A multiparous patient (G3P2) at 39 weeks of gestation is evaluated in the labor unit. She … — USMLE Step 2 CK

A multiparous patient (G3P2) at $39$ weeks of gestation is evaluated in the labor unit. She is experiencing painful uterine contractions every $3$ minutes. Her pregnancy has been uncomplicated. Her temperature is $37.1^\circ\text{C}$ ( $98.8^\circ\text{F}$ ), blood pressure is $118/76\text{ mmHg}$ , and pulse is $82\text{/min}$ . The baseline fetal heart rate is $140\text{/min}$ with moderate variability and no decelerations. A cervical examination reveals $6\text{ cm}$ dilation, $80\%$ effacement, and the fetal vertex is at a $-2$ station. The physician performs an artificial rupture of membranes to augment labor. Immediately following the procedure, the continuous electronic fetal monitor reveals an abrupt decrease in the fetal heart rate to $70\text{/min}$ that persists for $3$ minutes. A repeat digital pelvic examination identifies a soft, compressible, pulsatile mass in the vaginal vault ahead of the fetal presenting part. Which of the following is the most appropriate next step in the management of this patient?

A
Carefully push the palpable mass back through the cervix into the uterine cavity
B
Continue expectantly as this is a benign physiologic vagal response to amniotomy
Digitally elevate the fetal vertex and prepare the patient for an emergency abdominal deliveryAnswer
D
Perform an immediate operative vaginal extraction of the fetus
E
Turn the patient to the left lateral position and administer an intravenous fluid bolus

Answer

The most appropriate next step is to digitally elevate the fetal vertex and prepare the patient for an emergency abdominal delivery (cesarean section).

The correct answer involves manually elevating the fetal presenting part to relieve pressure on the prolapsed umbilical cord, followed by an immediate abdominal delivery (cesarean section). This patient is presenting with an umbilical cord prolapse, a life-threatening obstetric emergency that typically occurs after the rupture of membranes when the fetal presenting part is unengaged (e.g., at a high station such as

-2

). The prolapsed cord becomes compressed between the fetal head and the maternal pelvis, leading to severe fetal hypoxia, which manifests as a sudden, prolonged fetal bradycardia. Immediate management requires relieving the compression by keeping a hand in the vagina to push the fetal head upward while concurrently mobilizing the surgical team for an emergency cesarean section.

Step-by-Step Solution

Identify the obstetric emergency based on the clinical presentation.

The patient has suffered an umbilical cord prolapse, characterized by a sudden, prolonged fetal bradycardia (

70\text{/min}

) immediately following artificial rupture of membranes, along with a palpable, pulsatile vaginal mass.

Rupturing membranes when the fetal head is high (

-2

station) allows the umbilical cord to slip past the presenting part, leading to mechanical compression.

Determine the immediate life-saving intervention for this condition.

The mechanical compression on the umbilical cord must be relieved manually by continuously elevating the fetal head.

Cord compression obstructs fetal blood flow, causing rapid and severe hypoxia. Relieving this physical pressure is the only way to temporarily restore fetal oxygenation.

Select the definitive mode of delivery.

An emergency abdominal delivery (cesarean section) is indicated.

Vaginal delivery is not imminent or safe given the high fetal station and the active cord prolapse, necessitating immediate surgical intervention.

Key Concept

Management of Umbilical Cord Prolapse

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