CVS (Chorionic Villus Sampling)

This is a diagnostic test and is used to determine birth defects such as Down’s syndrome and genetic diseases such as cystic fibrosis, sickle cell disease etc. But it cannot determine neural tube diseases defects (that amniocentesis which is a similar procedure can determine). 

Who?

This is not a routine test and not all women need to take it. Doctors advise it in the following cases:

• Some (not all) women over age 35 because of an increased risk of Down's syndrome and other genetic conditions
• Women who have had a previous child or pregnancy with a birth defect.
• Women who have a family history of a genetic disorder.
• Women who need further evaluation because of the results of first-trimester screening

When?

Between 10-12 weeks

How?

The doctor uses the ultrasound as a guide and inserts a needle through your abdomen or inserts a catheter through your cervix in order to reach the placenta.  Then the doctor takes a sample of cells from the placenta.  These cells are tested in the lab for genetic problems (problems with chromosomes in the cells).

Risks

• This procedure has a very small risk of miscarriage.
• Some women have cramping or spotting for a few hours after the procedure. Call your  doctor if you have heavy bleeding, fever or contractions.