Umbilical cord prolapse
|Umbilical cord prolapse|
|Classification and external resources|
Cord prolapse, depicted by W.Smellie, 1792
Umbilical cord prolapse happens when the umbilical cord precedes the fetus' exit from the uterus. It is an obstetric emergency during pregnancy or labor that imminently endangers the life of the fetus. Cord prolapse is rare. Statistics on cord prolapse vary, but the range is between 0.14% and 0.62% of all births in most studies.
Cord prolapse is often concurrent with the rupture of the amniotic sac. After this happens the fetus moves downward into the pelvis and puts pressure on the cord. As a result, oxygen and blood supplies to the fetus are diminished or cut-off and the baby must be delivered quickly.
Treatment and mortality rate
Some practitioners will attempt to reduce pressure on the cord and deliver vaginally right away. Frequently the attempt to resolve the prolapsed cord and deliver the baby vaginally fails, and an emergency caesarean section must be performed immediately. While the patient is being prepared for a caesarean, the woman is placed in the Trendelenburg position or the knee-elbow position, and an attendant reaches into the vagina and pushes the presenting part out of the pelvic inlet and back into the pelvis to remove the pressure from the umbilical cord. If attempts to deliver the baby promptly fail, the fetus' oxygen and blood supply are occluded and brain damage or death will occur.
The mortality rate for the fetus is given as 11–17%. This applies to hospital births or very quick transfers in a first world environment. One series is reported where there was no mortality in 24 cases with the novel intervention of infusing 500ml of fluid by catheter into the woman's bladder, in order to displace the presenting part of the fetus upward, and to reduce compression on the prolapsed cord; however a recent trial comparing manual support alone (n=29) versus manual support plus bladder-filling (n=15) showed no added benefit in terms of neonatal outcome.
Potential predisposing risk factors include:
- Premature rupture of the amniotic sac
- polyhydramnios (having a large volume of amniotic fluid). The cord may be forced out with the more forceful gush of waters.
- long umbilical cord
- fetal malpresentation
- multiple gestation
- http://www.gpnotebook.co.uk/simplepage.cfm?ID=1785397303 GP Notebook. Mortality 11-17%.