Choroid Plexus Cyst - Chromosome Problems

Chromosome Problems

Genetic counseling is often recommended to provide more information about fetal CPCs, to answer questions and concerns, and to outline available options such as amniocentesis or a blood test from the mother. There is a possible association between ultrasound-detected fetal CPCs and chromosome problems in the baby. Types of chromosome problems that are occasionally seen include Trisomy 18 or Trisomy 21 (Down syndrome).

Generally the risks are very low if there are no other risk factors.

A recent study found that of 106,732 women under the age of 35 that had an isolated CPC identified in a fetal ultrasound, that actually none of the cases had resulted in trisomy 18; the study concluded that "there is no evidence that detection of isolated choroid plexus cyst in women who are <35 years of age increases the risk of trisomy 18". Yet some studies have estimated up to a 1% (1/100) chance of delivering a baby with a chromosome problem when there is a CPC present..

Other factors which may have a bearing on the baby's chances of developing chromosome problems include:

• mother's age at the expected date of delivery
• the results of serum screening; XAFP triple testing or quad screening
• evidence of other "fetal findings" seen at the time of the ultrasound that may suggest a chromosome problem

Many babies with chromosome problems do not show any signs on ultrasound.