Labs and Tests During Pregnancy

We will recommend a number of tests during your pregnancy. These tests are done to make sure that you and your baby are doing well.

Many are standard tests, while others may be recommended based on your age or health history.

Blood and Urine Tests

These tests are used to help identify conditions that can affect your health and that of your baby during pregnancy. At your first prenatal visit, we will ask you to have the following tests.

Test Checks For
Complete blood count Anemia (low iron in the blood)
Blood type, Rh, antibodies Your blood type, Rh status, blood group antibodies
Hepatitis antigen Hepatitis B
Serology Syphilis, a sexually transmitted disease
Rubella antibody Immunity to German measles
Urine Infections and kidney disease
HIV antibody Virus that causes AIDS

Depending on your health history, you may also be offered tests to check for:

Rh status

If you have Rh-negative blood and become pregnant with a baby that has Rh-positive blood, your body may have an immune reaction and produce Rh antibodies. This reaction is called Rh sensitization. If Rh antibodies develop, they can, in future pregnancies, attack an Rh-positive baby's blood cells and cause severe anemia in the baby. Rh antibodies don't affect an Rh-negative baby.

If you are Rh-negative, you will have another test for Rh antibodies during your third trimester. A medicine containing antibodies to the Rh factor (RhoGam) will be recommended if you have an amniocentesis, and also around 28 weeks. If you have a miscarriage or a threatened miscarriage, we may recommend RhoGam to prevent Rh sensitization.

Hepatitis B

Hepatitis B can be passed on to your unborn baby. If your blood test shows you have hepatitis B, your baby must be treated at birth and will need a hepatitis B vaccine twice more before 6 months of age. Even if you don't feel sick (not everyone who has the virus gets sick), you can pass the virus on to your unborn baby.

HIV antibody testing

Unless you say no to an HIV test, it will be included in your routine tests. HIV can be spread from an infected mother to her baby during pregnancy, birth, or breastfeeding. If an HIV infection is found during pregnancy, treatment can greatly reduce the chance that the baby will get HIV. An infected mother can also be treated.


Your health care provider may suggest an ultrasound. An ultrasound uses sound waves to create an image of your baby on a monitor. Ultrasound is considered safe for you and your baby.

An ultrasound can be helpful if:

Special Screening Tests

There are special tests that give us more information about your baby. Each pregnancy is different and your health care provider will discuss the test most appropriate for you.

Prenatal risk screening (PRS)

PRS is a blood test that helps predict the risk for certain birth defects. We offer this test to all pregnant women. It is usually done between 15 and 22 weeks. It's your choice whether to have the test. The PRS test includes alpha-fetoprotein (AFP), a test that screens for problems with the development of the brain and spine, and several other tests that together screen for Down syndrome and similar chromosomal problems.

Nuchal translucency screening (NTS)

NTS test uses an ultrasound and blood test to detect genetic disorders and chromosomal abnormalities. If needed, it is usually done between weeks 11 and 14 of pregnancy.

Tests for women at higher risk

If you are at a greater risk of having a baby with chromosome or inherited problems, you may want to consider genetic counseling. You are at greater risk if you are age 35 or older, have had a baby with a chromosomal problem, or have a family history of inherited problems.

If you are at increased risk, you will be offered additional tests which may include:

Other tests

New research is always being done in the area of prenatal screening and testing. At Group Health, we evaluate the latest research on a regular basis. As better tests become available, we will recommend them as part of your prenatal care.

Coverage and Questions

For more information about these tests or your pregnancy, please talk to your health care provider. Coverage for prenatal tests and exams varies by health plan. Certain tests, even if recommended, may not be covered depending on your health plan. Check your benefit booklet or contact Group Health Customer Service for information about your coverage for prenatal testing.

From the "Birth Day News" series.

Clinical review by Jane Dimer, MD
Group Health
Reviewed 03/01/2014