Umbilical Cord Prolapse — Bedside Emergency Management Protocol

Overview

Umbilical cord prolapse is the descent of the umbilical cord ahead of (overt type) or alongside (occult type) the fetal presenting part along the cervix in the presence of membrane rupture. When cord loops are subjected to pressure on the presenting part and cold air or vaginal examination, both mechanical compression and vasospasm in the umbilical artery occur; this dual mechanism interrupts umbilical blood flow, resulting in sudden fetal bradycardia, hypoxia, and, if untreated, fetal death.

The incidence is approximately 1-6 per thousand births (reported as 1.4-6.2 per thousand in some series), and this rate increases to 1-6% in breech or other malpresentations. Known risk factors include fetal malpresentation or abnormal lie, prematurity, multiple gestation, polyhydramnios, and premature rupture of membranes; polyhydramnios increases risk both by causing malpresentation and by preventing the presenting part from engaging in the pelvis, and the risk associated with prematurity predominantly operates through concurrent malpresentation.

In twin pregnancies, cord prolapse is significantly more frequent in the second twin because the uterus rapidly empties after the birth of the first twin and the membranes may rupture before the presenting part of the second twin has engaged in the pelvis. About half of the cases are iatrogenic; the most common cause is amniotomy performed when the presenting part has not yet engaged or is high, so if membrane rupture is necessary with a high presenting part, the procedure should only be performed when full preparation for emergency cesarean section is in place.

Diagnosis is clinical and time-critical: when sudden or prolonged bradycardia or recurrent variable decelerations develop after ROM, the cord should be immediately sought via vaginal examination; fetal heart rate (FHR) changes are found in approximately 40-60% of cases, and the absence of this finding does not exclude the diagnosis. Inability to palpate the cord does not rule out occult prolapse; this type may only manifest through recurrent variable decelerations and is generally recognized during or after cesarean section.

When the membranes are intact and the cord is located in front of the presenting part, it is called cord presentation (funic presentation); this is not yet a prolapse, but when detected by transvaginal ultrasonography, it is a warning sign that amniotomy should be avoided and a cesarean section should be planned. Distinguishing funic presentation from vasa previa is possible with transvaginal ultrasonography, because when the mother coughs or the fetus moves, the free cord loop shifts while the vessel in vasa previa remains fixed; the sensitivity of transvaginal ultrasonography with color Doppler for the diagnosis of vasa previa has been reported to be about 93-100% and specificity about 99%.

The essence of management is to immediately relieve cord pressure and deliver the fetus by the fastest safe route; perinatal mortality in cord prolapse outside the hospital is approximately 18 times higher than in in-hospital cases, highlighting the importance of early diagnosis and emergency transfer. Perinatal mortality rates reported in large series vary greatly according to geography and level of care; while it is about 6-10% in high-income countries, it rises to 23-27% in low-income countries, and mortality decreases to about 3% in cases managed promptly in a hospital but has been reported up to 44% in out-of-hospital births.

In a national register study in Sweden covering 2014-2020, which included 607,123 births (Tallhage et al., 2024), the incidence of cord prolapse in 230,699 births with amniotomy was found to be 1.3 per thousand (293 cases), and in 376,424 cases born with spontaneous membrane rupture, it was 1.2 per thousand (458 cases). In this study, common risk factors for both amniotomy and spontaneous rupture were high parity, non-cephalic presentation, and induction of labor, whereas previous cesarean section and polyhydramnios were only associated with amniotomy, and advanced gestational age was identified as a factor reducing risk.

Key considerations

• Uterine tachysystole or hyperstimulation can lead to sudden fetal bradycardia or recurrent late decelerations; however, in this condition, the cord is not palpable on vaginal examination, and fetal heart rate usually improves with tocolysis.
• Placental abruption causes fetal bradycardia along with sudden severe abdominal pain, vaginal bleeding, and a firm/tender uterus; unlike cord prolapse, a pulsating cord is not found on vaginal examination.
• Uterine rupture, especially in a pregnant woman with a previous cesarean scar, presents with sudden fetal bradycardia, abdominal pain, vaginal bleeding, and sudden cessation of contractions, and requires emergency laparotomy.
• Maternal hypotension, particularly following epidural or spinal anesthesia, leads to transient fetal bradycardia due to decreased uteroplacental perfusion and usually resolves quickly once maternal blood pressure is corrected (fluids, position change, ephedrine/phenylephrine if necessary).
• Vasa previa is a condition in which fetal vessels pass over the cervix within the membranes and rupture with membrane rupture, causing acute fetal distress accompanied by painless vaginal bleeding; unlike cord prolapse, the cord is not palpable on vaginal examination, and the bleeding is fetal in origin, which can rapidly progress to fetal exsanguination.
• In occult (hidden) cord prolapse, the cord is trapped beside the presenting part and cannot be palpated on vaginal examination; diagnosis is only made through recurrent variable decelerations or observed directly during cesarean section.
• Cord presentation (funic presentation) is when the cord lies in front of the presenting part while the membranes are intact; prolapse has not yet occurred and can be detected antenatally by transvaginal ultrasonography, but it can turn into overt prolapse as soon as the membranes rupture.
• Benign and transient variable decelerations observed during labor are generally due to head pressure or temporary, self-limiting cord compression; the cord is not palpable on vaginal examination, and the decelerations resolve with a change in position.
• Fetal arrhythmia or congenital heart block may falsely mimic bradycardia as an abrupt irregular or very low heart rate on the monitor; differentiation requires fetal echocardiography or direct auscultation.

Why it matters

There are two mechanisms of fetal injury in cord prolapse: mechanical compression of the cord between the presenting part and the bony pelvis, and umbilical artery vasospasm due to cold air or manipulation; both interrupt fetal oxygenation. The Royal College of Obstetricians and Gynaecologists (RCOG) Green-top Guideline No.

50 (2014, revised) recommends that if rupture of membranes is necessary with a high presenting part, it should only be performed when ready for an emergency cesarean, and that upward pressure on the presenting part should be avoided during vaginal examination and other obstetric interventions, as this may cause the presenting part to rise and predispose to cord prolapse. The same guideline recommends that high-risk pregnancies be monitored in the hospital after membrane rupture; this minimizes diagnostic delay and decision-to-delivery interval.

Therefore, the first and most effective intervention in the protocol is to lift the cord compression by manually elevating the presenting part; it is essential to handle the cord minimally and keep it warm and moist, as funic reduction (replacing the cord back into the vagina) has been abandoned due to increased vasospasm and recurrence. The review by Wong et al. (Am J Obstet Gynecol, 2021) and the measurement study by Kwan et al. using transperineal ultrasound (Ultrasound Obstet Gynecol, 2021) compared the effects of maneuvers on elevating the presenting part: the knee-chest position provides the greatest elevation effect, followed by bladder filling with 500 mL, then 300 mL of isotonic saline; in contrast, bladder filling with 100 mL, a 15-degree Trendelenburg position, and lifting only the maternal hips were found to have limited effect.

This finding supports emphasizing the knee-chest position as the primary option in the protocol and considers low-degree Trendelenburg alone insufficient. Bladder filling produces similar results to manual elevation when not in imminent labor or during short transfers (RCOG GTG No.

50), but it should be emptied immediately before delivery to avoid obstructing birth. If contractions are present, tocolysis with 0.25 mg (250 micrograms) subcutaneous terbutaline suppresses uterine activity and alleviates cord compression and bradycardia (intrauterine resuscitation); however, tocolysis does not delay delivery and is performed concurrently with cesarean preparation.

The definite treatment is rapid delivery: RCOG recommends that in the presence of suspected or pathological FHR, the decision-to-delivery interval should be kept under 30 minutes; however, published audit series show that going below this 30-minute threshold does not additionally improve neonatal outcomes, whereas prolonging the interval is risky; in some series, despite decision-to-delivery intervals exceeding 30 minutes, fetal loss has not been reported, suggesting that timely and systematic management is more important than any single minute threshold.

If there is full dilation and delivery is imminent, instrumental vaginal delivery is usually preferred to avoid pressure on the cord. The previously taught funic reduction (manually pushing the cord back into the vagina) is now abandoned, as the risk of vasospasm and recurrent prolapse triggered by the manipulation outweighs the theoretical benefit.

The finding that mortality in out-of-hospital prolapse is approximately 18 times higher than in in-hospital cases justifies lifting the pressure and urgent transfer to the nearest cesarean-capable center.

Critical complications

• Fetal hypoxic-ischemic encephalopathy develops as a result of prolonged cord compression or vasospasm; it is recognized at birth with a low Apgar score and acidotic umbilical cord blood gases, and if the newborn meets the criteria for intensive care cooling, it is managed with therapeutic hypothermia. Published reviews report that the rate of neonatal encephalopathy after cord prolapse is approximately 2% and the rate of cerebral palsy is approximately 0.43%; therefore, neurological examination and imaging if necessary should continue in the first days after birth.
• Perinatal death occurs particularly in out-of-hospital births or when the decision-to-delivery interval is prolonged and the diagnosis is delayed; the most effective measure is immediate removal of cord pressure and acceleration of delivery.
• Maternal complications related to Category-1 emergency cesarean (bleeding, uterine atony, wound infection, anesthesia complications) may increase due to urgency; this risk is reduced by prophylaxis against bleeding during rapid preparation and by having uterotonic agents ready in advance.
• The need for general anesthesia and the associated maternal aspiration risk may arise when an extremely short decision-to-delivery interval is targeted and there is no time for regional anesthesia; rapid sequence induction protocols and an experienced anesthesia team reduce this risk.
• During manual elevation, excessive or prolonged vaginal manipulation can lead to additional vasospasm in the cord and iatrogenic trauma; therefore, it should be ensured that only the presenting part is pushed by the hand and the cord is not directly compressed.
• When the bladder is overfilled, the risk of maternal discomfort and, rarely, complications due to bladder distension increases; therefore, the 500-750 mL limit should be observed and the bladder should be emptied just before delivery.
• Recurrent (recurrent) cord prolapse has been reported especially after abandoned funic reduction application; therefore, replacing the cord is no longer recommended.
• In the newborn, anemia and hypovolemic shock can develop when prolonged cord compression or accompanying cord rupture/vasa previa occurs; at delivery, the cord is evaluated with blood gas analysis and complete blood count, and if necessary, a blood transfusion is administered to the newborn.

Special considerations

• In multiple pregnancy, especially in the second twin, cord prolapse is significantly more frequent because after the birth of the first twin, the uterus suddenly empties and the membranes may rupture before the presenting part of the second twin has settled into the pelvis; therefore, during the delivery of the second twin, immediate fetal heart monitoring and cord assessment via vaginal examination are recommended after membrane rupture.
• Cord prolapse is more common in preterm pregnancy because the premature fetus generally has not fully settled into the pelvis and the incidence of accompanying malpresentation is high; additionally, since a preterm newborn’s tolerance to hypoxia is lower than that of a term newborn, the same duration of cord compression can leave more severe sequelae.
• In a patient with polyhydramnios, sudden and high-volume amniotic fluid flow during membrane rupture can drag the cord along with the presenting part if it has not yet engaged; therefore, in polyhydramnios, amniotomy should be performed in a controlled and slow manner, and if possible, controlled amniotomy with a needle is preferred.
• In cases of malpresentation (breech, transverse lie, high head), the risk of cord prolapse increases significantly because the presenting part cannot fully occupy the pelvic inlet and space remains through which the cord can pass; in these pregnancies, the decision for membrane rupture and the indication for amniotomy should be evaluated more cautiously.
• The risk of cord prolapse in women undergoing labor induction and in high-parity (having given birth multiple times) pregnancies has been found to be increased both in births with amniotomy and in births with spontaneous membrane rupture (Tallhage et al., 2024); therefore, in a pregnancy planned for induction, it should be assessed whether the presenting part has engaged in the pelvis before membrane rupture.
• Around the threshold of viability (approximately 23-24 weeks), in the presence of intrauterine fetal death or lethal anomalies incompatible with life, a wait-and-see approach individualized and decided together with the family may be appropriate instead of an emergency cesarean; this decision should be shaped according to the gestational week, institutional protocol, and the family's preference.
• When cord prolapse occurs outside the hospital setting (home birth, ambulance, before presenting to the emergency department), perinatal mortality is approximately 18 times higher than in in-hospital cases; therefore, relieving cord pressure and positioning should be immediately applied, and emergency transfer to the nearest facility capable of performing cesarean section should be initiated without delay.
• When cord prolapse develops in a woman with a previous cesarean scar, uterine rupture must always be considered in the differential diagnosis, as both conditions cause sudden fetal bradycardia; however, the management approach (emergency delivery) is similarly urgent in both cases. A history of previous cesarean was found in the Swedish national registry study (Tallhage et al., 2024) to be an independent factor that increases the risk of cord prolapse only in membrane rupture performed via amniotomy; therefore, the decision for amniotomy in a woman with a previous cesarean should not be made without confirming the engagement of the presenting part.

Follow-up plan

The neonatal resuscitation team should be present at birth; cord arterial and venous blood gas should be taken, and the Apgar score should be recorded at 1 and 5 minutes. The newborn is closely monitored in the first hours for signs of hypoxic-ischemic encephalopathy; if clinical and laboratory criteria are met, evaluation for therapeutic hypothermia is performed or the patient is referred to a center that offers this treatment.

The mother is monitored in the postpartum period for complications of emergency cesarean or general anesthesia (bleeding, uterine atony, anesthesia-related issues). Detailed documentation of the event is critical for both clinical follow-up and potential legal processes: time of diagnosis/announcement, time of relieving cord compression, maneuvers and positions applied, bladder filling volume and timing, tocolysis application, decision-to-delivery interval (in minutes), type of anesthesia, and the newborn’s condition (cord blood gas, Apgar scores, need for resuscitation) should be recorded.

Before discharge, the mother and family should be clearly informed about the neurological follow-up plan of the newborn, developmental assessment appointments if necessary, and the cause of the event. During planning for the next pregnancy, women with a history of cord prolapse should be evaluated early for recurring risk factors (malpresentation, polyhydramnios) and the birth plan should be adjusted accordingly.

At the institutional level, regular team simulation training (cord prolapse drills) should be maintained, as it shortens the decision-to-delivery interval and improves neonatal outcomes.