At 15 weeks
If you have had a CVS or first trimester screening you will have an AFP test (blood) to screen for spina bifida. This can be done between 15 and 22 weeks but we like to have the results back before your 18 week ultrasound. The results will take 3 working days.
At 16 weeks
We strongly recommend you have a screening test called an "AFP tetra" if you have not yet had any genetic testing (CVS, amniocentesis or first trimester screening). The test will screen your baby for Down's Syndrome, Trisomy 18 (another chromosome disorder), neural tube defects and some other less common complications of pregnancy. Like the first trimester screening it is not a diagnostic test so it doesn't tell us whether the baby has any of these conditions or not. It does tell us whether your odds for a particular problem are higher or lower than normal. It doesn't test for all possible problems that a baby could have. This test has caused alarm in patients in the past because they didn't understand how we use the information. If the test suggests your risks are higher (even slightly higher) than the average population we will refer you to the hospital for your ultrasound. You will have a more detailed ultrasound by a specialist who may or may not recommend any further testing such as an amniocentesis. You will always have the option of declining an amniocentesis but we still recommend you see the specialist for the ultrasound. If the results to your "AFP tetra screen" are abnormal you will receive a phone call approximately 3 working days after the test was drawn. At this time we will be able to explain the results so that you will know how significant a risk your baby has (slightly higher risk than average or very likely to have a problem). If your test results are "normal" we will notify you at your next visit. This will mean that the likelihood of a problem like Down Syndrome is very low (but not impossible).