The Quad Screen
This test can be done to determine the possibility of your unborn baby a open neural tube defect, Downs syndrome or Trisomy 18
Remember that no test or procedure is completely accurate when trying to determine if an unborn baby has a genetic defect. These tests measure the possibility of a open neural tube defect, Downs syndrome or Trisomy 18, and both false negative and positive results do happen.
The quad screen is generally done between 16-18 weeks, and results can be had in 2-3 days.
Blood is drawn from the mother, and four specific biochemical markers (alphafeto-protein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol (eC3), and inhibin-A) are measured. These levels, in addition to other information, can determine the possibility of a disorder.
What if you get a positive result?If you do have a positive result, if you choose, you can have an ultrasound and/or amniocentesis or CVS done to determine the possibility of a birth defect. Generally a genetic evaluation will be done prior to further procedures.
Who takes the test?This test is available for all pregnant women. Many people will not take the test because the results can be so shaky, and they will not end a pregnancy because of a chance that their baby will have a disorder. Others will take the test (and further procedures if necessary) to prepare themselves for the possibility, and then others will end the pregnancy.