Detection of genetic abnormalities.. Amniocentesis. Chorionic villus sampling (CVS). Non-invasive prenatal genetic test

tests genetic abnormalities before birth:

Some tests can detect genetic abnormalities before birth.
Learning about these problems before delivery can help you plan your child's care ahead of time and in some cases even treat the condition while the baby is still in the womb.


With amniocentesis, the doctor inserts a thin needle through the abdominal wall of the pregnant woman into the uterus.

A small sample of amniotic fluid is removed from the sac that surrounds the fetus.
When the fluid is analyzed in the laboratory, it can determine serious genetic or chromosomal disorders, including Down syndrome and spina bifida.

Amniocentesis is usually done during the second trimester (between the fifteenth and twentieth weeks of pregnancy), although it may be done later (usually after the thirty-sixth week) to test whether the baby's lungs are adequately developed for birth.
The results of most amniocentesis tests are available in about two weeks.

Chorionic villus sampling (CVS):

With chorionic villus sampling (CVS), a long, thin needle is inserted through the abdomen to remove a small sample of cells (called chorionic villi) from the placenta.

Or a catheter (a thin plastic tube) is placed into the vagina and then inserted through the cervix to remove cells from the placenta.
This sample is later analyzed in the laboratory. CVS is usually done before amniocentesis during pregnancy, often between weeks ten and twelve. Test results are available within one to two weeks.

Both amniocentesis and CVS are considered accurate and safe procedures for prenatal diagnosis, although they carry a small risk of miscarriage and other complications.
You should discuss both the benefits and risks with your doctor and, in some cases, with a genetic counselor.

Non-invasive prenatal genetic test:

During pregnancy, some of the baby's genetic information (DNA) passes into the mother's bloodstream.
The non-invasive genetic test evaluates this DNA to see if the baby is more prone to certain chromosomal diseases.

A blood sample is taken from the mother (not the baby) usually after 10 weeks of pregnancy. Because this test involves taking a blood sample from the mother, there is no risk of complications or miscarriage.

The results of this test are available in two weeks.
Non-invasive prenatal genetic testing is a diagnostic test which means amniocentesis or chorionic villus sampling may be required to confirm the results.