Nuchal Cord: Umbilical Cord Wrapped Around Baby’s Neck

A nuchal cord is a complication that occurs when the umbilical cord wraps around the baby’s neck one or more times. Nuchal cords are common and occur in about 15-35% of pregnancies. Often, nuchal cords do not impact pregnancy outcomes. However, certain types of nuchal cords can pose a significant risk to the baby.

Nuchal cords can interrupt normal blood, nutrients, and oxygen exchange, which can lead to a variety of birth injuries, including hypoxic-ischemic encephalopathy (HIE), a form of brain damage caused by oxygen deprivation around the time of birth. If a nuchal cord is present, doctors should carefully monitor and manage the condition. In some cases, babies with a nuchal cord may still be delivered vaginally (there are specific maneuvers that can help to prevent complications). However, there are circumstances under which a C-section or emergency C-section is necessary.

A nuchal cord is a common but potentially dangerous complication in which the umbilical cord wraps around the fetus’ neck.

A double nuchal cord occurs when the umbilical cord wraps around the baby’s neck two times. This is also relatively common, occurring in about 2-7% of births. It is also possible for a nuchal cord to be wrapped more than twice.

Even when the cord is wrapped multiple times, the baby may still be born healthy. However, babies with multiple nuchal cords may be at a slightly higher risk of complications, such as impaired fetal growth and fetal heart rate abnormalities.

Although rare, the umbilical cord can “strangle” a baby by cutting off oxygen flow to the brain or compressing the carotid artery. The umbilical cord may also become compressed against itself or the baby’s neck, which reduces the flow of oxygenated blood through the umbilical cord. This can also be very dangerous for the baby.

The umbilical cord is responsible for supplying the baby with oxygenated, nutrient-rich blood, and carrying deoxygenated, nutrient-depleted blood back to the placenta. If a nuchal cord interferes with these processes by compressing the umbilical cord or restricting arteries and veins in the baby’s neck, it can lead to birth asphyxia (fetal oxygen deprivation).

The likelihood of birth asphyxia and other birth injuries is influenced by the type of nuchal cord.

Nuchal cords are classified into two main types:

Type A Nuchal Cord: “Unlocked”

When the end of the umbilical cord connected to the placenta crosses over the end connected to the baby. This may be called an “unlocked” nuchal cord. It is likely to spontaneously disentangle when the baby moves in-utero.

Type B Nuchal Cord: “Locked”

When the end of the umbilical cord connected to the placenta crosses under the end connected to the baby. This may be called a “locked” nuchal cord. Locked nuchal cords are less likely to spontaneously disentangle.

When the cord is wrapped around the baby’s neck in a true knot pattern (either type A or type B), the baby can be deprived of oxygen. Sufficient oxygen flow may be interrupted by a true knot when:

1. The cord is compressed, which means the vessels in the cord are blocked, halting the flow of blood to the baby;
2. The cord is so tight it restricts flow in major blood vessels in the baby’s neck;
3. The nuchal cord causes venous blood to become congested, which decreases circulation.

The risk of birth asphyxia depends on how tight or loose a nuchal cord is. If the cord is wound tighter, the risk of asphyxia may be greater. It is important to note that fetal movement can sometimes cause an initially loose nuchal cord to tighten.

Potential complications and birth injuries resulting from a nuchal cord include:

• Hypoxic-ischemic encephalopathy (HIE): HIE is a neonatal brain injury caused by oxygen deprivation and limited blood flow to the baby’s brain at or near the time of birth (i.e. birth asphyxia). Some children with HIE develop disorders such as cerebral palsy, epilepsy, and intellectual/developmental disabilities.
• Intrauterine growth restriction (IUGR): Babies who are abnormally small are at higher risk for brain damage during the birthing process, and must be managed very carefully.
• Meconium in the amniotic fluid: If the baby has their first bowel movement while still in utero, the meconium (stool) can pose a serious threat to their health. Unborn babies swallow amniotic fluid, and if this fluid contains meconium, it can cause a dangerous complication called meconium aspiration syndrome (MAS).
• Fetal heart rate abnormalities: which can increase the risk of operative delivery (requiring use of tools like forceps and vacuum extractors).
• Umbilical artery acidemia:
• Neurodevelopmental abnormalities

A nuchal cord may be more likely to form when:

• The fetus is very active/moves around a lot
• There is a long umbilical cord
• The umbilical cord has insufficient Wharton’s jelly (a gelatinous substance in the umbilical cord)
• The umbilical cord is poorly structured
• The pregnancy involves twins or multiples
• There is too much amniotic fluid surrounding the baby (polyhydramnios)

As the baby’s gestational age increases, so does the likelihood of a nuchal cord.

Usually, pregnant women do not experience any symptoms from a nuchal cord. If the nuchal cord is affecting the baby’s oxygenation, then the baby may begin to show signs of fetal distress such as an abnormal heart rate on the fetal monitor.

Nuchal cords are often identified during an obstetrical ultrasound. To identify a nuchal cord, physicians look at multiple views of the baby’s neck. A nuchal cord is diagnosed when the umbilical cord is seen encircling at least three-quarters of the neck. At term, the sensitivity of ultrasound for detecting nuchal cords is about 70% for gray-scale imaging, and 83% to 97% with color Doppler.

Nuchal cords are very common. They can form at any time, disentangle, and reform. During prenatal testing, a nuchal loop may be recognized with an ultrasound or it may be suspected if the baby is showing signs of distress during a nonstress test or biophysical profile.

During labor and delivery, the fetal heart rate monitor will detect oxygen deprivation in the baby, which manifests as nonreassuring heart tracings. Once these tracings occur, the baby should be promptly delivered, usually by emergency C-section.

Sometimes during delivery, the physician will try to slip the cord over the baby’s head to decrease compression while attempting to deliver the shoulders or body.

The physician may also attempt a technique that involves slipping the cord over the baby’s shoulders, or another maneuver that allows the baby to be born in a somersault. Whatever the approach, the medical team should start making preparations for an emergency C-section in case the baby cannot be quickly and safely delivered via the vaginal route. A nuchal cord is an obstetrical emergency that requires close monitoring of the baby’s heart rate and prompt delivery at the first signs of distress.

Failure to recognize birth asphyxia and nonreassuring heart tracings during prenatal testing or labor and delivery is negligence. Failure to quickly deliver a baby who is experiencing birth asphyxia is also negligence. If this negligence causes permanent injury in the baby, it is medical malpractice. Birth asphyxia often causes neonatal encephalopathy and hypoxic-ischemic encephalopathy, which can cause permanent brain damage and conditions like cerebral palsy.

The main goal in managing a nuchal cord is to prevent cord compression or prolapse during delivery. Preserving an intact nuchal cord will depend on how tightly it is wrapped around the baby’s neck. A loose nuchal cord can usually be slipped over the baby’s head to decrease traction during delivery of the shoulders or body. If this is not possible, the physician may be able to slip the cord over the infant’s shoulders and deliver the baby through the loop. If this is also not possible, the physician may use the somersault technique, which allows the shoulders and body to be born in a somersault, with the cord being unwrapped after the baby is delivered.

In rare cases, other interventions, such as an emergency C-section, must be performed. A delay in performing a necessary C-section can severely exacerbate the detrimental effects of hypoxia and ischemia and can lead to serious brain injury.

Experienced Birth injury Attorneys

If you are seeking the help of an attorney after a nuchal cord was mismanaged, it is very important to choose a lawyer and firm that focus solely on birth injury cases. The attorneys at ABC Law Centers: Birth Injury Lawyers have over a century of joint legal experience handling cases involving dozens of different complications, injuries, and instances of medical malpractice related to obstetrics and neonatal care.

Our attorneys and in-house medical staff determine the causes of our clients’ injuries, the prognoses of birth injured children, and areas of medical negligence. We consult closely with leading medical experts, forensic specialists, and life care-planning professionals to secure our clients’ future care and their parents’ peace of mind, knowing their child will be cared for, no matter what.

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1. UpToDate: Nuchal Cord 
2. “Nuchal Cord: What You Should Know.” 
3. “Nuchal Cord: Causes, Complications, and Management.”