Chorionic Villus Sampling (CVS) is a prenatal test in which a sample of chorionic villi is removed from the placenta for testing. During pregnancy, the placenta provides oxygen and nutrients to the growing baby and removes waste products from the baby's blood.

When Do You Need the Test

Not everyone who is pregnant will need to have chorionic villus sampling. It is usually performed when there is a possibility that the baby may have an abnormal condition. Your doctor may consider chorionic villus sampling if:
1. You are over 35 years of age-women over 35 are at higher risk of having children with chromosomal abnormalities.
2. You or your partner has a genetic disorder.
3. You or your partner has a family history of a genetic disorder.
4. You have had other children with genetic or biochemical disorders.
5. You have had spontaneous abortions.
6. You have had prenatal screening tests with abnormal results.