Birth Defects Testing - Reference Triple or quadruple (quad)
blood tests. These tests check the amounts of three or four
substances in a pregnant woman's blood. The triple screen checks
the levels of Reference alpha-fetoprotein protein (AFP),
Reference beta human chorionic gonadotropin (beta-hCG), and a
type of Reference estrogen (estriol, or uE3). The quad screen
checks those three substances, plus the level of the Reference
hormone inhibin A. The doctor looks at these test results—along
with your age and other factors—to find out the chance that your
baby may have certain problems. Second-trimester tests can be
done between 15 and 20 weeks of pregnancy. The triple and quad
blood tests may be called the expanded AFP test, the AFP plus
test, or the multiple marker screening test. Either of these
tests may be done as the second part of the Reference integrated
screening test Opens New Window. - Reference Ultrasound. This
test allows your doctor to see an image of your developing baby.
It is often done at 18 to