Experience with Neural Tube Defect or AFP Test?!
Question: Experience with Neural Tube Defect or AFP Test!?
I'm 21 weeks pregnant and my doctor called me today with the results of my AFP (alpha fetaprotein) test and told me that they indicated my baby is positive for a neural tube defect (my AFP level was elevated)!. She also told me that there are alot of false positives with this test and the rate of false positives is 1 in 75!. I have no history of neural tube defect in my family, I am 20 years old, my husband is 22 and has no history of this in his family, I was taking prenatal vitamins with folic acid for three months before I conceived, and my doctor did not notice any abnormalities in the baby at my 19 week scan!. Does anyone have a similar experience or any information on neural tube defects or false positives with an AFP blood test in the second trimester that they can share!? I'm really worried and I cannot get in to have a high definition ultrasound until next Wednesday!. Any information would be highly appreciated!Www@Answer-Health@Com
Answers:
It sounds like it hasn't been explained very well!. The test doesn't give you a 'positive' or 'negative' result, it just gives a rough idea of the RISK of a neural tube defect!. The higher the AFP result, the greater the risk of a neural tube defect!. So to quote a 'false positive' rate is meaningless!. Your AFP result must have been higher than most people's, which would put you in a 'high risk' category, This does NOT mean your baby has a neural tube defect, it just means that you are in a group that has been chosen to go on to more detailed testing, like the extra ultrasound they are doing!. The vast majority of people that are in this 'high risk' group will have perfectly healthy babies!. I suggest you ring your doctor and ask what your actual risk value is (it may be called 'adjusted risk' or 'age-adjusted risk')!.
Just as an example, a similar test can be done for the risk of Downs syndrome, and with that test (in the UK), a woman with a 1 in 250 chance of having a baby with Downs syndrome is classed as 'high risk', but actually a 1 in 250 risk is still pretty small!. These tests are just a way of deciding who goes on to have more advanced tests which they can't offer to everyone!.Www@Answer-Health@Com
Just as an example, a similar test can be done for the risk of Downs syndrome, and with that test (in the UK), a woman with a 1 in 250 chance of having a baby with Downs syndrome is classed as 'high risk', but actually a 1 in 250 risk is still pretty small!. These tests are just a way of deciding who goes on to have more advanced tests which they can't offer to everyone!.Www@Answer-Health@Com