Concept
Umbilical cord prolapse is when the umbilical cord comes out of the uterus with or before the presenting part of the baby. The concern with cord prolapse is that pressure on the cord from the baby will compromise blood flow to the baby. It usually occurs during labor but can occur anytime after the rupture of membranes. The greatest risk factors are an abnormal position of the baby within the uterus and a premature or small baby. Other risk factors include a multiple pregnancy, more than one previous delivery, and too much amniotic fluid. Whether medical rupture of the amniotic sac is a risk is controversial. The diagnosis should be suspected if there is a sudden decrease in the baby's heart rate during labor. Seeing or feeling the cord confirms the diagnosis. Management focuses on quick delivery, usually by cesarean section. Filling the bladder or pushing up the baby by hand is recommended until this can take place. Sometimes women will be placed in a knee-chest position or the Trendelenburg position in order to help prevent further cord compression. With appropriate management, the majority of cases have good outcomes. Umbilical cord prolapse occurs in about 1 in 500 pregnancies. The risk of death of the baby is about 10%. However, much of this risk is due to congenital anomalies or prematurity. It is considered an emergency. The first sign of umbilical cord prolapse is usually a sudden and severe decrease in fetal heart rate that does not immediately resolve. On fetal heart tracing (a linear recording of the fetal heart rate) this would usually look like moderate to severe variable decelerations. In overt cord prolapse, the cord can be seen or felt on the vulva or vagina. The main issue with cord prolapse is that, once the cord is prolapsed, it is prone to compression by the foetus and the womb. This can cause decrease in oxygen supply to the foetus which can be fatal. A majority of umbilical cord prolapse cases happen during the second stage of labor.
