The umbilical cord can sometimes wrap around the fetus’s neck, a condition known as a nuchal cord. This occurrence is common, affecting approximately 10% to 37% of pregnancies by the time of delivery. Although the phrase “cord around the neck” may sound alarming, a nuchal cord is often a transient and harmless finding that requires close monitoring. Awareness of the underlying biology and potential changes in fetal behavior is important for expectant parents to understand when to consult their healthcare provider.
Understanding the Nuchal Cord
A nuchal cord describes the umbilical cord wrapping 360 degrees around the fetal neck one or more times. The term “nuchal” refers to the neck or nape area. The primary mechanism leading to this entanglement is the fetus’s natural movement within the amniotic fluid. Factors like an unusually long umbilical cord or an excessive amount of amniotic fluid can increase the likelihood of the cord forming a loop around the neck.
The loops are classified based on their tightness and mobility. A loose nuchal cord (Type A or unlocked) can slide freely and may spontaneously unwrap before birth due to ongoing fetal movement. A tight nuchal cord (Type B) does not easily slip off and is more likely to cause complications because of compression. Most nuchal cords found during pregnancy are loose and do not pose a significant risk to the baby’s well-being.
Key Signs to Monitor Before Delivery
Parents cannot physically feel or self-diagnose a nuchal cord, as the condition produces no distinct physical symptoms in the mother. The most important indicator parents can monitor at home is a change in the baby’s movement patterns, which serves as a general sign of fetal distress. Tracking the frequency and strength of kicks, known as “kick counting,” is a method for monitoring fetal health.
A concerning change is a sudden, sustained decrease in the frequency of fetal movement, such as the baby moving significantly less than their established routine. Another pattern to watch for is a brief period of unusually frantic or forceful movement, followed by a noticeable period of silence or reduced activity. This rapid shift may represent the baby attempting to free itself from a restriction. Any significant deviation from the baby’s normal movement pattern warrants immediate contact with a healthcare provider for a professional evaluation.
How Medical Professionals Manage the Condition
Medical professionals typically diagnose a nuchal cord during a routine prenatal ultrasound, though it is often discovered during labor. Once labor begins, the primary tool for monitoring fetal well-being is continuous electronic fetal heart rate monitoring. This monitoring is sensitive to changes in blood flow through the umbilical cord, which can be affected by a tight wrap.
A key sign of potential cord compression is the presence of “variable decelerations,” which are temporary drops in the fetal heart rate below the baseline. These decelerations suggest a transient blockage of blood flow through the umbilical vessels, and a nuchal cord is one possible cause. During vaginal delivery, the healthcare team checks for the cord around the baby’s neck as soon as the head is delivered.
If the cord is loose, the provider will gently slip the loop over the baby’s head to allow the rest of the body to deliver normally. If the cord is too tight to slip over the head, a specific technique called the “somersault maneuver” may be used, where the baby’s head is kept close to the perineum while the shoulders and body are delivered through the loop. If the cord is extremely tight and cannot be unwrapped, the provider will clamp the cord in two places and cut it before the rest of the baby’s body is delivered.