What is an Umbilical Cord Cyst?

The umbilical cord provides a critical connection between mother and baby during pregnancy. It contains blood vessels that carry food and oxygen from the placenta to the fetus. When the umbilical cord develops a problem, such as prolapse or cord knots, it can cause complications with the pregnancy and child development. An umbilical cord cyst is a rare medical condition (fewer than 1 percent of women get them), and it generally does not pose a threat to the baby.

Diagnosis and Treatment of Umbilical Cord Cysts

An umbilical cord cyst refers to any cystic lesion, or sac of fluid, on the umbilical cord. They have irregular shapes and may exist anywhere along the umbilical cord, generally between blood vessels. A patient can have a single cyst or multiple cysts. Doctors diagnose umbilical cord cysts most often in the first trimester, using ultrasound technology. Cysts found in the first trimester generally do not affect pregnancy. Cysts that persist into the second or third trimester, however, have higher odds of causing complications. There are two types of umbilical cord cysts:

  • True cysts. A true cyst occurs at the placental end of the umbilical cord, close to where it connects to the infant. It contains fluid from the embryo, and is a small remnant of the umbilical vesicle. They most often range in size between four and sixty millimeters. Most true cysts abate on their own.
  • False cysts. A false cyst, or pseudocyst, is more common than a true cyst. They can occur anywhere on the umbilical cord. A false cyst contains fluid from Wharton's jelly, or the cushiony substance between blood vessels. They can grow as large as six centimeters. False cysts may relate to chromosomal anomalies or genetic conditions in the baby.

Second- or third-trimester cysts, combined with other abnormalities, may come with an increased risk of miscarriage or structural anomalies. Umbilical cord cysts in the first trimester generally do not affect pregnancy, fetal growth, or birth. A placental cyst may cause fetal growth retardation if attached close to umbilical cord insertion. A doctor should closely monitor a placental cyst that exists near umbilical cord insertion, to ensure the regular flow of blood through the umbilical cord.

Does an Umbilical Cord Cyst Complicate Pregnancy?

Studies on umbilical cord cysts diagnosed in the first trimester have found no association between poor pregnancy outcomes and this medical condition. One study compared 45 women with umbilical cord cysts to 85 women without, and found no significant difference between the two study groups in terms of birth weight, child development, or pregnancy outcomes. Other research focusing on fetal outcomes with umbilical cord cysts found that women who receive diagnoses in the first trimester have favorable and normal pregnancy outcomes.

In a case involving a second- or third-trimester diagnosis of umbilical cord cysts, pregnancy outcomes are still likely to proceed normally as long as no other anomalies exist. One study compared two women: one with a first-trimester diagnosis of two cysts and the other with a third-trimester diagnosis of an isolated cord cyst. Both women's pregnancies evolved uneventfully and both women gave birth to healthy children with no congenital anomalies. This study concluded that the prognosis of a third-trimester diagnosis of umbilical cord cyst is "usually excellent."

Although a woman with a cyst on her umbilical cord in the first trimester may need additional tests, genetic testing to check for birth defects, and potentially a C-section to prevent cysts from bursting, generally she will not experience any cyst-related pregnancy or birth complications. If your doctor has diagnosed you with a later-trimester umbilical cord cyst plus other anomalies, you may need special care. Talk to your doctor for more information about your specific case.