Some tests can detect genetic abnormalities before childbirth. Knowing about these problems before childbirth can help you plan your child’s health care in advance. In some cases even treat the disorder while the baby is in the womb.

Test that can be used to detect genetic abnormalities

Amniocentesis : During the procedure, the doctor inserts a thin needle through the pregnant woman’s abdominal wall into the uterus. A sample of amniotic fluid is taken and analyzed in the lab. It checks for serious genetic disorders such as Down syndrome. This procedure is usually done in the second trimester  (between the fifteenth and twentieth weeks of pregnancy), although it may be done later (typically after the thirty-sixth week) to test whether the baby’s lungs are developed enough for birth. The results are usually available within about 2 weeks.

Chorionic villus sampling CVS  : A long slender needle is inserted into the abdomen to remove a sample of chorionic cells known as chorionic villi from the placenta. The sample is  then analyzed in the lab. CVS is usually performed earlier in pregnancy than an amniocentesis , usually between 10th and 12th week of pregnancy. The results are available in 1 to 2 weeks .

Both CVS and amniocentesis are considered accurate and safe procedures for prenatal diagnosis. They however pose a small risk of miscarriage and other complications. You should discuss the benefits and risks with your doctor and a genetic counsellor.

Non-invasive prenatal testing NIPT : During pregnancy, some of the baby’s genetic information  crosses into the mother’s bloodstream. NIPT analyzes this DNA to check if the baby has a higher chance of  having certain chromosomal disorders. A blood sample is taken from the mother after the 10th week of pregnancy.  There is no risk of a miscarriage or other complications because it only involves drawing blood from the mother. The results are available in 1 to 2 weeks. An amniocentesis or CVS may be offered to confirm results.