Reproductive · Obstetric Emergencies
The facts most likely to be tested
Umbilical cord prolapse is a true obstetric emergency characterized by the descent of the umbilical cord through the cervix alongside or past the presenting fetal part.
The most common clinical presentation is the sudden onset of severe, prolonged fetal bradycardia or recurrent variable decelerations following artificial rupture of membranes (AROM).
The definitive diagnosis is made by palpation of a pulsating cord on digital vaginal examination.
The most significant risk factor is malpresentation (e.g., breech or transverse lie), especially in the setting of polyhydramnios or prematurity.
Immediate management requires manual elevation of the presenting fetal part to relieve pressure on the cord while preparing for emergent cesarean delivery.
Adjunctive maneuvers to reduce cord compression include maternal knee-to-chest position or Trendelenburg position and bladder filling.
The primary goal is to minimize the decision-to-delivery interval to prevent fetal hypoxia and acidemia.
Vignette unlocked
A 28-year-old G2P1 at 38 weeks gestation undergoes an elective induction of labor. Following artificial rupture of membranes, the fetal heart rate monitor shows a sudden drop from 140 bpm to 70 bpm. On digital vaginal examination, the provider feels a soft, pulsating tubular structure anterior to the fetal head. The fetal head is currently at -2 station.
What is the most appropriate next step in management?
Manual elevation of the presenting fetal part
The patient presents with classic signs of umbilical cord prolapse; the immediate priority is to relieve cord compression by manually lifting the fetal head off the cord while preparing for an emergent cesarean section.
Full handout
High yield triage
Etiology / Epidemiology
Occurs when the cord slips ahead of the presenting part. Malpresentation and artificial rupture of membranes are primary risk factors.
Clinical Manifestations
Sudden onset of severe, prolonged fetal bradycardia or variable decelerations following membrane rupture.
Diagnosis
Diagnosis is clinical via palpation of a pulsating cord in the vagina during a pelvic exam.
Treatment
Immediate manual elevation of the presenting part followed by emergency cesarean section.
Prognosis
Time-sensitive; delay leads to fetal hypoxia and potential neonatal death.
Full handout
Epidemiology & Etiology
Most common in pregnancies with malpresentation (breech, transverse lie) or polyhydramnios. Iatrogenic risk increases significantly following artificial rupture of membranes (AROM), especially if the fetal head is not engaged. Other risks include prematurity and multiparity.
Pertinent Anatomy
The umbilical cord must pass through the cervix before the fetus. If the presenting part does not fully occlude the pelvic inlet, a gap exists where the cord can descend into the vagina.
Pathophysiology
Cord descent leads to mechanical compression between the fetus and the maternal pelvis. This compression causes acute fetal hypoxemia and metabolic acidosis. The resulting fetal bradycardia is a compensatory response to profound oxygen deprivation.
Clinical Manifestations
The hallmark is a sudden, sustained fetal bradycardia or severe variable decelerations immediately following membrane rupture. The provider may palpate a pulsatile cord in the vaginal canal. Fetal death is the ultimate risk if delivery is not achieved rapidly.
Diagnosis
Diagnosis is clinical and made by physical examination. The gold standard is the direct palpation of the umbilical cord in the vagina. Fetal heart rate monitoring will show pathognomonic sustained bradycardia.
Treatment
The first-line intervention is manual elevation of the presenting part to relieve pressure on the cord. The patient should be placed in the knee-chest position or Trendelenburg. Do not attempt to replace the cord into the uterus as this increases risk of vasospasm. Proceed immediately to emergency cesarean section.
Prognosis
Prognosis is excellent if delivery occurs within 10-12 minutes. Prolonged compression leads to hypoxic-ischemic encephalopathy or fetal demise. Continuous fetal heart rate monitoring is mandatory until the fetus is delivered.
Differential Diagnosis
Placental abruption: presents with painful vaginal bleeding and uterine hypertonicity
Uterine rupture: associated with loss of fetal station and severe maternal abdominal pain
Vasa previa: painless vaginal bleeding with fetal bradycardia upon membrane rupture
Fetal head compression: typically causes early decelerations, not sustained bradycardia
Nuchal cord: usually diagnosed at delivery, rarely causes sustained intrapartum bradycardia