What it detects
CVS is a specific test that is able to tell if your baby has a normal number of chromosomes (46). It can find Down syndrome and other major chromosome abnormalities.
Unlike amniocentesis, it cannot measure the amount of alpha-fetoprotein (AFP) in the amniotic fluid. You will be booked for a blood test at a later date to screen for neural tube defects, such as spina bifida.
Normal results can take up to three weeks. Concerns are usually identified and given to your doctor or midwife within 10 -14 days.
If there is a family history of a known problem, other special tests may be done on the sample. You need to discuss this with your doctor or midwife who will refer you to Medical Genetics so that arrangements for additional tests can be planned in advance of your procedure.
Five in 100 women have a chance of having a baby with a major birth defect that can be found during the first year of life. The most common defects are cleft lip and palate, clubfeet, heart defects and mental retardation. The results from amniocentesis, CVS or fetal blood sampling will indicate whether or not there are chromosome abnormalities or neural tube defects, but will not be able to rule out other abnormalities.