Cord prolapse refers to descent of the umbilical cord below the presenting part of the foetus. This is of particular concern as the foetus can then compress its own umbilical cord. It is considered an obstetric emergency as it can cause hypoxia and carries a high mortality rate of almost 10%. Therefore it requires prompt recognition and management.
Pathophysiology
Usually the foetus itself passes through the cervix prior to the umbilical cord. However, with a prolapsed cord, the cord lies below the foetus and passes prior or at the same time as the foetus which can result in 2 things:
- Arterial vasospasm - as the umbilical cord gets exposed to the colder outside atmosphere, vasospasm is induced and there is reduced blood flow to the foetus.
- Compression of the cord - as the foetus presents and descends it then compresses the umbilical cord → occlusion.
Both of these factors lead to reduced blood flow and foetal hypoxia.
The prolapse most commonly occurs during labour but it is possible for it to occur at any point when there is rupture of the membranes. It most commonly occurs after 37 weeks.
⚠️ Risk factors
- Abnormal lie - breech presentation especially provides space for the cord to pass in between the feet and pelvis of the foetus.
- Artificial rupture of membranes (AROM)/amniotomy
- Unstable lie
- Polyhydramnios
- Multiparity
- Prematurity
- Cephalopelvic disproportion
😷 Presentation
It is to always be considered when there is a non-reassuring heart rate after rupture of the membranes. The term “non-reassuring heart rate” refers predominantly to foetal decelerations and potentially even foetal bradycardia that is detected on CTG.
After this is seen the diagnosis may be confirmed via palpation or visualisation of the cord during a vaginal examination after rupture of membranes.
🔍 Investigations
- Cardiotocography
- Vaginal examination/speculum examination
🧰 Management
As discussed in the introduction, it is an obstetric emergency and requires immediate action to prevent foetal hypoxia. There are a couple of things we can/should do:
- If the foetus is presenting → manually elevate the presenting portion of the foetus back into the uterus. This prevents compression of the cord.
- Retrofilling of the bladder with ~500ml of warm saline. This can help further prolapse and helps elevate the presenting part of the foetus.
- Keep cord warm and prevent excessive handling while waiting for delivery. Both of these factors will help avoid arterial vasospasm.
- Position the mother to prevent further prolapse:
- Knee-chest positioning (all fours)
- Alternatively, we can consider the left lateral position.
- Tocolytics can be used to prevent uterine contractions and further presentation of the baby.
- Terbutaline
- ⭐️ Emergency C-section needs to be conducted if the cervix is not fully dilated. However, if the cervix is fully dilated and the head is lying low then we can consider an instrumental delivery.
