Fetal Cystic Hygroma: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Fetal Cystic Hygroma?
A primary care doctor, such as a family doctor or pediatrician, is often the first doctor a family talks to. Fetal cystic hygroma is usually managed by specialists, including a maternal-fetal medicine specialist during pregnancy and, after birth, a pediatric surgeon. A genetic counselor may also be involved.
What is fetal cystic hygroma?
Fetal cystic hygroma is a fluid-filled sac that forms in a baby during pregnancy. It happens when the lymphatic system, the network of vessels that drains fluid from body tissues, does not develop properly. These growths most often appear on the head or neck.
A cystic hygroma is a soft, spongy lump made of sacs filled with clear fluid. If part of the lymphatic system gets blocked or forms wrong during early pregnancy, fluid collects and creates a sac. Some growths are small; others press on nearby body parts.
Symptoms
Before birth, a cystic hygroma usually causes no symptoms for the mother and is most often found on a routine pregnancy ultrasound. After birth, a child may have a soft lump that grows slowly. A large growth can cause trouble with breathing, feeding, or neck movement.
Causes and who gets it
Doctors do not always know why a cystic hygroma forms. It happens when the lymphatic system does not drain fluid the way it should during early development. Some cases are linked to chromosome conditions such as Turner syndrome. In many cases, the cause is never found.
How doctors diagnose it
Most fetal cystic hygromas are found on a routine ultrasound. If a doctor sees one, they may order more tests, such as a detailed ultrasound, an MRI scan, or genetic testing such as amniocentesis.
Treatment
Treatment depends on the size and location of the growth and whether other health problems are present. Some fetal cystic hygromas shrink or go away on their own before birth. Treatment after birth can include surgery or sclerotherapy, a procedure that makes the sac shrink and close.
When to see a doctor
If a pregnancy ultrasound shows a fluid-filled growth on the baby, the mother will usually be referred to a maternal-fetal medicine specialist. After birth, see a doctor if a child has a soft lump on the neck or head. Get medical help quickly if a lump causes trouble breathing or swallowing.
Common questions
Can a fetal cystic hygroma go away on its own?
Yes, some fetal cystic hygromas shrink or disappear before the baby is born. This happens more often with small growths and when chromosome tests are normal. Doctors cannot predict in advance which growths will resolve, so careful monitoring is common.
Does a cystic hygroma mean the baby will have a genetic condition?
Not always. Some babies with a cystic hygroma have normal chromosomes and healthy development. Because there is a link with certain chromosome conditions, doctors often offer genetic testing to learn more.
Can it be treated before birth?
Most fetal cystic hygromas are watched with repeat ultrasounds rather than treated during pregnancy. Treatment, such as surgery or sclerotherapy, is usually done after birth if the growth persists. The care team will discuss the best plan based on the size and location of the growth.
Will my child need surgery?
It depends on the size and location of the growth. Some children need surgery or medicine-based procedures, while others need no treatment at all. Results differ from child to child, and some need more than one procedure.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
