Amniocentesis is a prenatal diagnostic test performed after your 15th week of pregnancy. This test will provide you with a definitive (yes or no) assessment about chromosome disorders in the pregnancy, such as Down syndrome. This test can also test for some other genetic disorders for pregnancies considered to be at an increased risk. Testing for infections, lung maturity later in the pregnancy and many other tests can also be completed.
Amniocentesis is also able to detect open neural tube defects, such as spina bifida. This is done by measuring the level of a protein called AFP in the amniotic fluid. This differs from the chorionic villus sampling (CVS), which is the diagnostic testing option available in the first trimester, which is unable to test for open neural tube defects.
Using high-resolution ultrasound for guidance, the physician inserts a needle into the amniotic sac to take out a few teaspoons of amniotic fluid. This sample is then used to complete the testing.
Preliminary results will be available 2 to 3 days after the procedure. Final results will be ready 10 to 14 days following your amniocentesis. Results occasionally take longer. If you do not have your results in fourteen days from the procedure, feel free to contact us. When calling, please be sure to leave phone numbers where you can be reached late in the day.