A prenatal diagnostic test that detects chromosomal abnormalities in a fetus. It involves the villi (hairlike projections) that compose the chorion (the outer layer of the amniotic fluid. A CVS test can be performed between the 9th and the 12th of pregnancy, providing earlier diagnosis than amniotic fluid studies.
REASONS FOR PROCEDURE
- Mother is over age 35.
- Pregnancy is considered high-risk.
- A blood test (AFP and triple screen) has suggested increased risk for chromosome abnormality.
- Mother has previously had a child with chromosome abnormality, such as Down Syndrome.
DESCRIPTION OF PROCEDURE
- Ultrasound is used to determine the location of the fetus.
- In one technique used, an anesthetic is injected into the abdominal skin and then a long hollow needle is inserted into the abdomen to withdraw the villi.
- The second technique is done through the vagina. A catheter is inserted through the cervix into the uterus, and suction is applied to pull the villi into the catheter which is then removed.
You should experience no follow-up discomfort. Test results should be available within 1-2 weeks.
- In some cases, insufficient villi are obtained and the needle or catheter must be reinserted.
- Slight risk of a miscarriage (1-2%).
- Excessive bleeding (rare).
- Risk of infection.
Bathe or shower as usual.
Medication is usually not necessary following this procedure.
No special diet.