Blood Tests

Reviewed by Dan Brennan, MD on August 09, 2022

Who Gets These Tests?

All women should get certain blood tests when they're pregnant. Blood tests check on your health and help rule out problems.

What the Tests Do

When you first get pregnant, your doctor will take a blood sample. The lab will check for problems that could affect you and your baby. They include rubella, cystic fibrosis, sickle cell anemia, hepatitis B, many sexually transmitted diseases, and others.

Your doctor will also use the sample to check your blood type, Rh factor, glucose, cell counts, and hemoglobin, the protein that carries oxygen throughout your body.

Later on, you will get your blood tested again. These tests can check for gestational diabetes, infections, and gauge your baby's risk of birth defects. (These tests can be done at many points in the pregnancy. Genetic testing is most often done in the first trimester now and is optional.)

How the Tests Are Done

Blood tests are safe for you and your baby. A technician will draw a small amount of blood from your arm.

What to Know About Test Results

If any of your test results are abnormal, your doctor will probably suggest follow-up tests. If there is a problem, treatment or extra monitoring will help keep you and your baby healthy.

How Often the Tests Are Done During Your Pregnancy

You'll get a blood test during your first prenatal visit. In your second trimester, you will get a blood test to check for diabetes and recheck your hemoglobin. If you are Rh negative, your antibodies will be rechecked. You may get other blood tests, depending on your preferences and health.

Other Names for These Tests

Rh factor, First Trimester Screening, Quad Screen, STD Tests, Prenatal labs

Tests Similar to This One

Urine test

Show Sources


ACOG: "Routine Tests in Pregnancy."

Johns Hopkins Manual of Gynecology and Obstetrics, 4th Edition. Lippincott Williams & Williams, 2010.

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