CVS is usually done between the 10th and 12th weeks of pregnancy. Unlike amniocentesis (another type of prenatal test), CVS does not provide information on neural tube defects, such as spina bifida.

How early can CVS testing be done?

Chorionic Villus Sampling (CVS) is a test for fetal genetic abnormalities that can be performed in early pregnancy and is usually done between 10 and 14 weeks. Under ultrasound guidance, a thin needle is inserted through the abdomen and into the developing placenta. Small samples of placental tissue are collected.

How accurate is a CVS test?

CVS is estimated to be about accurate in 99 cases out of 100. However, it cannot test for every birth defect, and it may not give conclusive results. In about 1 in every 100 cases, the results of CVS cannot be completely certain that the chromosomes in the fetus are normal.