Tied Up in Knots: Your Baby’s Umbilical Cord
Your baby’s been delivered and you hear the words, “There’s a knot in the umbilical cord.” Any mom would panic. We spend nine months worrying about our baby’s development and health, and when those first cries hit our ears, the last thing we want to hear next is that something could be wrong.
Luckily, knots in the umbilical cord, whether discovered during a routine ultrasound, which is rare, or after baby has arrived, which is normally the case, are not generally problematic. Board Certified Obstetrician and Gynecologist Enrique Infante, M.D., of For Women Only at Elkhart General Hospital, says the reason for umbilical cord knots is not often known, though they may be caused by overly long cords. At times, the umbilical cord can become wrapped around the baby’s neck; if it slips off the neck during delivery and then tightens, an umbilical knot can form. Knots occurring in the umbilical cords of identical twins may be attributed to the cords becoming tangled in-utero.
Clinically, these knots rarely harm the baby and should not be considered dangerous, as long as the knot remains loose, says Infante. However, when the knots tighten and cut off the baby’s oxygen supply, an abnormal heart rate might be seen on the monitor. This can lead to the baby’s distress and, potentially, delivery by C-section. While umbilical knots can be problematic, Infante adds, “There is more concern with other cord anomalies, such as a two vessel cord,” because healthy cords should have two arteries and one vein.
The role of the vein is to carry oxygen and nutrients from the placenta to the baby, while the two arteries eliminate waste from the baby to the placenta. When a fetus has only one artery, known as single umbilical artery, or SUA, problems can occur in the major organs. SUA also indicates a potential chromosomal abnormality, such as trisomy 18, and other birth defects.
Luckily, SUA is not common. March of Dimes states SUA occurs in only 1 percent of single fetus pregnancies and 5 percent of pregnancies with multiples. Testing for birth defects, such as extensive ultrasounds and amniocentesis, may be suggested for a fetus that appears to have only one artery. Additionally, doctors may recommend medical follow-up after the birth.