve, an amnioinfusion (instillation of saline into the intrauterine cavity) can be administered. An amnioinfusion artificially creates more amniotic fluid, which can reduce umbilical cord compression and decrease variable decelerations on FHR monitoring. (Choice A) A cesarean delivery is indicated in patients with absent variability and recurrent variable decelerations (ie, category III FHR tracing). This patient's FHR tracing has moderate variability; therefore, intrauterine resuscitation should be attempted first. If this patient's FHR tracing becomes a category III tracing, cesarean delivery would be indicated. category III FHR tracing (Choice B) Fetal scalp stimulation is performed to evaluate fetal acidosis in patients who have no accelerations on FHR monitoring. Fetal scalp stimulation is not performed in patients with decelerations, as it can exacerbate a parasympathetic response, resulting in a prolonged deceleration or fetal bradycardia. (Choice C) An operative vaginal delivery (eg, forceps, vacuum) is indicated to expedite deliveries in patients with complete (10 cm) cervical dilation. (Choice E) Oxytocin augmentation increases contraction strength and frequency, thereby increasing umbilical cord compression and impedance of fetal-placental blood flow. Educational objective: Umbilical cord compression impedes fetal-placental blood flow by occluding the umbilical blood vessels. Patients who have umbilical cord compression with ?50% of contractions (as evidenced by recurrent variable decelerations) are at risk of fetal hypoxemia and require intervention with maternal repositioning and possible amnioinfusion. References: Amnioinfusion for potential or suspected umbilical cord compression in labour. (http://www.ncbi.nlm.nih.gov/pubmed/22258939)

Ten Minutes Later, the Fetal Heart Rate Tracing Appears as Shown