During pregnancy, certain lab tests are routinely performed on all women. They are done at specific times during the pregnancy to help your doctor identify possible problems with your pregnancy. They will also give clues to how your baby is doing. Other tests that may be done will depend on your medical history, age, family background, ethnic background, or exam results.

Initial Lab Tests – New OB Visit

Pap Smear: Check cervical cells that could lead to cancer.
Cultures: To check for STD’s (sexually transmitted disease) such as Gonorrhea and Chlamydia.
Ultrasound: Used to determine the date of delivery
Blood Work: You will be given an order to go to the lab to have the following blood tests drawn:

  • CBC (complete blood count): This is used to detect anemia as well as any possible infection or clotting problems.
  • Blood Type and Antibody Screen: To check blood type. It can be Rh positive or Rh negative. Problems can arise when the mother’s Rh factor is negative and the baby’s is positive. To prevent these problems, the Rh negative mother will be given a Rhogam injection at 28 weeks.
  • Syphilis: Syphilis is an STD which can be treated. If you have syphilis and are not treated, you can pass it to your baby.
  • Rubella: Your blood will be checked for antibodies against German measles (either from past infection or prior vaccination).
  • Hepatitis B: Hepatitis B is a virus that infects the liver.
  • HIV: HIV is the virus that causes AIDS. Pregnant women are tested even if they don’t have special risk factors. Your doctor will tell you that you are being tested for HIV. If you have HIV, there is a chance that you can pass it to your baby. You can be given medication during pregnancy to reduce this risk.
  • Urinalysis: A urine sample will be collected to test for a urinary tract infection. You will be treated with antibiotics if you have been diagnosed with a urinary tract infection.

At Every Visit

Blood Pressure
Urine Dip: checks for protein and glucose
Fetal Heart Rate
Estimate fetal growth by checking the size of the uterus

At 15-20 Weeks:

Quad Screen. This is a blood test and does not pose a risk to the mother or the fetus. Positive results may indicate the baby may have:
Neural tube defects: problems with the brain or spine such as spina bifida or anencephaly.
Abdominal wall defects: problems with the body of the fetus.
Ultrasound: Used to screen for malformations and appropriate fetal growth.
Genetic defects: physical or mental defects such as Down’s Syndrome.

Please remember that this is a screening test and is not used to diagnose these conditions. If your test is positive, additional testing will be ordered to diagnose any abnormalities. These include ultrasound and amniocentesis.

At 24-28 Weeks:

Glucola or 1 hour glucose tollerance test (GTT): This is a blood test to screen you for gestational diabetes. If this test is positive, you will need the more comprehensive 3 hour glucose tolerance test.

Preparing for the 1 hour glucola:
On the day of your test, do not drink or eat anything for 2 hours before the test.
Plan to be at the lab for at least an hour.
The lab tech will give you a sweet drink called glucola. Exactly one hour after you finish the drink, your blood will be drawn. Do not eat, drink, or chew gum during this hour.
Bring a light snack to eat after the test. This helps to relieve nausea and shakiness that some people feel during the test.

At 28 Weeks (if Rh negative):

Antibody screen and Rhogam injection.

At 35 Weeks:

Group B Strep Culture: A swab is taken from the vagina and rectum to determine if the mother is a carrier of the bacteria. This is a type of bacteria that is normally found in the vagina and/or rectum of some women, and causes no symptoms or problems in adults. However, sometimes it can cause a serious infection in the newborn as he/she passes through the birth canal.

If your test is positive, IV antibiotics will be given to you while in labor to prevent this infection in the newborn. If any problems or complications arise in your pregnancy, additional testing may be ordered, such as:
Ultrasound and/or Biophysical Profile
Non-Stress Test
Blood tests