A nuchal cord describes a situation where the umbilical cord is wrapped around a baby’s neck. While the idea might sound alarming to expectant parents, this occurrence is quite common, affecting approximately 10% to 30% of pregnancies. Despite its frequency, a nuchal cord rarely leads to serious complications for the baby.
Understanding Nuchal Cords
The term “nuchal” refers to the neck, indicating the umbilical cord’s position around this area. This is a common finding.
Several factors can contribute to a nuchal cord. Normal fetal movement within the womb is a primary cause, as babies are active and can unintentionally entangle themselves. A longer than average umbilical cord, typically exceeding 32 inches, also increases the likelihood of wraps or even true knots forming. Additionally, an abundance of amniotic fluid, known as polyhydramnios, can provide more space for a baby to move and potentially wrap the cord around themselves.
How Nuchal Cords are Identified
Parents generally cannot detect a nuchal cord on their own. Medical professionals most commonly identify its presence during routine prenatal ultrasounds. Even if detected, healthcare providers may not always report the finding, as nuchal cords are frequent and often considered a normal variation as long as blood flow is adequate.
In many instances, a nuchal cord is first discovered during labor and delivery. Healthcare providers routinely check for the cord around the baby’s neck once the head has emerged. Concerns about the baby’s well-being, such as unusual fetal heart rate patterns, might prompt closer monitoring or investigation.
Potential Concerns and Realities
Many nuchal cords are loose and do not pose a danger because babies do not breathe air in the womb. Instead, they receive all necessary oxygen and nutrients through the umbilical cord from the placenta. The umbilical cord is also protected by a gelatinous substance called Wharton’s Jelly. This protective tissue helps prevent the blood vessels within the cord from becoming compressed, even if the cord is wrapped or knotted.
Rarely, a nuchal cord might be tightly wrapped, potentially affecting blood flow or causing temporary changes in the fetal heart rate during labor. These changes are often seen as “variable decelerations” on a fetal heart rate monitor, indicating a temporary drop in the baby’s heart rate. Healthcare providers closely monitor these patterns to assess the baby’s tolerance to labor. While complications are uncommon, a tight nuchal cord could lead to issues like reduced oxygen supply or, in very rare cases, conditions such as acidosis or anemia. Medical teams are prepared to identify and manage these occurrences to ensure the baby’s safety.
What Happens During Delivery
During labor and delivery, healthcare providers are well-versed in managing nuchal cords. Once the baby’s head is delivered, the care team will feel for the umbilical cord around the neck. If the cord is loose, it can typically be gently slipped over the baby’s head, allowing delivery to proceed without interruption.
If the cord is too tight to be slipped over the head, the provider might employ other maneuvers, such as the somersault maneuver, to facilitate delivery. Alternatively, the cord may need to be clamped and cut before the rest of the baby’s body is delivered. Nuchal cords cannot be prevented by any actions taken during pregnancy. Healthcare teams are highly experienced and equipped to manage nuchal cords, ensuring a safe delivery for most babies.