Pregnancy: Lab Tests

Your Lab Tests

prenatal testingLab tests help make sure you are healthy. They also help make sure your baby is growing as it should. You’ll have many lab tests during your pregnancy.

Blood Tests

These help your provider track your health and your baby's health.

Urine Sample

You will be asked to give a urine sample at every visit. This helps make sure you have no infection and that your sugar and protein levels are normal.

Blood Pressure

Your blood pressure will be checked at every visit. High blood pressure during pregnancy can cause problems.

Triple Screen

Some women may have problems with their genes that they could pass on to their babies. If you need one, your provider will offer you a triple screen test. This should be done when you are between 15 and 21 weeks pregnant. This test can check for any problems with your baby's nervous system. It can also tell you if your baby might have Down Syndrome, which causes mental disability.

Glucose Screening

This test checks to see if you are getting diabetes during your pregnancy. It takes about one hour. Usually it will be done around your 26th 28th week of pregnancy. You may need to have it done earlier if members of your family have sugar diabetes. You may also need it done early if you had diabetes during another pregnancy, or if you are overweight.

Hepatitis B

Hepatitis B is an infection of the liver. If you have Hepatitis B, there is a chance that without treatment your baby can get it from you. Your baby can be treated at birth to prevent infection in almost all cases.


This test checks to see if you have HIV, the virus that causes AIDS. Even without symptoms, a woman who has HIV has a 1 in 4 chance of passing it to her baby. This risk can be greatly reduced with treatment. Every pregnant woman should discuss HIV testing with her doctor.

Group B Strep Screening Test

This test is done around your 36th-37th week of pregnancy. Your vagina and rectal areas will be checked for bacteria that could make you or your baby sick. If you have these bacteria, you will be offered antibiotics during labor.


This is a test that uses sound waves to show a picture of your unborn baby. Ultrasound usually is done between week 14 and 16 of your pregnancy in order to:

  • Find out when your baby is due
  • Check to see if you have bleeding or other problems
  • See if your baby is growing normally
  • Find the position of the placenta, which is the part of your womb that gives your baby nourishment

Ultrasound is not an x-ray and does not use radiation. It is not a sure way to find out the sex of an unborn baby, so it is not done for that purpose.