HIV Test in Pregnancy: Why It’s a Good Idea

The American College of Obstetricians and Gynecologists (ACOG) recommends that all women are tested for HIV during pregnancy or before thinking of getting pregnant. Why? HIV can go undetected for years before it causes symptoms.

A pregnant person with HIV who is not treated can pass the virus to an unborn baby, according to the U.S. Department of Health and Human Services.

With treatment, though, the chances of passing along HIV to a baby are very low. Getting treatment for the viral infection will also help ensure a healthy pregnancy, delivery, and future. The earlier the virus is detected, the better the treatment can work.

HIV is a virus that affects disease-fighting T cells in the immune system. When these cells are not working properly, infections, cancers, and diseases can more easily cause illness.

HIV is passed from person to person through contact with body fluids — blood, breast milk, and semen — and is considered a sexually transmitted infection (STI) because one of the main routes of transmission is through sex without a condom or other barrier method.

Another primary route of transmission is through sharing needles with a person who has HIV. Any other activity that can expose an individual to body fluids containing HIV may also lead to transmission of the virus.

Without treatment, HIV can become stage 3 HIV, or AIDS. However, it may take several months or years for the virus to progress, according to the National Institutes of Health.

That said, there is no cure for HIV. It’s a chronic illness. Treatment focuses on managing the virus and keeping the viral load low. Viral load is just another way of saying how much virus is in the body.

Early detection is key, especially during pregnancy. While having a low viral load may reduce the chances of passing the virus to an unborn child, an infant may contract the virus.

Testing for HIV in pregnancy is the same testing that’s offered to non-pregnant people. The first-line tests screen the blood or saliva for antibodies and antigens — these are proteins in the blood that fight infection.

Antigen/antibody tests

This blood test can detect HIV just 18 to 45 days after initial exposure. It looks for both the HIV antibodies and antigens present in the blood. Both standard and rapid antigen/antibody tests are available. The rapid test uses a finger prick and may not detect the virus for up to 90 days after exposure.

Antibody tests

This blood or saliva test can detect HIV in 23 to 90 days after initial exposure. Many rapid tests are antibody tests, including the at-home self-test. Antibody tests that are performed using blood from a vein detect HIV sooner than those done by finger prick or with saliva.

Nucleic acid tests (NATs)

This blood test can detect HIV in just 10 to 33 days after initial exposure. It looks for the virus in the blood versus just the antibodies. NATs are expensive and are not usually the first test given unless there is a confirmed exposure to HIV or there are symptoms.

The specific test given may depend on:

• the location where testing is performed
• the conditions of exposure (confirmed versus suspected exposure)
• whether an individual is symptomatic
• how long ago exposed to the virus may have occurred

Many doctors and other healthcare professionals will offer routine testing for HIV at the first prenatal visit or as early as possible in pregnancy.

If there are other risk factors for acquiring HIV, such as a recent diagnosis of another STI, a new sexual partner during pregnancy, or a partner who has HIV, a doctor may also recommend being re-tested in the third trimester (around week 36) of pregnancy.

Testing is done via blood test or saliva screening. These methods are relatively noninvasive and offer results in an hour (rapid testing) to a few days. Re-testing may be necessary to confirm the diagnosis if the results are positive (results may take up to 2 weeks). Re-testing may also occur if the results are negative but an individual suspects they have been exposed to the virus.

How much an HIV test will cost has to do with a number of factors, including:

• health insurance coverage
• fees such as copays or deductibles
• where the testing is done

Some clinics offer free testing. Others may provide tests at a reduced rate. Consider calling a doctor or clinic ahead of time to ask about associated costs.

Without insurance, STI test costs may range between $50 to $200 per test estimates Cost Helper. Over-the-counter tests are available for testing at home. For example, the Oraquick at-home HIV test runs around $40 per test.

The HIV Services Locator can help find location-based HIV testing.

False-positive and false-negative HIV test results are both rare. There are more false positives than false negatives. Here is a closer examination of why results may be wrong.

False positive

A false-positive result means that the test was positive, but an individual does not actually have HIV. Technical issues at a testing lab, like a specimen mix-up, mislabeling of a specimen, or human error, may lead to a false positive.

Having another medical condition or participating in an HIV vaccine study may also lead to markers in blood or saliva that give a false-positive result.

Generally, if the results are positive, a doctor will follow up with another test to confirm the positive test results.

False negative

A false-negative result means that the test results are negative, but an individual does have HIV. A false negative may also happen due to lab errors (specimen mix-up, human error, etc.).

While not a “false negative,” an HIV test may be negative if an individual is tested before there is enough of the virus detectable in blood or saliva. If exposure to HIV is suspected, however, it’s important to be tested immediately. If the test is negative, a doctor will recommend re-testing again several weeks later.

The first step after a positive test (usually an antigen/antibody or antibody test) is to confirm the result with follow-up testing. The follow-up testing may be performed on the original sample of blood versus collecting a new sample. If the results are confirmed, working with a doctor is important for creating the treatment plan that’s followed during pregnancy and beyond.

The goals of treatment during pregnancy are to protect a pregnant person’s health and to prevent passing along the virus to the baby.

Treatment involves taking antiretroviral medications (ART) that lower the viral load in the body. A doctor will carefully monitor the HIV viral load.

A high viral load combined with a low number of T cells (CD4 cells) may indicate a higher risk of transmitting HIV to the baby.

What about the baby?

Fortunately, the risk of transmitting HIV to the baby is rare — 1 percent (or less) — with treatment and other safety measures, according to the CDC. The key is taking all medications as prescribed during pregnancy and delivery.

The baby will also need to take ART for the first 4 to 6 weeks of life. In the United States, breastfeeding and pre-chewing food are not recommended because the virus can be transmitted through breast milk and blood.

Read this for more information on HIV treatment options.

HIV can be managed through pregnancy, particularly when it is caught early with STI testing.

A doctor will likely recommend ordering an HIV test at the first prenatal appointment to screen for the virus. There are also other measures that may prevent transmission of the virus during pregnancy, including using condoms or other barrier methods during sex.

Working closely with a doctor can help pregnant people who have HIV to develop an effective treatment plan that includes prescription medications and other precautionary measures to help prevent transmission of the virus to the baby.