An umbilical cord prolapse occurs when the umbilical cord drops or prolapses through the cervix and into the vagina before the fetus. The risk factors for an umbilical cord prolapse include:
- Premature rupture of the amniotic membrane
- Excessive amniotic fluid volume
- Abnormal fetal presentation
- A long umbilical cord,
- Prematurity, or
- An unengaged presenting part.
When the umbilical cord prolapses, there is compression of the cord and the flow of oxygen and nutrients to the fetus is interrupted leading to a slowed fetal heart rate or fetal distress.