Knowledge | Nuchal Cord: A Common Obstetric Finding That Rarely Causes Harm
What Is a Nuchal Cord?
A nuchal cord occurs when the fetal umbilical cord wraps around the neck one or more times in the uterus. The umbilical cord is a flexible, tube-like structure that delivers oxygen and nutrients to the fetus and removes waste. It contains two arteries and one vein, protected by a substance called Wharton's jelly.
Nuchal cords are classified into two types:
Type A nuchal cord (unlocked): the cord can move freely and usually unwraps naturally.
Type B nuchal cord (locked): the cord is wrapped more tightly and is unlikely to unwrap naturally.
Causes of Nuchal Cord
Fetal movement in the uterus is the main cause of a nuchal cord. Other possible factors include:
More amniotic fluid: provides more room for fetal movement;
A longer umbilical cord: more likely to wrap around the fetal body.
Research shows that the likelihood of a nuchal cord increases as pregnancy progresses. About 6% of fetuses have a nuchal cord at 20 weeks, rising to 29% at 42 weeks.
Nuchal cords are also more common in male fetuses, but maternal age and ethnicity do not significantly affect their incidence.
Risks and Potential Complications
Although a nuchal cord usually does not harm the fetus, it may be associated with the following complications in some cases:
Umbilical cord knot;
Delayed fetal growth;
Reduced amniotic fluid;
Reduced fetal movement;
Prolonged pregnancy;
Intrauterine growth restriction (IUGR);
Anemia or low blood volume;
Metabolic acidosis;
Stillbirth.
If the cord is very tight, it may cause tight nuchal cord syndrome (tCAN), with findings such as blood spots on the neck, face, and eyes; abrasions on the neck; and purplish-red facial skin.
How Is a Nuchal Cord Diagnosed?
A nuchal cord can sometimes be detected on prenatal ultrasound, but most are diagnosed during delivery. Because it is common, clinicians routinely check for a cord around the neck during delivery.
How Is a Nuchal Cord Managed?
There is currently no prenatal treatment for a nuchal cord. If diagnosed before delivery, the doctor may monitor the fetal heart rate more closely during labor to ensure fetal well-being.
During delivery, most nuchal cords are loose and can easily be slipped over the baby's head. If the cord is too tight, the doctor may clamp and cut it before the baby is fully delivered to avoid damage to the placenta.
If the nuchal cord causes a drop in fetal heart rate, the doctor may ask the patient to change position to reduce cord compression and may provide supplemental oxygen or intravenous fluids. If the heart rate does not improve, medication may be used to slow uterine contractions, or a cesarean delivery may be required.
Should You Be Concerned About a Nuchal Cord?
A nuchal cord is common and usually has no long-term effect on fetal health. Research indicates that it does not significantly increase the risk of a low Apgar score, developmental problems, or stillbirth. Pregnant women with concerns should discuss them with their doctor before delivery for professional guidance and support.
Knowledge | Nuchal Cord: A Common Obstetric Finding That Rarely Causes Harm
Knowledge | Nuchal Cord: A Common Obstetric Finding That Rarely Causes Harm
What Is a Nuchal Cord?
A nuchal cord occurs when the fetal umbilical cord wraps around the neck one or more times in the uterus. The umbilical cord is a flexible, tube-like structure that delivers oxygen and nutrients to the fetus and removes waste. It contains two arteries and one vein, protected by a substance called Wharton's jelly.
Nuchal cords are classified into two types:
Type A nuchal cord (unlocked): the cord can move freely and usually unwraps naturally.
Type B nuchal cord (locked): the cord is wrapped more tightly and is unlikely to unwrap naturally.
Causes of Nuchal Cord
Fetal movement in the uterus is the main cause of a nuchal cord. Other possible factors include:
More amniotic fluid: provides more room for fetal movement;
A longer umbilical cord: more likely to wrap around the fetal body.
Research shows that the likelihood of a nuchal cord increases as pregnancy progresses. About 6% of fetuses have a nuchal cord at 20 weeks, rising to 29% at 42 weeks.
Nuchal cords are also more common in male fetuses, but maternal age and ethnicity do not significantly affect their incidence.
Risks and Potential Complications
Although a nuchal cord usually does not harm the fetus, it may be associated with the following complications in some cases:
Umbilical cord knot;
Delayed fetal growth;
Reduced amniotic fluid;
Reduced fetal movement;
Prolonged pregnancy;
Intrauterine growth restriction (IUGR);
Anemia or low blood volume;
Metabolic acidosis;
Stillbirth.
If the cord is very tight, it may cause tight nuchal cord syndrome (tCAN), with findings such as blood spots on the neck, face, and eyes; abrasions on the neck; and purplish-red facial skin.
How Is a Nuchal Cord Diagnosed?
A nuchal cord can sometimes be detected on prenatal ultrasound, but most are diagnosed during delivery. Because it is common, clinicians routinely check for a cord around the neck during delivery.
How Is a Nuchal Cord Managed?
There is currently no prenatal treatment for a nuchal cord. If diagnosed before delivery, the doctor may monitor the fetal heart rate more closely during labor to ensure fetal well-being.
During delivery, most nuchal cords are loose and can easily be slipped over the baby's head. If the cord is too tight, the doctor may clamp and cut it before the baby is fully delivered to avoid damage to the placenta.
If the nuchal cord causes a drop in fetal heart rate, the doctor may ask the patient to change position to reduce cord compression and may provide supplemental oxygen or intravenous fluids. If the heart rate does not improve, medication may be used to slow uterine contractions, or a cesarean delivery may be required.
Should You Be Concerned About a Nuchal Cord?
A nuchal cord is common and usually has no long-term effect on fetal health. Research indicates that it does not significantly increase the risk of a low Apgar score, developmental problems, or stillbirth. Pregnant women with concerns should discuss them with their doctor before delivery for professional guidance and support.
Source:
Collected online