Umbilical cord prolapse

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. ==Risk factors==

Risk factors that are associated with umbilical cord prolapse tend to make it difficult for the baby from appropriately engaging and filling the maternal pelvis or are related to abnormalities of the umbilical cord. The two major categories of risk factors are spontaneous and iatrogenic (those that result from medical intervention). • spontaneous factors: • fetal malpresentation: abnormal fetal lie tends to result in space below the baby in the maternal pelvis, which can then be occupied by the cord. • polyhydramnios, or an abnormally high amount of amniotic fluid usually described as <2500g at birth, though some studies will use <1500g. Cause is likely similar to those for prematurity. • multiple gestation, or being pregnant with more than one baby at a given time: about half of prolapses occur within 5 minutes of membrane rupture, two-thirds within 1 hour, 95% within 24 hours. • treatment associated factors: • artificial rupture of membranes • placement of internal monitors (for example, internal scalp electrode or intrauterine pressure catheter) • manual rotation of fetal head ==Diagnosis==

Umbilical cord prolapse should always be considered a possibility when there is a sudden decrease in fetal heart rate or variable decelerations, particularly after the rupture of membranes. With overt prolapses, the diagnosis can be confirmed if the cord can be felt on vaginal examination. Without overt prolapse, the diagnosis can only be confirmed after a cesarean section, though even then it will not always be evident at time of procedure. • overt umbilical cord prolapse: descent of the umbilical cord past the presenting fetal part. In this case, the cord is through the cervix and into or beyond the vagina. Overt umbilical cord prolapse requires rupture of membranes. This is the most common type of cord prolapse. • occult umbilical prolapse: descent of the umbilical cord alongside the presenting fetal part, but has not advanced past the presenting fetal part. Occult umbilical prolapse can occur with both intact or ruptured membranes. • funic (cord) presentation: presence of the umbilical cord between the presenting fetal part and fetal membranes. In this case, the cord has not passed the opening of the cervix. In funic presentation, the membranes are not yet ruptured. ==Management==

File:Herself; talks with women concerning themselves (1911) (14781210692).jpg|thumb|The knee-chest position is typically recommended If the mother is far from delivery, funic reduction (manually placing the cord back into the uterine cavity) has been attempted, with successful cases reported. However, this is not currently recommended by the Royal College of Obstetricians and Gynaecologists (RCOG), as there is insufficient evidence to support this maneuver. ==Outcomes==

The primary concern with umbilical cord prolapse is inadequate blood supply, and thus oxygen, to the baby if the cord becomes compressed. The cord can become compressed either due to mechanical pressure (usually from the presenting fetal part) or from sudden contraction of the vessels due to decreased temperatures in the vagina in comparison to the uterus. However, these estimates occurred in the context of home or births outside of the hospital. When considering cord prolapses that have occurred in inpatient labor and delivery settings, the rate drops to as low as 0-3%, ==Epidemiology==

Rates of umbilical cord prolapse ranges from 0.1 to 0.6% of all pregnancies. This rate has remained stable over time. A recent study estimates 77% of cord prolapses occur in singleton pregnancies (where there is only one baby). In twin pregnancies, cord prolapses occur more frequently in the second twin to be delivered, with 9% in the first twin and 14% in the second twin. == References ==