Cart, Horse, and (ab)normal Events of Delivery
Putting the cart before the horse is a saying that implies that one event occurs before it should. Think of throwing a housewarming party before moving into the house, hiring a wedding photographer before you even propose to your partner, or booking a show for your band before you’ve practiced a single song. These situations are usually due to poor planning; other times, they are situations out of our control. This is what happens during cord prolapse—the events occur in an order that is far from ideal.
During labor, the normal order of events would essentially be:
1. Membranes rupture (water breaks)
2. Baby delivered
3. Umbilical cord management
4. Placenta delivers after birth
How does this order of events change if cord prolapse occurs?
1. Membranes rupture (water breaks)
2. Cord prolapses before delivery of the baby and becomes compressed
3. Emergency ensues
You’ll notice a common theme: following membrane rupture, the presentation will be of either the baby or the umbilical cord (hopefully the baby).
While cord prolapse isn’t common, it is life-threatening for the fetus and requires rapid recognition and management (2). The umbilical cord is the lifeline between the placenta and the fetus. If the cord becomes compressed, circulation to the fetus is so compromised that fetal hypoperfusion and death can be imminent.
Let’s review some vital anatomy, and then we’ll discuss the management of a prolapsed umbilical cord.
Lifeline: Umbilical cord
The umbilical cord spans the distance between the placenta (attached to the uterine wall), through the amniotic sac, and inserts at the umbilicus.
The amniotic sac protects the umbilical cord from entering the cervix and becoming compressed at that location. However, after the rupture of the amniotic sac there is a risk that the cord follows the flow of amniotic fluid through the cervix and into the vaginal canal where it can become compressed. This is one big reason why checking for cord prolapse after the ‘water breaks’ is so essential. Unlike many other obstetric emergencies, cord prolapse is not painful on the maternal side, she may feel as though ‘something' is present, and be completely unaware of the fetal distress that is occurring.
Position and Fluid Volume
Cord prolapse is much less likely if the fetus's head is seated at the cervix. If the head is seated at the cervix when the amniotic sac ruptures, there shouldn’t be any room for the cord to slip by.
However, abnormal fetal positions, such as a breech or transverse lie position, allow much more room for a cord prolapse to occur. When researching cord prolapse, the term ‘presenting part’ is often used. The presenting part can be the head, hips, arm, or leg. When we discuss management, lifting the presenting part will be the first and most essential intervention.
Closely related to position is the volume of fluid inside of the amniotic sac. If the mother has a condition such as gestational diabetes, polyhydramnios (an abnormally high volume of amniotic fluid) may be present (3). This elevated amniotic fluid volume makes it more likely that there will be a cord prolapse due to the increased volume/flow of the discharge - it’s more likely for the cord to be swept away in a large volume of fluid compared to a normal volume.
In addition to Polyhydramnios and breech or transverse fetal positioning, other risk factors include:
1. Premature rupture of membranes
2. Preterm labor
3. Multiple gestation
4. Artificial rupture of membranes
5. Multiparity
Assessment
A vaginal exam post-rupture of membranes is the only sure way to assess for cord prolapse. If the cord prolapsed externally, this exam won’t be very difficult. However, remember that the cord may not be visible externally, so tactile examination may be necessary.
Along with visual and tactile examination, there are other clues that a cord has prolapsed and is compressed. If fetal heart rate monitoring is in place or possible, look for (1):
1. Variable decelerations: Sudden, sharp decreases in fetal heart rate that vary in onset, depth, and duration
2. Prolonged deceleration: Decrease in fetal heart rate lasting 2-10 minutes
3. Fetal bradycardia: Sustained fetal heart rate below 110 bpm
Interventions
Immediate Interventions (4,5):
Manual Elevation: The most critical immediate action is elevating the presenting part off of the cord using a gloved hand. This maneuver must be maintained until definitive care is reached.
Positioning: Place the mother in a left lateral position with hips elevated to reduce pressure on the cord and maintain umbilical blood flow.
Cord Preservation: Use sterile saline-soaked gauze to keep the exposed cord warm and moist. This helps prevent the cord from contracting due to the external environment. Never attempt to replace the cord.
Standard Intrauterine resuscitation: As needed (oxygen, positioning, volume, and tocolysis - see below)
Fetal Monitoring: If equipment is available, continuously assess the fetal heart rate. Be alert for signs of fetal distress.
Rapid Transport and communication: Expedite transfer to a facility capable of emergency cesarean delivery. The provider performing manual elevation may need to accompany the patient on the stretcher. Provide clear, concise handover to the receiving facility, noting the duration of known cord prolapse and interventions performed.
Advanced Considerations:
Bladder Filling: In some cases, filling the maternal bladder via a Foley catheter can help elevate the presenting part. This technique works by using the filled bladder to push the presenting part upward, potentially reducing compression on the cord.
Tocolytics: Under medical direction, tocolytics may be considered to reduce contraction strength and frequency, minimizing cord compression. Common agents include terbutaline and/or magnesium sulfate.
Conclusion
Cord prolapse is a true emergency that requires rapid recognition and management. Unlike some other obstetric emergencies, it can go unrecognized unless clinicians are proactive in their assessment. Cord prolapse is simple in theory - relieve compression on the cord so that the fetus receives circulatory support from the placenta. However, its management has specific interventions that must be performed with careful and strategic manipulation that requires knowledge of the anatomical issues involved.
Hopefully, this blog and the illustrations helped you understand this emergency better!
This topic is taken from a series inside FOAMfrat Studio called Obstetric Icebergs, featuring Demi Wilkes. In it, we discuss these emergencies in detail—a big thanks to Demi for her expert knowledge in this field!
Thanks for reading!
References
Botezatu, R., Gica, N., Peltecu, G., & Panaitescu, A. M. (2022). Umbilical Cord Prolapse - Interesting CTG Traces. Diagnostics (Basel, Switzerland), 12(11), 2845. https://doi.org/10.3390/diagnostics12112845
Boushra M, Stone A, Rathbun KM. Umbilical Cord Prolapse. 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542241/
Hwang DS, Mahdy H. Polyhydramnios. 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK562140/
Sayed Ahmed, W. A., & Hamdy, M. A. (2018). Optimal management of umbilical cord prolapse. International journal of women's health, 10, 459–465. https://doi.org/10.2147/IJWH.S130879
Wong, L., Kwan, A. H. W., Lau, S. L., Sin, W. T. A., & Leung, T. Y. (2021). Umbilical cord prolapse: revisiting its definition and management. American journal of obstetrics and gynecology, 225(4), 357–366. https://doi.org/10.1016/j.ajog.2021.06.077
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