Women's Health
FAQ195, January 2018

PDF Format

Preventing HIV With Medication

What is human immunodeficiency virus (HIV)?

Human immunodeficiency virus (HIV) is the virus that causes acquired immunodeficiency syndrome (AIDS).

How is HIV passed from person to person?

HIV is passed through contact with an infected person’s body fluids, such as semen, vaginal fluid, or blood. This can happen during sex or by sharing needles used to inject illegal drugs. An infected woman who is pregnant can pass the virus to her fetus during labor. Women with HIV who breastfeed also can pass the virus to their babies.

How does HIV affect the body?

Once HIV is in your body, it attacks the immune system. As the immune system weakens, it is less able to resist disease and infections. AIDS is diagnosed when a person infected with HIV develops diseases that the immune system normally would fight off. These diseases include pneumonia, certain types of cancer, and harmful infections.

How is HIV infection treated?

There is no cure for HIV infection, but it can be treated. Drugs are available that can help people with HIV stay healthy for a long time. The earlier treatment is started, the better for your long-term health. Early treatment also reduces your risk of giving the virus to uninfected sex partners.

Should I be tested for HIV?

It is important for all women to be tested for HIV at least once during their lifetime. HIV testing also is recommended for women who are pregnant or who are thinking about getting pregnant.

What is pre-exposure prophylaxis (PrEP)?

Pre-exposure prophylaxis (PrEP) is a pill that you take once a day. This pill contains two medications: 1) tenofovir and 2) emtricitabine. If you are exposed to HIV, these medications prevent HIV from causing infection.

Who is PrEP recommended for?

PrEP is recommended for people who are at high risk of HIV infection but who are HIV negative.

How do I know if I am at high risk of HIV infection?

An HIV-negative woman with a male sex partner who has HIV or AIDS is at high risk of HIV infection. If you are sexually active in an area that has a high number of HIV-positive people, you also may be at high risk of infection if one or more of the following apply to you:

  • You do not use condoms at all or do not use them each time you have sex.
  • You have a sexually transmitted infection (STI).
  • You exchange sex for drugs, money, food, or shelter.
  • You inject illegal drugs.
  • You are dependent on alcohol.

How do I know if I can take PrEP?

If you are thinking about taking PrEP, you will be tested for HIV. If you are infected with HIV, you will need HIV treatment. If you are not infected, your obstetrician–gynecologist (ob-gyn) or other health care professional may prescribe PrEP.

How often do I take PrEP?

You must take a pill once a day. Missing doses can lower the medication’s effectiveness and put you at risk of HIV infection.

What are some possible side effects of PrEP?

The most common side effects of PrEP include the following:

  • Stomach pain
  • Headache
  • Weight loss
  • Nausea and diarrhea

These side effects usually go away on their own after a few weeks. Serious side effects of PrEP include liver problems and a condition called lactic acidosis, which happens when there is too much acid in the blood.

Do I need to use condoms while taking PrEP?

PrEP by itself is not guaranteed to prevent HIV infection. You also need to follow safe sex practices while taking PrEP:

  • Know your sexual partners and limit their number—Your partner’s sexual history is as important as your own. The more partners you or your partners have, the higher your risk of getting HIV or other STIs.
  • Use condoms—Using a latex or polyurethane condom every time you have vaginal, oral, or anal sex decreases the chances of HIV infection.

Do I need to do anything else while taking PrEP?

While you are taking PrEP, you will need to be tested for HIV every 2–3 months. This is to make sure that you have not become infected. You also may be tested for certain STIs if you have risk factors for them. Some STIs increase your risk of getting infected with HIV. Treating these STIs can lower your HIV risk.

How much does PrEP cost?

PrEP can be expensive. Most insurance carriers cover all or part of the cost of PrEP. If PrEP is not covered by your insurance, or if you do not have health insurance, you may be able to get help with the cost. For more information, visit www.cdc.gov/hiv/pdf/risk/prep/cdc-hiv-paying-for-prep.pdf.

What steps are needed if I want to get pregnant with my HIV-positive male partner?

Talk with your ob-gyn or other health care professional about how to prevent infection. Steps to prevent HIV infection include the following:

  • Your partner should undergo treatment for HIV infection (if he is not already).
  • Have unprotected sex only when your partner has a low or undetectable viral load. Viral load is the amount of HIV in the body. Treatment often causes a person’s viral load to become very low or “undetectable” (meaning that HIV cannot be found with a laboratory test). Waiting until your partner has a low or undetectable viral load decreases the risk that you will become infected with HIV during unprotected sex.
  • Have unprotected sex only on the days that you are most likely to get pregnant. You can track these days with home ovulation kits purchased from a pharmacy. You should use condoms at all other times.

Can I use PrEP when I am trying to get pregnant?

HIV-negative women can use PrEP when trying to get pregnant. You should start taking PrEP 1 month before you start trying to get pregnant and continue for 1 month after you have gotten pregnant. PrEP is especially recommended if your partner’s viral load is detectable or unknown.

How can I prevent HIV infection during pregnancy?

Once you are pregnant, it is important to prevent HIV infection by always using condoms. You also can consider taking PrEP while pregnant.

Is PrEP safe to take during pregnancy?

Most experts agree that PrEP is safe during pregnancy. The drugs in PrEP are used to safely treat women with HIV during pregnancy. There are no reports of birth defects caused by PrEP.

Should I take PrEP while breastfeeding?

If you are HIV negative and at high risk of HIV infection, you can take PrEP while you are breastfeeding. Although the drugs in PrEP can be found in breast milk, the amount is small and not likely to harm the baby. You also should continue to use condoms while you are breastfeeding and taking PrEP.

Are there other options for getting pregnant?

An HIV-negative woman can use sperm from an HIV-negative donor. This may involve the use of intrauterine insemination (IUI) or in vitro fertilization (IVF). You also can use your partner’s sperm that has been treated in a laboratory to remove the virus, and then undergo IUI or IVF. These options may be costly and may not be covered by insurance.


Acquired Immunodeficiency Syndrome (AIDS): A group of signs and symptoms, usually of severe infections, occurring in a person whose immune system has been damaged by infection with human immunodeficiency virus (HIV).

Human Immunodeficiency Virus (HIV): A virus that attacks certain cells of the body’s immune system and causes acquired immunodeficiency syndrome (AIDS).

Immune System: The body’s natural defense system against foreign substances and invading organisms, such as bacteria that cause disease.

Intrauterine Insemination (IUI): A procedure in which a man’s semen is placed into a woman’s vagina, cervix, or uterus.

In Vitro Fertilization (IVF): A procedure in which an egg is removed from a woman’s ovary, fertilized in a laboratory with the man’s sperm, and then transferred to the woman’s uterus to achieve a pregnancy.

Obstetrician–Gynecologist (Ob-Gyn): A physician with special skills, training, and education in women’s health.

Ovulation: The release of an egg from one of the ovaries.

Pre-exposure Prophylaxis (PrEP): Daily use of medication to prevent a person from becoming infected by human immunodeficiency virus (HIV).

Semen: The fluid made by male sex glands that contains sperm.

Sexually Transmitted Infection (STI): An infection that is spread by sexual contact, including chlamydia, gonorrhea, human papillomavirus (HPV), herpes, syphilis, and human immunodeficiency virus (HIV, the cause of acquired immunodeficiency syndrome [AIDS]).

If you have further questions, contact your obstetrician–gynecologist

FAQ195: Designed as an aid to patients, this document sets forth current information and opinions related to women’s health. The information does not dictate an exclusive course of treatment or procedure to be followed and should not be construed as excluding other acceptable methods of practice. Variations, taking into account the needs of the individual patient, resources, and limitations unique to the institution or type of practice, may be appropriate.

Copyright January 2018 by the American College of Obstetricians and Gynecologists

American College of Obstetricians and Gynecologists
409 12th Street SW, Washington, DC  20024-2188
Mailing Address: PO Box 96920, Washington, DC 20024-9998