Blood tests done for pregnancy are considered more accurate than a urine test, but not necessarily any more sensitive. Pregnancy blood tests measure the levels of a hormone called human chorionic gonadotropin (hCG) to determine whether or not a woman is pregnant. If a woman is at least ten days pregnant then the test can be done.
Types of Blood Tests Done
There are actually two types of blood tests done for pregnancy. The first test is called a quantitative blood test. This test will measure the exact amount of hCG in a woman’s blood. The second test is called a qualitative hCG blood test. This test will only tell a woman whether she is pregnant or not.
Accuracy of These Blood Tests
These blood tests can be conducted sooner than home pregnancy tests. They can usually tell whether or not a woman is pregnant approximately seven to twelve days from the date of conception. Only a blood test can provide the most accurate results.
Using The Blood to Test For Pregnancy
When woman is experiencing a healthy pregnancy, the blood tests done for pregnancy will show normal hCG levels throughout the time she is pregnant. The levels of hCG are expected to increase throughout the first trimester of pregnancy and then they will begin to decrease. If the levels of hCG do not increase during the first trimester it could indicate some trouble with the pregnancy.
Getting a Blood Test
Blood tests done for pregnancy will be collected by a healthcare professional. They will tie a tourniquet around the selected arm about the level where the blood draw will be and then use a needle in order to draw blood from a vein in the arm. Some women may need to have this test done several times throughout their pregnancy if the pregnant woman is at risk for pregnancy complications.
Preparing For a Blood Test
There really is not anything a woman needs to do to prepare for a blood test done for pregnancy. If she will be getting a urine test first then she should avoid drinking too many liquids. She should also avoid certain medications such as diuretics and certain antihistamines.