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HIV Prevention

Preventing Mother-to-Child Transmission of HIV

  • Key Points

    • Mother-to-child transmission of HIV is the spread of HIV from a woman living with HIV to her child during pregnancy, childbirth (also called labor and delivery), or breastfeeding (through breast milk). Mother-to-child transmission of HIV is also called perinatal transmission of HIV.
    • The use of HIV medicines and other strategies have helped to lower the rate of mother-to-child transmission of HIV to 1% or less in the United States and Europe. (HIV medicines are called antiretrovirals.)
    • Pregnant women with HIV take HIV medicines during pregnancy and childbirth to prevent mother-to-child transmission of HIV. A scheduled cesarean delivery (sometimes called a C-section) can reduce the risk of mother-to-child transmission of HIV in women who have a high viral load (more than 1,000 copies/mL) or an unknown viral load near the time of delivery.
    • After birth, babies born to women with HIV receive HIV medicine to reduce the risk of mother-to-child transmission of HIV. Several factors determine what HIV medicine they receive and how long they receive the medicine.
    • Despite ongoing use of HIV medicines after childbirth, a woman with HIV can still pass HIV to her baby while breastfeeding. In the United States, infant formula is a safe and readily available alternative to breast milk. For these reasons, women with HIV who live in the United States should not breastfeed their babies.
  • What is mother-to-child transmission of HIV?

    Mother-to-child transmission of HIV is the spread of HIV from a woman living with HIV to her child during pregnancy, childbirth (also called labor and delivery), or breastfeeding (through breast milk). Mother-to-child transmission of HIV is also called perinatal transmission of HIV.

    The use of HIV medicines and other strategies have helped to lower the rate of mother-to-child transmission of HIV to 1% or less in the United States and Europe. (HIV medicines are called antiretrovirals.) 

  • Is HIV testing recommended for pregnant women?

    The Centers for Disease Control and Prevention (CDC) recommends that all women get tested for HIV before they become pregnant or as early as possible during each pregnancy. The earlier HIV is detected, the sooner HIV medicines can be started.

    Pregnant women with HIV take HIV medicines to reduce the risk of mother-to-child transmission of HIV. When started early, HIV medicines are more effective at preventing mother-to-child transmission of HIV. The HIV medicines will also protect the women’s health.

  • How do HIV medicines prevent mother-to-child transmission of HIV?

    HIV medicines prevent HIV from multiplying, which reduces the amount of HIV in the body (called the undetectable viral load is when the level of HIV in the blood is too low to be detected by a viral load test. The risk of mother-to-child transmission of HIV during pregnancy and childbirth is lowest when a woman with HIV has an undetectable viral load. Maintaining an undetectable viral load also helps keep the mother-to-be healthy.

    Some HIV medicines used during pregnancy pass from the pregnant woman to her unborn baby across the cesarean delivery (sometimes called a C-section) can reduce the risk of mother-to-child transmission of HIV in women who have a high viral load (more than 1,000 copies/mL) or an unknown viral load near the time of delivery.

    After birth, babies born to women with HIV receive HIV medicine to reduce the risk of mother-to-child transmission of HIV. Several factors determine what HIV medicine they receive and how long they receive the medicine.
  • Are HIV medicines safe to use during pregnancy?

    Most HIV medicines are safe to use during pregnancy. In general, HIV medicines don't increase the risk of birth defects. Health care providers discuss the benefits and risks of specific HIV medicines when helping women with HIV decide which HIV medicines to use during pregnancy or while they are trying to conceive.

  • Are there other ways to prevent mother-to-child transmission of HIV?

    Despite ongoing use of HIV medicines after childbirth, a woman with HIV can still pass HIV to her baby while breastfeeding. In the United States, infant formula is a safe and readily available alternative to breast milk. For these reasons, women with HIV who live in the United States should not breastfeed their babies.

    Additionally, babies should not eat food that was pre-chewed by a person with HIV.

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

    From CDC:

    From the Department of Health and Human Services:

The Basics of HIV Prevention

  • Key Points

    • People can get or transmit HIV only through specific activities, such as through sex or injection drug use. HIV can be transmitted only in certain body fluids from a person who has HIV. These fluids are blood, semen, pre-seminal fluids, rectal fluids, vaginal fluids, and breast milk.
    • To reduce your risk of HIV, use condoms correctly every time you have sex. Don’t inject drugs. If you do, use only sterile injection equipment and water and never share your equipment with others.
    • If you don’t have HIV but are at risk of getting HIV, talk to your health care provider about pre-exposure prophylaxis (PrEP). PrEP involves taking a specific HIV medicine every day to reduce the risk of getting HIV through sex or injection drug use.
  • How is HIV transmitted?

    The person-to-person spread of HIV is called HIV transmission. People can get or transmit HIV only through specific activities, such as through sex or injection drug use. HIV can be transmitted only in certain body fluids from a person who has HIV:
    • Blood
    • Semen
    • Pre-seminal fluids
    • Rectal fluids
    • Vaginal fluids
    • Breast milk

    HIV transmission is only possible if these fluids come in contact with a mucous membrane or damaged tissue or are directly injected into the bloodstream (from a needle or syringe). Mucous membranes are found inside the rectum, the vagina, the opening of the penis, and the mouth.

    In the United States, HIV is spread mainly by:

    • Having anal or vaginal sex with someone who has HIV without using a condom or taking medicines to prevent or treat HIV
    • Sharing injection drug equipment (works), such as needles, with someone who has HIV

    HIV can also spread from a woman with HIV to her child during pregnancy, childbirth (also called labor and delivery), or breastfeeding. This is called mother-to-child transmission of HIV.

    You can't get HIV from casual contact with a person who has HIV, such as a handshake, a hug, or a closed-mouth kiss. And you can't get HIV from contact with objects such as toilet seats, doorknobs, or dishes used by a person who has HIV. Use the ClinicalInfo You Can Safely Share…With Someone With HIV infographic to spread this message.

  • How can I reduce my risk of getting HIV?

    Anyone can get HIV, but you can take steps to protect yourself from HIV.
    • Get tested for HIV. Talk to your partner about HIV testing and get tested before you have sex. Use this testing locator from the Centers for Disease Control and Prevention (CDC) to find an HIV testing location near you.
    • Choose less risky sexual behaviors. HIV is mainly spread by having anal or vaginal sex without a condom or without taking medicines to prevent or treat HIV.
    • Use condoms every time you have sex. Read this fact sheet from CDC on how to use condoms correctly.
    • Limit your number of sexual partners. The more partners you have, the more likely you are to have a partner with poorly controlled HIV or to have a partner with a sexually transmitted disease (STD). Both of these factors can increase the risk of HIV transmission.
    • Get tested and treated for STDs. Insist that your partners get tested and treated, too. Having an STD can increase your risk of getting HIV or spreading it to others.
    • Talk to your health care provider about pre-exposure prophylaxis (PrEP). PrEP is an HIV prevention option for people who don't have HIV but who are at risk of getting HIV. PrEP involves taking a specific HIV medicine every day to reduce the risk of getting HIV through sex or injection drug use. For more information, read the ClinicalInfo fact sheet on Pre-Exposure Prophylaxis (PrEP).
    • Don't inject drugs. But if you do, use only sterile drug injection equipment and water and never share your equipment with others.
  • I am HIV positive. How can I prevent passing HIV to others?

    Take HIV medicines daily. Treatment with HIV medicines (called antiretroviral therapy or ART) helps people with HIV live longer, healthier lives. ART can't cure HIV, but it can reduce the amount of HIV in the body (called the viral load). One of the main goals of ART is to reduce a person's viral load to an undetectable level. An undetectable viral load means that the level of HIV in the blood is too low to be detected by a viral load test. People with HIV who maintain an undetectable viral load have effectively no risk of transmitting HIV to an HIV-negative partner through sex.

    Here are some other steps you can take to prevent HIV transmission:

    • Use condoms correctly every time you have sex.
    • Talk to your partner about taking PrEP.
    • If you inject drugs, don't share your needles, syringes, or other drug equipment with your partner.
  • Are HIV medicines used at other times to prevent HIV transmission?

    Yes, HIV medicines are also used for post-exposure prophylaxis (PEP) and to prevent mother-to-child transmission of HIV.

    • Post-exposure prophylaxis (PEP) 
      PEP means taking HIV medicines within 72 hours after a possible exposure to HIV to prevent HIV infection. PEP should be used only in emergency situations. It is not meant for regular use by people who may be exposed to HIV frequently. For more information, read the ClinicalInfo fact sheet on Post-Exposure Prophylaxis (PEP).   
    • Prevention of mother-to-child transmission of HIV 
      Pregnant women with HIV take HIV medicines for their own health and to prevent mother-to-child transmission of HIV. After birth, babies born to women with HIV receive HIV medicine to protect them from infection with any HIV that may have passed from mother to child during childbirth. For more information, read the ClinicalInfo fact sheet on Preventing Mother-to-Child Transmission of HIV.
  • This fact sheet is based on information from the following sources:

    From CDC:

    From the Department of Health and Human Services:

Preventing Mother-to-Child Transmission of HIV

  • Key Points

    • Mother-to-child transmission of HIV is the spread of HIV from a woman living with HIV to her child during pregnancy, childbirth (also called labor and delivery), or breastfeeding (through breast milk). Mother-to-child transmission of HIV is also called perinatal transmission of HIV.
    • The use of HIV medicines and other strategies have helped to lower the rate of mother-to-child transmission of HIV to 1% or less in the United States and Europe. (HIV medicines are called antiretrovirals.)
    • Pregnant women with HIV take HIV medicines during pregnancy and childbirth to prevent mother-to-child transmission of HIV. A scheduled cesarean delivery (sometimes called a C-section) can reduce the risk of mother-to-child transmission of HIV in women who have a high viral load (more than 1,000 copies/mL) or an unknown viral load near the time of delivery.
    • After birth, babies born to women with HIV receive HIV medicine to reduce the risk of mother-to-child transmission of HIV. Several factors determine what HIV medicine they receive and how long they receive the medicine.
    • Despite ongoing use of HIV medicines after childbirth, a woman with HIV can still pass HIV to her baby while breastfeeding. In the United States, infant formula is a safe and readily available alternative to breast milk. For these reasons, women with HIV who live in the United States should not breastfeed their babies.
  • What is mother-to-child transmission of HIV?

    Mother-to-child transmission of HIV is the spread of HIV from a woman living with HIV to her child during pregnancy, childbirth (also called labor and delivery), or breastfeeding (through breast milk). Mother-to-child transmission of HIV is also called perinatal transmission of HIV.

    The use of HIV medicines and other strategies have helped to lower the rate of mother-to-child transmission of HIV to 1% or less in the United States and Europe. (HIV medicines are called antiretrovirals.) 

  • Is HIV testing recommended for pregnant women?

    The Centers for Disease Control and Prevention (CDC) recommends that all women get tested for HIV before they become pregnant or as early as possible during each pregnancy. The earlier HIV is detected, the sooner HIV medicines can be started.

    Pregnant women with HIV take HIV medicines to reduce the risk of mother-to-child transmission of HIV. When started early, HIV medicines are more effective at preventing mother-to-child transmission of HIV. The HIV medicines will also protect the women’s health.

  • How do HIV medicines prevent mother-to-child transmission of HIV?

    HIV medicines prevent HIV from multiplying, which reduces the amount of HIV in the body (called the undetectable viral load is when the level of HIV in the blood is too low to be detected by a viral load test. The risk of mother-to-child transmission of HIV during pregnancy and childbirth is lowest when a woman with HIV has an undetectable viral load. Maintaining an undetectable viral load also helps keep the mother-to-be healthy.

    Some HIV medicines used during pregnancy pass from the pregnant woman to her unborn baby across the cesarean delivery (sometimes called a C-section) can reduce the risk of mother-to-child transmission of HIV in women who have a high viral load (more than 1,000 copies/mL) or an unknown viral load near the time of delivery.

    After birth, babies born to women with HIV receive HIV medicine to reduce the risk of mother-to-child transmission of HIV. Several factors determine what HIV medicine they receive and how long they receive the medicine.
  • Are HIV medicines safe to use during pregnancy?

    Most HIV medicines are safe to use during pregnancy. In general, HIV medicines don't increase the risk of birth defects. Health care providers discuss the benefits and risks of specific HIV medicines when helping women with HIV decide which HIV medicines to use during pregnancy or while they are trying to conceive.

  • Are there other ways to prevent mother-to-child transmission of HIV?

    Despite ongoing use of HIV medicines after childbirth, a woman with HIV can still pass HIV to her baby while breastfeeding. In the United States, infant formula is a safe and readily available alternative to breast milk. For these reasons, women with HIV who live in the United States should not breastfeed their babies.

    Additionally, babies should not eat food that was pre-chewed by a person with HIV.

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

    From CDC:

    From the Department of Health and Human Services:

Pre-Exposure Prophylaxis (PrEP)

  • Key Points

    • Pre-exposure prophylaxis (PrEP) is when people who don’t have HIV but who are at risk of getting HIV take HIV medicine every day to prevent HIV infection. PrEP is used by people without HIV who are at risk of being exposed to HIV through sex or injection drug use.
    • Two HIV medicines are approved by the U.S. Food and Drug Administration (FDA) for use as PrEP: Truvada and Descovy. PrEP is most effective when taken consistently each day.
    • The Centers for Disease Control and Prevention (CDC) reports that studies have shown that consistent use of PrEP reduces the risk of getting HIV from sex by about 99% and from injection drug use by at least 74%.
  • What is PrEP?

    PrEP stands for pre-exposure prophylaxis. The word “prophylaxis” means to prevent or control the spread of an infection or disease.

    PrEP is when people who don’t have HIV but who are at risk of getting HIV take HIV medicine every day to prevent HIV infection. PrEP is used by people without HIV who are at risk of being exposed to HIV through sex or injection drug use. Two HIV medicines are approved by the U.S. Food and Drug Administration (FDA) for use as PrEP: Truvada and Descovy. Which medicine to use for PrEP depends on a person’s individual situation.

    If a person is exposed to HIV through sex or injection drug use, having the PrEP medicine in the bloodstream can stop HIV from taking hold and spreading throughout the body. However, if PrEP is not taken every day, there may not be enough medicine in the bloodstream to block the virus.

  • Who should consider taking PrEP?

    PrEP is for people who don’t have HIV but who are at risk of getting HIV through sex or injection drug use. 

    Specifically, the Centers for Disease Control and Prevention (CDC) recommends that PrEP be considered for people who are HIV negative who have had anal or vaginal sex in the past 6 months and:

    • have a sexual partner with HIV (especially if the partner has an unknown or detectable viral load), or
    • have not consistently used a condom, or
    • have been diagnosed with a sexually transmitted disease (STD) in the past 6 months.

    PrEP is also recommended for people without HIV who inject drugs and:

    • have an injection partner with HIV, or
    • share needles, syringes, or other equipment to inject drugs.

    PrEP should also be considered for people without HIV who have been prescribed non-occupational post-exposure prophylaxis (PEP) and:

    • report continued risk behavior, or
    • have used multiple courses of PEP.

    If you think PrEP may be right for you, talk to your health care provider.

  • How well does PrEP work?

    PrEP is most effective when taken consistently each day. CDC reports that studies have shown that consistent use of PrEP reduces the risk of getting HIV from sex by about 99% and from injection drug use by at least 74%. Adding other prevention methods, such as condom use, along with PrEP can reduce a person’s risk of getting HIV even further.
  • Does PrEP cause side effects?

    In some people, PrEP can cause side effects, such as nausea. These side effects aren’t serious and generally go away over time. If you are taking PrEP, tell your health care provider if you have any side effect that bothers you or that does not go away.
  • What should I do if I think PrEP could help me?

    If you think PrEP may be right for you, see a heath care provider. PrEP can be prescribed only by a health care provider. If your health care provider agrees that PrEP may reduce your risk of getting HIV, the next step is an HIV test. You must be HIV negative to start PrEP.
  • What happens once I start PrEP?

    Once you start PrEP, you will need to take PrEP every day. PrEP is much less effective when it is not taken every day.

    Continue to use condoms while taking PrEP. Even though daily PrEP can greatly reduce your risk of HIV, it doesn’t protect against other STDs, such as gonorrhea and chlamydia. Combining condom use with PrEP will reduce your risk of HIV even further, as well as protect you from other STDs.  

    You must also take an HIV test every 3 months while taking PrEP, so you’ll have regular follow-up visits with your health care provider. If you are having trouble taking PrEP every day or if you want to stop taking PrEP, talk to your health care provider.

Post-Exposure Prophylaxis (PEP)

  • Key Points

    • Post-exposure prophylaxis (PEP) means taking HIV medicines within 72 hours after a possible exposure to HIV to prevent HIV infection.
    • PEP should be used only in emergency situations. It is not meant for regular use by people who may be exposed to HIV frequently.
    • PEP must be started within 72 hours (3 days) after a possible exposure to HIV. The sooner PEP is started after a possible HIV exposure, the better.
    • If you are prescribed PEP, you will take HIV medicines every day for 28 days.
  • What is PEP?

    PEP stands for post-exposure prophylaxis. The word “prophylaxis” means to prevent or control the spread of an infection or disease. PEP means taking HIV medicines within 72 hours after a possible exposure to HIV to prevent HIV infection.

    PEP should be used only in emergency situations. It is not meant for regular use by people who may be exposed to HIV frequently. PEP is not intended to replace regular use of other HIV prevention methods, such as consistent use of condoms during sex or pre-exposure prophylaxis (PrEP). PrEP is when people at risk for HIV take a specific HIV medicine daily to prevent getting HIV. For more information, see the ClinicalInfo fact sheets on The Basics of HIV Prevention and Pre-Exposure Prophylaxis (PrEP).

  • Who should consider taking PEP?

    PEP may be prescribed for people who are HIV negative or don’t know their HIV status, and in the last 72 hours:
    • May have been exposed to HIV during sex
    • Shared needles or other equipment (works) to inject drugs
    • Were sexually assaulted

    If you think you were recently exposed to HIV, talk to your health care provider or an emergency room doctor about PEP right away.

    In addition, PEP may be prescribed for a health care worker following a possible exposure to HIV at work, for example, from a needlestick injury. A health care worker who has a possible exposure to HIV should seek medical attention immediately.

  • When should PEP be started?

    PEP must be started within 72 hours (3 days) after a possible exposure to HIV. The sooner PEP is started after a possible HIV exposure, the better. According to research, PEP will most likely not prevent HIV infection if it is started more than 72 hours after a person is exposed to HIV.

    If you are prescribed PEP, you will need to take the HIV medicines every day for 28 days.

  • What HIV medicines are used for PEP?

    The Centers for Disease Control and Prevention (CDC) provides guidelines on recommended HIV medicines for PEP. The CDC guidelines include recommendations for specific groups of people, including adults and adolescents, children, pregnant women, and people with kidney problems. The most recent PEP recommendations can be found on CDC’s PEP resources webpage.

    Your health care provider or emergency room doctor will work with you to determine which medicines to take for PEP.

  • How well does PEP work?

    PEP is effective in preventing HIV infection when it’s taken correctly, but it’s not 100% effective. The sooner PEP is started after a possible HIV exposure, the better. While taking PEP, it’s important to keep using other HIV prevention methods, such as using condoms with sex partners and using only new, sterile needles when injecting drugs.

  • Does PEP cause side effects?

    The HIV medicines used for PEP may cause side effects in some people. The side effects can be treated and aren’t life-threatening. If you are taking PEP, talk to your health care provider if you have any side effect that bothers you or that does not go away.