How Common Are Choroid Plexus Cysts?

Choroid plexus cysts are seen during 1% to 3% of all second trimester ultrasound examinations. Choroid plexus cysts are seen at the same rate in fetuses with Down syndrome. However, choroid plexus cysts are seen much more frequently (about 40%) in fetuses with  a condition called  Edwards syndrome (also known as trisomy 18) .

What is Edwards Syndrome?

Edwards syndrome, or Trisomy 18 , is a rare disorder that happens when the baby has  three copies of  chromosome 18 instead of the usual  2 copies. Chromosomes are the structures in the cells of your body that are inherited from each of your parents. Chromosomes hold the instructions for how your body looks and functions. Babies with trisomy 18  have severe mental retardation and usually have many  birth defects, because of the extra chromosome 18. Only 5% to 10 % of infants survive the first year after delivery. Death is usually caused by inability to maintain normal breathing or heart and lung problems

How Can I Tell if My Baby Has Edwards Syndrome (trisomy 18 )?

Other findings that  are often seen in babies with  trisomy 18  include  cleft lip and palate, a small jaw, low set ears, club feet, clenched fists, a single umbilical artery , kidney abnormalities, poor growth, and a high level of amniotic fluid (polyhydramnios) .  More than 90% of babies with trisomy 18  will have  a heart defect.

If the only finding is a choroid plexus cyst  (or cysts) on the ultrasound examination, you are less than 35 years of age, and you have a normal serum screening (quad screen) test, then the chances the baby has trisomy 18  would be very low. 

Amniocentesis may be offered to you to count and examine the chromosomes of the baby. Amniocentesis is a test  in which a fine needle is inserted into the uterus , and a sample of the fluid that surrounds the baby is removed to obtain  the baby's cells that are present the fluid.  The chances of amniocentesis  causing loss of the pregnancy (a miscarriage) due to breaking of your water bag or causing premature labor  is about 1 in 300.

What Happens To The  Choroid Plexus Cysts?

Choroid plexus cysts  generally go away by 28 weeks

Support Groups

Choroid Plexus Cyst Web Site
choroidplexuscyst.org/
A place for expecting parents to exchange information and experiences about choroid plexus cysts in their fetuses

REFERENCES

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