What is a Pregnancy Blood Test?

Patti Kate
Patti Kate
In some cases an ultrasound is necessary to confirm pregnancy.
In some cases an ultrasound is necessary to confirm pregnancy.

A pregnancy blood test is typically taken when a women experiences early pregnancy symptoms. For this type of test, a sample of blood is drawn from the patient using a needle and syringe. A laboratory technician will prepare a slide of the blood sample and examine it thoroughly under a microscope. The technician will proceed to analyze the sample to check for levels of a hormone called human chorionic gonadotropin (HCG).

Seeing elevated hormone levels in blood tested in a lab is often the definitive proof of pregnancy.
Seeing elevated hormone levels in blood tested in a lab is often the definitive proof of pregnancy.

HCG is present in a human embryo in the earliest stages of development. This pregnancy hormone will not be found in women who aren't pregnant. While urine tests can also show whether HCG is present, this is where the similarity of these methods end. With an at-home urine test, it is recommended to wait until a missed menstrual period—a blood test can be conducted sooner. This is because urine tests cannot detect levels of HCG at the earliest signs of pregnancy.

Quantitative blood tests are used to determine the due date early in pregnancy.
Quantitative blood tests are used to determine the due date early in pregnancy.

A pregnancy blood test, or serum test as it is alternately called, can detect the critical levels of the pregnancy hormone a week or so after a woman has ovulated. A woman who is experiencing symptoms of pregnancy may opt to take one of two specialized blood tests. She can either take the quantitative blood test for an accurate reading of exact measures of HCG or a qualitative blood test. The latter will merely provide conclusive results of whether or not the woman is pregnant.

A blood test is used to measure a woman's production of the HCG hormone during pregnancy.
A blood test is used to measure a woman's production of the HCG hormone during pregnancy.

Many doctors believe that a pregnancy blood test will show more accurate results than tests done at home. Although this may be the case, it is not a foolproof method, and cases can occur that show incorrect results. This is why it is often recommended to take the test more than once, especially if the initial pregnancy blood test was done very early on.

A home pregnancy urine test is cheaper than a blood test, but it will not indicate abnormalities.
A home pregnancy urine test is cheaper than a blood test, but it will not indicate abnormalities.

A pregnancy blood test cannot be done at home. This type of testing needs to be conducted by a medical professional. The laboratory results will typically take several days. These blood tests are more costly than the urine test or in-home pregnancy test.

If a blood test shows abnormally high levels of HCG, it can indicate serious complications or illnesses. This may also indicate the possibility the individual is pregnant with twins. Abnormally low concentrations of HCG in the blood might mean the woman is in danger of a miscarriage or the embryo is experiencing complications.

You might also Like

Readers Also Love

Discuss this Article

Post your comments
Login:
Forgot password?
Register:
    • In some cases an ultrasound is necessary to confirm pregnancy.
      In some cases an ultrasound is necessary to confirm pregnancy.
    • Seeing elevated hormone levels in blood tested in a lab is often the definitive proof of pregnancy.
      Seeing elevated hormone levels in blood tested in a lab is often the definitive proof of pregnancy.
    • Quantitative blood tests are used to determine the due date early in pregnancy.
      Quantitative blood tests are used to determine the due date early in pregnancy.
    • A blood test is used to measure a woman's production of the HCG hormone during pregnancy.
      A blood test is used to measure a woman's production of the HCG hormone during pregnancy.
    • A home pregnancy urine test is cheaper than a blood test, but it will not indicate abnormalities.
      A home pregnancy urine test is cheaper than a blood test, but it will not indicate abnormalities.
    • Abnormally low levels of HCG in the blood may indicate an increased risk of miscarriage.
      Abnormally low levels of HCG in the blood may indicate an increased risk of miscarriage.
    • The pregnancy blood test can detect critical levels of the pregnancy hormone about a week after a woman has ovulated.
      The pregnancy blood test can detect critical levels of the pregnancy hormone about a week after a woman has ovulated.