Umbilical Cord Prolapse

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Diagnosis and reasoning

This lady has presented with umbilical cord prolapse (UCP), an obstetric emergency. At this point, the first and most important question is : "is the fetus still alive ?". This will determine the further management. The presence of cord pulsations indicates a live fetus. This is confirmed by doppler auscultation. In addition, examination shows her to be in the first stage of labor. As the fetus is viable, delivery should be performed as soon as possible. After obtaining IV access and sending blood for grouping and cross matching, she should be rushed to the operating theatre for caesarean section. Note that vacuum extraction is not advisable, as the head is high and the cervix is only partially dilated. In UCP, each and every second counts. As there will invariably be some degree of delay until surgery, various strategies may be used to "buy time". Placing the patient in the knee-chest position will displace the presenting part upwards, as will infusion of saline into the bladder. This will relieve cord compression. Insertion of a warm saline swab into the vagina will both cushion the cord from the presenting part and prevent vasospam of the umbilical vessels (which may be precipitated by the relatively cold environment in the vagina). Transvaginal ultrasonography should not be performed, as this may irritate the cord and provoke vasospasm. Cardiotocography will result in unnecessary delay.


Discussion

Umbilical cord prolapse (UCP) is defined as descent of the umbilical cord through the cervix alongside or past the presenting part, in the presence of ruptured membranes. It is uncommon, affecting between 0.1% to 0.6% of all births. The overall perinatal mortality rate is as high as 9.1% Cord presentation is the presence of the umbilical cord between the fetal presenting part and the cervix, without membrane rupture. In UCP, the prolapsed cord is compressed by the presenting part, compromising blood flow. This may be further exacerbated by vasospasm of the umbilical vesels. This culminates in fetal asphyxia, hypoxic ischemic encephalopathy and ultimately, intrauterine death. Any obstetric condition preventing close application of the presenting part to the lower part of the uterus predisposes towards UCP. Predisposing fetal conditions include breech presentation, unengaged high head, unstable lie, multiple gestations and congenital malformations. Predisposing maternal conditions include polyhydramnios, uterine fibroids, uterine anomalies and a low-lying placenta. Obstetric manipulations such as artificial rupture of membranes, external cephalic version and insertion of a uterine pressure transducer may also predispose towards UCP. Detection of UCP may be very tricky. The possibility should be kept in mind in patients with predisposing factors who manifest reduced fetal movements or prolonged fetal bradycardia following rupture of the membranes. The presence of repetitive moderate to severe variable decelerations in the cardiotocogram is another clue towards the diagnosis. UCP is confirmed when the umbilical cord is palpated in the vagina below the presenting part. As mentioned above, after diagnosis, the next step is to assess fetal viability. The presence of cord pulsations indicates a live fetus - but does not necessarily indicate adequate blood flow. In addition, the absence of cord pulsations does not necessarily indicate fetal demise - doppler auscultation should be performed for confirmation. Further investigations are mostly unnecessary and may result in delay of treatment. If the fetus is viable, delivery should be performed as soon as possible. If the patient is in the second stage of labor (i.e. a fully dilated cervix and engaged presenting part), operative vaginal delivery should be performed. In all other cases, emergency caesarian section is the treatment of choice. If the fetus is non-viable, urgent delivery is not indicated. However, conditions such as a transverse lie may still warrant caesarian section later on. If surgery is expected to be delayed, blood flow through the cord may be maintained via strategies such as manual elevation of the presenting part, assumption of the knee-chest position or head-down tilt, instillation of fluid into the bladder, insertion of a warm saline pack into the vagina, and tocolysis via terbutalin. Note that manual replacement of the prolapsed cord is ill advised, as this may induce intense vasospasm of the umbilical vessels. A pediatrician should be present at delivery as resuscitation of the newborn is often required. Neonatal ICU facilities may also be needed. The most important factor affecting outcome is the interval between diagnosis to delivery. Longer intervals are associated with lower Apgar scores.


Take home messages

  1. UCP is an obstetric emergency where each and every second counts.
  2. Reduced fetal movements, bradycardia or variable fetal heart rate decelerations in a patient with predisposing factors should alert the clinician to the possibility of UCP.
  3. If the fetus is viable, emergency delivery is the treatment of choice.
  4. Where delay is expected, cord blood flow may be maintained by elevation of the presenting part, assumption of the knee-chest position, infusion of saline into the bladder, warm vaginal saline packs and tocolysis.
  5. The umbilical cord should not be handled manually as this may induce intense vasospasm.

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  1. J Emerg Med. 1989 Mar-Apr;7(2):149-52. Umbilical cord prolapse: a true obstetrical emergency. Barnett WM.
  2. Journal of Reproductive Medicine. 2005 50(5):303-6. Umbilical cord prolapse in current obstetric practice. Boyle JJ, Katz VL
  3. Obstet Gynecol Surv. 4/2006;61(4):269-77. Umbilical cord prolapse. Lin MG.
  4. Royal College of Obstetricians and Gynaecologists. Green-top Guideline No. 50 - Umbilical Cord Prolapse. April 2008.