HIV and Pregnancy

Preventing Perinatal Transmission of HIV During Pregnancy and Childbirth

Last Reviewed: October 6, 2025

Key Points

  • HIV testing should be performed before pregnancy or as early as possible during each pregnancy to detect HIV and start treatment (antiretroviral therapy) as early as possible.
  • When taken as prescribed throughout pregnancy, childbirth, and breastfeeding, antiretroviral therapy reduces the likelihood of perinatal transmission of HIV to less than 1 percent.
  • When HIV medicines are taken consistently during pregnancy, vaginal deliveries are generally safe. If HIV is untreated or viral loads exceed 1,000 copies/mL during pregnancy, a cesarean delivery can help reduce the likelihood of perinatal transmission.
  • Babies exposed to HIV during birth should receive HIV medicines within six hours of delivery to reduce the likelihood of perinatal transmission.

 

Is HIV testing recommended during pregnancy?

The Centers for Disease Control and Prevention (CDC) recommends HIV testing during each pregnancy at the first prenatal visit. Additional HIV testing is recommended in the third trimester for those who may have a higher likelihood of getting HIV. If no HIV testing occurred during pregnancy, testing is recommended at the time of delivery. The earlier HIV is detected, the sooner HIV medicines can be started.

During pregnancy or when trying to get pregnant, sexual partners should also get tested for HIV and other sexually transmitted infections (STIs), if possible. STIs can increase the amount of HIV in the body (viral load) and increase the likelihood of HIV transmission. If a partner has HIV, they should take HIV medicine as prescribed to stay healthy and prevent transmission.

What is perinatal transmission of HIV? 

Perinatal transmission of HIV occurs when HIV passes from the mother to a fetus or baby during pregnancy, childbirth (also called labor and delivery), or breastfeeding (through breast milk).

The use of HIV medicines and other strategies has helped reduce the rate of perinatal transmission of HIV to 1 percent or less in the United States and Europe. Both early HIV testing and consistent treatment (when applicable) are important to prevent perinatal transmission of HIV.

How do HIV medicines prevent perinatal transmission of HIV?

Antiretroviral therapy (ART) is the use of HIV medicines to treat HIV. When taken as prescribed, ART prevents HIV from multiplying and reduces viral load to undetectable levels. An undetectable viral load means the level of HIV in the blood is too low to be detected by a viral load test.

Having an undetectable viral load during pregnancy and throughout breastfeeding lowers the risk of perinatal transmission of HIV to less than 1 percent.

Should HIV medicines be started during pregnancy?

During pregnancy, HIV medicines should be used to reduce the likelihood of perinatal transmission. The earlier HIV medicines are started, the more effective they are at preventing perinatal HIV transmission. For women planning to conceive, HIV medicines should be started before pregnancy occurs, if possible.

Whether HIV medicines are started before or during pregnancy, they should be continued throughout pregnancy, childbirth, and breastfeeding (if applicable) to prevent perinatal transmission and to promote personal health.

In addition, babies exposed to HIV during pregnancy or at delivery should receive HIV medicines to reduce the risk of perinatal transmission. Several factors determine what medicines babies receive and for how long. See the Preventing Perinatal Transmission of HIV After Birth fact sheet for more details.

Are HIV medicines safe to use during pregnancy?

HIV medicines are generally safe to use during pregnancy. Data from the Antiretroviral Pregnancy Registry continue to show that HIV medicines do not increase the risk of birth defects. However, some HIV medicines may not be recommended for use during pregnancy due to a lack of data.

Health care providers discuss the benefits and risks of specific HIV medicines to help decide which medicines to use during pregnancy or while trying to conceive. If pregnancy occurs while already taking HIV medicines, those medicines should be continued unless a health care provider advises otherwise.

Are there other ways to prevent perinatal transmission of HIV?

A cesarean delivery (sometimes called a C-section) is recommended in the 38th week of pregnancy to reduce the risk of perinatal transmission when HIV viral load is unknown or high (greater than 1,000 copies/mL).

In contrast, when HIV viral load is lower than (or equal to) 1,000 copies/mL near delivery, a cesarean delivery is not recommended solely to prevent perinatal HIV transmission.

After childbirth, choosing alternatives to breastfeeding can eliminate the ongoing risk of perinatal transmission. See the Preventing Perinatal Transmission of HIV After Birth fact sheet for more information on infant feeding.

Where can I learn more about preventing perinatal transmission of HIV?

Read the following HIVinfo fact sheets:

This fact sheet is based on information from the following sources:

From the HIV Clinical Practice Guidelines at Clinicalinfo.HIV.gov:

Also see the HIV Source collection of HIV links and resources.