Your First Prenatal Doctor's Visit
What Common Prenatal Tests Will I Be Given? continued...
Your health care provider may listen for the baby's heartbeat with a special instrument called a doppler, which uses ultrasound waves (high frequency sound waves). A doppler usually cannot detect a baby's heartbeat before ten to twelve weeks of pregnancy. The provider may perform an ultrasound (a device using those sound waves to look at pictures of the baby on a screen) during this visit to verify your due date and check the baby's heartbeat.
Your provider will also order several laboratory tests, including:
- Complete Blood Count (CBC): This test screens for blood problems such as anemia (usually due to low levels of iron).
- HIV test: This test is optional, but highly recommended.
- RPR: This test screens for syphilis (a sexually transmitted disease) that can be transmitted to your unborn child. If left untreated, it can cause a dangerous condition called congenital syphilis in the baby that leads to bone and tooth deformity, nerve damage, or brain damage. Also, the baby could be stillborn.
- Rubella: This test screens for immunity (protection) against German measles. Most Americans received vaccinations against rubella as children and are immune. If you aren't you will need to avoid people with the disease (which is rare in the U.S.) as it can have serious consequences for your developing baby. You cannot be vaccinated during pregnancy, but you should be before you leave the hospital after delivery.
- Varicella: This test screens for immunity (protection) against chickenpox. It is usually done only if you don't have a history of the disease, since an initial exposure during pregnancy can be harmful to the developing baby.
- HBsAg: This test screens for hepatitis B (a liver infection) that is transmitted through contaminated needles, or blood, or through saliva, semen, or vaginal fluid. Infected mothers can transmit this disease to their baby during childbirth. You could have this disease and not know it.
- Urinalysis: During this test you will urinate in a cup and the urine will be tested for kidney disease or bladder infections and high levels of sugar that might indicate diabetes. These infections are very common in pregnant women and are easily treated. If left untreated, bladder infections can quickly progress to kidney infections, which can cause problems for the baby or premature labor.
- Type and screen blood test: This test determines your blood type and Rh factor (a protein on the surface of blood cells that causes an immune system response). Everyone is either Rh negative (your blood doesn't contain Rh factor) or Rh positive (your blood contains Rh factor; 85% of us are). Having either is fine, but if the mother's blood is Rh negative and your partner's blood is Rh positive, your baby's blood type may not match yours (it may be Rh positive). This can be a problem during delivery, or even during miscarriage because your body may produce antibodies to protect itself from this "foreign" substance. This phenomenon is called Rh incompatibility and it occurs in about 15% of all pregnancies.
If your partner's blood is Rh+ (and yours is Rh-), you will be given an injection of Rh immune globulin (called Rhogam) during the 28th week of your pregnancy to prevent the development of antibodies that could be harmful to your baby. You will also receive this injection during invasive procedures and if you have any significant bleeding during your pregnancy. Additionally, an injection of Rhogam is given after delivery if your baby has Rh+ blood.
- Genetic Tests: Depending on your ethnic background and medical history, you may also be tested for sickle-cell anemia, Tay-Sachs disease, and thalassemia. Blacks, Jews, French Canadians, and people of Mediterranean descent are most at risk for these illnesses. All of these diseases can be passed onto the baby because of defective genes that the parents may carry (even if they don't have the disease.) Your provider may offer you a test for cystic fibrosis, an inherited disease that can affect breathing and digestion in your baby if you and your partner are carriers. You will also be offered genetic testing for Down syndrome, Trisomy 13 and 18, and spinal defects, which can be done in the first or second trimester of your pregnancy.
The first prenatal visit can be exciting yet stressful. With all the poking and prodding and the uncertainty of test results, it is bound to get any mom-to-be nervous. Keep in mind, all of these tests are routine. If you have any questions about these tests or what the test results may mean, talk to your health care provider.