Melissa81230

I am pregnant with twins.  One of the babies has a cyst on its brain.  I was told that in six weeks an ultrasound would be performed to determine if the baby has Trisomy 18.  I am afraid to research this disease and I wanted "gentle" answers to what this disease might be and how it may affect my baby.  Six weeks seems so long to wait for an answer.

[Lisa Kessler, MS, CGC]

It is very difficult when something unexpected comes up during a pregnancy. You did not say how far along you are, but it may be possible to find out more information sooner.

One of the most common fetal cysts found during pregnancy is called a choroid plexus cyst and based on your description I suspect this is what was found. You should confirm this with your healthcare provider. This is most often a normal variant of development found in normal babies, but because it seems to happen more often in babies with trisomy 18, most healthcare providers like to be cautious and do some follow up. In babies that do not have trisomy 18, choroid plexus cysts resolve and have no impact on the developing baby.

I strongly encourage you to meet with a genetic counselor to talk about the ultrasound finding, verify what it is, and learn what your options are for determining if the baby has  trisomy 18.  Trisomy 18 is also called Edward syndrome, and it is caused by the baby having an extra chromosome #18. Typically babies with trisomy18 have many developmental problems.  Prenatal tests are available to confirm or rule out this diagnosis and a genetic counselor can discuss these options with you. You can locate a genetic counselor near you by using the website of the National Society of Genetic Counselors.