The umbilical cord acts as a baby’s lifeline within the womb, delivering oxygen, blood, and nutrients from the mother to the developing fetus. This flexible, tube-like structure typically contains two arteries and one vein, stretching from the baby’s abdomen to the placenta. While its primary role is to sustain the baby, the cord can sometimes wrap around the baby’s body, a situation that often raises questions for expectant parents.
How Common is Cord Wrapping
Umbilical cord wraps are a common occurrence during pregnancy and delivery. Specifically, a nuchal cord, where the cord wraps around the baby’s neck, is observed in about 20% to 30% of all deliveries. The incidence of nuchal cords tends to increase as pregnancy progresses, with rates around 12% at 24–26 weeks and reaching approximately 37% at full term. In most instances, this wrapping does not pose a problem for the baby, and it is frequently discovered only at the time of birth.
Understanding Why Cords Wrap
Fetal movement is a primary reason why umbilical cords can become wrapped around a baby. Active babies in the womb can cause the cord to coil around their body.
The length of the umbilical cord also plays a role. A longer cord, typically 20-24 inches but sometimes exceeding 32 inches, provides more opportunity for entanglement. Additionally, an abundance of amniotic fluid, known as polyhydramnios, allows the baby greater mobility, increasing the chances of cord wrapping.
While nuchal cords (around the neck) are the most recognized type, the cord can also entangle other body parts or form a true knot. Multiple pregnancies, such as twins or triplets, also increase the likelihood of cord wrapping due to more babies sharing the space.
What Happens When Cords Wrap
Most umbilical cord wraps are benign and do not lead to complications. The umbilical cord contains a protective, jelly-like substance called Wharton’s Jelly, which helps prevent vessel compression, even with multiple loops. Healthcare professionals monitor for potential issues during routine ultrasounds and continuously during labor through fetal heart rate monitoring. Variable decelerations, temporary drops in fetal heart rate, can indicate blood flow blockage or cord compression, prompting quick action.
In rare instances where a cord wrap causes complications like reduced blood flow or oxygen supply, interventions may be considered. Changing the mother’s position or providing supplemental oxygen can alleviate pressure and improve blood flow. If the cord is loose at delivery, it can be slipped over the baby’s head; if too tight, it may be clamped and cut before delivery. In very rare cases of fetal distress, a Cesarean section (C-section) might be necessary. Serious complications are uncommon, and medical teams are well-prepared to manage such situations.