Standard Tests during Your First Prenatal Appointment - dummies

Standard Tests during Your First Prenatal Appointment

By Joanne Stone, Keith Eddleman, Mary Duenwald

Brace yourself: You’re probably going to be stuck with a needle and have to pee in a cup during your first prenatal visit. Here’s a look at the standard procedures, including blood and urine tests.

Blood tests

On your first prenatal visit, your practitioner will draw your blood for a bunch of standard tests to check your general health, as well as to make sure you are immune to certain infections. The following tests are routine:

  • A standard test for blood type, Rh factor, and antibody status.

  • Complete blood count (CBC). This test checks for anemia, which refers to a low blood count. It also checks your platelet count (a component of blood important in clotting).

  • VDRL or RPR. These tests check for syphilis, a sexually transmitted disease. They’re very accurate, but sometimes they produce a false positive result if the patient has other conditions, such as lupus or antiphospholipid antibody syndrome.

  • Hepatitis B. This test checks for evidence of the hepatitis viruses.

  • Rubella. Your practitioner also checks for immunity to rubella (also called German measles). Most women have been vaccinated against rubella or, because they have had the illness in the past, their blood carries antibodies, which is why the risk of contracting German measles during pregnancy is so rare.

  • HIV. Some states require that healthcare providers routinely ask whether you want to be checked for HIV, the virus that causes AIDS. Because medication is available to reduce the risk of transmission to the baby, as well as to slow disease progression in the mother, being aware of your HIV status is very important. A doctor can usually perform this test at the same time as the other prenatal blood tests.

Doctors sometimes need to perform other tests during your first prenatal visit. These additional tests include the following:

  • Glucose screen. You usually get this test around 24 to 28 weeks, but your doctor may administer it in the first trimester if you’re at a high risk of developing gestational diabetes.

  • Varicella. Your doctor may conduct this test to check for immunity to varicella (chickenpox).

  • Toxoplasmosis. Sometimes a doctor administers a test in order to check for immunity to toxoplasmosis, which is a type of parasitic infection. In the United States, testing for toxoplasmosis isn’t considered routine unless you’re at a higher risk for contracting it.

  • Cytomegalovirus (CMV). Testing for CMV, a common childhood infection, isn’t routine during pregnancy. However, if you have a lot of contact with school-age children who may have the infection, your practitioner may suggest you have this test. As with toxoplasmosis, the blood test looks for evidence of past or recent infection.

  • Vitamin D. Vitamin D deficiency is more common in pregnancy than previously thought. In fact, it is quite common in certain high-risk groups, including vegetarians, women who have limited sun exposure, and ethnic minorities. Babies born to vitamin D-deficient moms are also at risk of vitamin D deficiency.

  • Lead screening. Prenatal lead exposure has been linked to a variety of adverse outcomes for mom and baby. Recently, the Centers for Disease Control and Prevention (CDC) and the American College of Obstetricians and Gynecologists (ACOG) have addressed the issue of screening for elevated lead levels in maternal blood.

Take a quick trip to the bathroom: Urine tests

Each time you visit your practitioner during your pregnancy, including the first prenatal visit, you’re asked to give a sample of urine. Your practitioner uses the urine sample to check for the presence of glucose (for a possible sign of diabetes) and protein (for evidence of preeclampsia).

Sneak the first look at your baby: Ultrasound

An ultrasound uses sound waves to create a picture of the uterus and the baby inside it. Ultrasound examinations don’t involve radiation, and the procedure is safe for both you and your baby. Your practitioner may suggest that you undergo a first-trimester ultrasound exam.

Often, this ultrasound is performed transvaginally, which means that a special ultrasound probe is inserted into the vagina. The advantage to this technique is that the probe, or transducer, is closer to the fetus, so a much clearer view is attained than with a standard transabdominal ultrasound examination.

Some women worry that a probe inserted into the vagina could harm the baby. Although understandable, you don’t need to worry. The probe is completely safe.

The following are evaluated during a first-trimester ultrasound exam:

  • The accuracy of your due date

  • Fetal viability

  • Fetal abnormalities

  • Fetal number

  • The condition of your ovaries

  • The presence of fibroid tumors

  • Location of the pregnancy: Occasionally, the pregnancy may be located outside the uterus, which is called an ectopic pregnancy.