Q. What is an Alphafetoprotein Test?
A. An Alphafetoprotein Test (AFP) is a blood test taken to screen for Neural Tube Defects such as spina bifida, anenecephaly etc. as well as, more recently, to predict the risk of Downs Syndrome.
Q. How is the test preformed?
A. A sample of blood is drawn from the mother for testing. This can be done in the caregiver’s office or at a separate laboratory.
Q. When is the test done?
A. The test has the greatest accuracy between 15 and 17 weeks of gestation. Accurate dating of the pregnancy as well as knowing the number of babies in utero is very important to the accuracy of the test results.
Q. What at the risks of the AFP Test?
A. Other than mild discomfort at the sight of the blood draw, there is no risk from the test itself. However, depending on the results of the test, the AFP test may lead to further tests which do carry risks. Further tests that may be recommended are an Amniocentesis and/or Level II Ultrasound.
Q. Who is the test recommended for?
A. All pregnant women are offered the test, however, most practitioners especially recommend it for women who have a family history of birth defects, are 35 years or older, have used possible harmful drugs during pregnancy, or who have diabetes.
Q. What do the AFP results mean?
A. It is very important to note that the AFP test is a screening test and not a diagnostic test in any way. This means that it is used to note if a woman is at risk of carrying a baby with a potential disorder. It is not used to diagnose any disorder. If the test produces abnormal results, further testing must be done in order to reach a diagnosis.
Q. How accurate is the AFP Test?
A. The benefit of preforming the AFP screening is that 70% to 90% of babies with neural tube defects are discovered. However, about 10% of women who receive the AFP test will show abnormal results. Of these women, 1 in 50 will actually have an affected baby. This means that 49 women will receive false positive results. The downside of receiving false positive results is undue emotional distress.
Q. How can I decide if I should have the AFP test preformed?A. In order to decide whether or not to have the test preformed, you should ask yourself what you would do if the test showed abnormal results. Choosing to have
further testing could help you research potential medical interventions, start
planning for a special needs child, start anticipating lifestyle changes, and find support groups and resources. You might also choose to not have further tests preformed because you would be comfortable with the results no matter the outcome, making a decision about carrying the baby to term is not an option, or you want to avoid any testing that poses any risk of harming the developing baby. Because making a decision about having an AFP test preformed can be a very difficult one, it is important to have all your questions and concerns addressed by your caregiver.