Choroid Plexus Cyst (CPC)

The choroid plexus is the part of the brain that makes the fluid that bathes and nourishes the brain. A CPC is a tiny bubble or pocket of fluid inside the choroid plexus that can be seen on ultrasound. There may be one or multiple CPCs.

Can CPC cause problems for the pregnancy?

A CPC itself does not cause problems and should not be cause for concern. It is not inside the part of the brain that is involved with thinking and learning. CPCs are also not a tumor or type of cancer. They are considered to be normal human variation, as they are found in 1-2% (1 in 50 to 1 in 100) of pregnancies. Most CPCs will go away before delivery; however, even if they do remain, they do not have any effect on the pregnancy. CPCs have also been seen in imaging of healthy individuals who did not have any long-term effects.

Could a CPC mean the baby has other health concerns?

If a CPC is the only finding seen on ultrasound, it is thought to be normal variation of the baby’s development. Rarely, a baby with a CPC may have a chromosome condition such as trisomy 18, or even more rarely, Down syndrome. Trisomy 18 is a genetic condition that causes many birth defects, severe developmental problems, and life-limiting health concerns. Down syndrome is a genetic condition that causes intellectual disabilities and an increased risk for health problems. A baby that has one of these chromosome conditions, particularly trisomy 18, will usually have other ultrasound findings or abnormal blood testing results.

Do I need to consider additional testing?

In most pregnancies, this finding does not significantly increase the chances of a chromosome condition. If you have already had normal blood testing (such as noninvasive prenatal testing, first trimester screening, or quad screening) and a CPC is the only finding on ultrasound, the chance for a chromosome condition is still well under 1%, and additional testing and ultrasounds are not indicated. If you have not had any testing for chromosome conditions in the pregnancy, there are tests available to provide additional information about these risks now that a CPC has been identified on ultrasound.

Where can I get more information?

You can speak with your obstetrician or a genetic counselor if you have additional questions about this ultrasound finding. To schedule a genetic counseling appointment, please call 713-486-9302.