Choroid Plexus Cyst: Causes, Symptoms, and Treatment
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Choroid Plexus Cyst?
An obstetrician-gynecologist (OB-GYN), a doctor who cares for women during pregnancy, usually finds and follows a choroid plexus cyst. A maternal-fetal medicine specialist, a doctor who cares for high-risk pregnancies, may help if other findings show up. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is a choroid plexus cyst?
A choroid plexus cyst is a small pocket of fluid in the choroid plexus of a baby's brain before birth. The choroid plexus is a part of the brain that makes cerebrospinal fluid, the fluid around the brain and spinal cord.
Doctors often see these cysts on an ultrasound in the second trimester of pregnancy. About 1 to 2 out of every 100 babies have one at that time. A cyst can be on one side or on both sides of the brain.
Doctors generally call these cysts pseudocysts, which means they are not true cysts. They are not thought to cause problems in a baby's development. They occur equally in male and female babies.
Symptoms
No proven brain damage or problems with thinking or movement have been linked to the cyst itself. Doctors find the cyst on a prenatal ultrasound.
When a cyst is found, doctors scan the baby closely for other signs of trisomy 18, a chromosome condition. These signs include:
- A strawberry-shaped head.
- Clenched hands.
- Heart problems.
- Slow growth of the baby early in the pregnancy.
- Too much fluid around the baby, called polyhydramnios.
Causes and who gets it
The cause of a choroid plexus cyst is still unknown. Most of these cysts go away before birth. About 90 out of 100 disappear by the third trimester, around week 28. They rarely last after the baby is born.
A cyst is more likely to be linked to trisomy 18 when other findings are present. A link between these cysts and trisomy 18 has been reported.
How doctors diagnose it
Doctors find a choroid plexus cyst on an ultrasound, a scan that uses sound waves to make pictures of the baby. They then do a thorough scan of the baby, called an anomaly scan, to look for other signs. They also review the results of blood screening tests, which check the chance of chromosome problems.
A cyst found alone, with low-risk blood screening, is now considered a normal variant, which means a normal difference and not a disease. It needs no invasive testing.
Doctors consider invasive genetic testing when other findings are present or when blood screening shows a high risk of trisomy 21 or trisomy 18. Invasive testing means taking a sample of amniotic fluid or umbilical cord blood to study the baby's chromosomes.
Treatment
No change in pregnancy care is needed when a cyst is found alone. A follow-up ultrasound is not necessary for a cyst found alone. For a cyst found alone, doctors counsel parents that the outlook is excellent and offer reassurance.
If other findings are present, doctors may offer more testing. The plan then depends on the test results.
When to see a doctor
A cyst seen on a prenatal ultrasound calls for a thorough search for other findings, especially signs of trisomy 18. If you are told that a cyst was seen, ask your pregnancy doctor whether a detailed scan was done and what it showed. A cyst with other findings needs more testing, so ask about next steps.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either can explain what an ultrasound finding means in plain words and help coordinate care with your pregnancy doctor or a specialist.
Common questions
Is a choroid plexus cyst harmful to the baby?
No, a cyst found alone is not considered harmful. Doctors now call it a normal variant, and it carries a good outlook. No proven brain damage has been linked to the cyst itself.
Does a choroid plexus cyst mean my baby has Down syndrome?
No, a choroid plexus cyst does not change the risk of trisomy 21, the chromosome change behind Down syndrome. Doctors should not use the cyst to change that risk.
Will a choroid plexus cyst go away?
Yes, most of these cysts go away before birth. About 90 out of 100 disappear by the third trimester, around week 28.
Is a choroid plexus cyst linked to trisomy 18?
It can be, mostly when other findings are seen on the scan. A cyst found alone, with low-risk blood screening, is considered a normal variant.
Does a choroid plexus cyst need treatment?
No, a cyst found alone needs no change in pregnancy care. A follow-up ultrasound is not necessary for a cyst found alone.
Sources
- National Library of Medicine (PubMed Central) - Prenatal Diagnosis of Choroid Plexus Cyst: What Next?
- National Library of Medicine (PubMed Central) - Choroid Plexus Cysts: Single Nucleotide Polymorphism Array Analysis of Associated Genetic Anomalies and Resulting Obstetrical Outcomes
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.
