In an overt cord prolapse, a loop of umbilical cord is visualized either at the introitus or on sterile speculum examination following membrane rupture. Alternatively, a small loop of cord may be palpated at the cervical os. In a “funic” cord prolapse, a loop of umbilical cord is palpated through intact fetal membranes. Occult prolapse occurs when the umbilical cord descends between the presenting part and the lower uterine segment, but is not visible or palpable on examination. Intermittent compression of the umbilical cord with each uterine contraction may be indicated by variable fetal heart rate and decelerations. Fetal hypoxia may ensue if cord compression is sustained beyond the duration of the contraction, which often happens with overt prolapse.
Umbilical Cord Prolapse. Prolapsed umbilical cord visible at the vaginal introitus in a patient with twin gestations. (Photo contributor: Kevin J. Knoop, MD, MS.)
Management and Disposition
Prolapse of the umbilical cord presents an immediate threat to fetal oxygenation and constitutes a true obstetrical emergency. If an overt prolapse is detected in the ED, do not attempt vaginal delivery. Immediately place the patient in a knee-chest position, consult an obstetrician, and transport the patient directly to the operating room for cesarean delivery. During transport, apply and maintain continuous upward pressure on the fetal presenting part to relieve pressure on the lower uterine segment and cord. Neonatal resuscitative equipment should be available in anticipation of a hypoxic infant.
Pelvic examination to exclude umbilical cord prolapse should be performed immediately following rupture of membranes, appearance of new variable decelerations, or detection of fetal bradycardia.
Rupture of intact membranes with a funic cord may cause or worsen cord prolapse and should never be performed in cases of suspected cord prolapse.
Umbilical Cord Prolapse. Schematic drawing of an overt prolapse of the umbilical cord through a partially dilated cervical os. (Photo contributor: Judy Christensen.)