What is the inhibin a test?

Mostly for Down syn. Inhibins are proteins made by the ovary - there are 2 types, inhibin a and inhibin b. Inhibin a can be used to look for granulosa cell tumors of the ovary. Inhibin a can also be measured in a pregnant woman's blood to see if the baby may have down's syndrome. Inhibin a is made by the placenta during pregnancy. The test is usually combined with other markers in the mom's blood to give a quad test.