Hormone Inhibin A
There is very little chance of a problem from
having a blood sample taken from a vein.
- You may get a small bruise at the site. You can lower the chance
of bruising by keeping pressure on the site for several minutes.
rare cases, the vein may become swollen after the blood sample is taken. This
problem is called phlebitis. A warm compress can be used several times a day to
- Ongoing bleeding can be a problem for people with
bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning
medicines can make bleeding more likely. If you have bleeding or clotting
problems, or if you take blood-thinning medicine, tell your doctor before your
blood sample is taken.
The inhibin A test is done to measure the
amount of this
hormone in a pregnant woman's blood to see if there is
an increased chance the baby may have
Down syndrome. Inhibin A is made by the
placenta during pregnancy.
result means the level of the hormone inhibin A is low, or negative. An
abnormal result means the level of the hormone inhibin A is high, or positive.1
The level of the hormone must be reviewed with the quad screen blood tests.
All abnormal results will need to be
discussed with your doctor.
What Affects the Test
Things that may affect your test
- If you smoke. This may increase the level of
inhibin A in the blood.
- If you are
obese. This may decrease the level of inhibin A in the
The results of the quad screen, including inhibin A, take
into account a woman's age, race, weight, and whether she has
What To Think About
- The maternal quad screen looks for possible problems in your developing baby (fetus). You can have an ultrasound if
your quad screen is abnormal. If an ultrasound cannot find the cause of the
abnormal results, an amniocentesis may be recommended.
- If abnormal levels of
inhibin A are found, talk with your doctor or a
genetic counselor. The test results can be abnormal,
even when nothing is wrong.
- The level of inhibin A in the blood is often used in a maternal serum quadruple screening test. To learn more, see the topic Triple or Quad Screening for Birth Defects.