What is human immunodeficiency virus (HIV)?

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

How do you get HIV?

HIV enters the bloodstream by way of body fluids, such as blood or semen. Once in the blood, the virus invades and kills CD4 cells. CD4 cells are key cells of the immune system. When these cells are destroyed, the body is less able to fight disease.

How do you get AIDS?

AIDS occurs when the number of CD4 cells decreases below a certain level and the person gets sick with diseases that the immune system would normally fight off. These diseases include pneumonia, certain types of cancer, and harmful infections.

How long does it take for HIV to develop into AIDS?

It can take months or years before HIV infection might develop into AIDS. Unless a woman gets tested, she may never know she is infected with HIV until she gets sick.

Click on the FAQs below to expand

Can HIV be treated?

HIV infection can be treated, but not cured. Taking anti-HIV drugs can help people with HIV infection stay healthy for a long time and can decrease the chance of passing the virus to others. There is no vaccine to prevent HIV infection.

If I am infected with HIV and pregnant, can I pass HIV to my baby?

It is possible to pass HIV to your baby in the following ways:

  • During pregnancy, HIV can pass through the placenta and infect the baby.
  • During labor and delivery, the baby may be exposed to the virus in the mother’s blood and other fluids. When a woman goes into labor, the amniotic sac breaks (her water breaks). Once this occurs, the risk of transmitting HIV to the baby increases. Most babies who get HIV from their mothers become infected around the time of delivery.
  • Breastfeeding also can transmit the virus to the baby.

What can I do to reduce the risk of passing HIV on to my baby?

You and your health care provider will discuss things you can do to reduce the risk of passing HIV on to your baby. They include the following:

  • Take a combination of anti-HIV drugs during your pregnancy as prescribed.
  • Have your baby by cesarean delivery if lab tests show that your level of HIV is high.
  • Take anti-HIV drugs during labor and delivery as needed.
  • Give anti-HIV drugs to your baby after birth.
  • Do not breastfeed.

By following these guidelines, 99% of HIV-infected women will not pass HIV to their babies.

Why is HIV treatment recommended during pregnancy?

Treatment during pregnancy has two goals: 1) to protect your own health, and 2) to help prevent passing HIV to your baby. Many combinations of drugs are used to manage HIV infection. This is called a “drug regimen.” Anti-HIV drugs decrease the amount of HIV in the body.

Are there any side effects of HIV drugs?

Drugs used to treat HIV infection may cause side effects. Common side effects include nausea, diarrhea, headaches, and muscle aches. Less common side effects include anemia, liver damage, and bone problems such as osteoporosis. While unusual, drugs used to treat HIV may affect the development of the fetus. However, not taking medication greatly increases the chances of passing the virus to your baby.

What is my viral load?

Your viral load is the amount of HIV that you have in your body.

Why is it important for my viral load and CD4 cell count to be monitored?

Both a high viral load and a low number of CD4 cells mean there is a greater risk of passing HIV to your baby and a greater risk of you becoming sick. However, even if you have a low viral load, it is still possible to pass HIV to the baby.

Should I still use condoms during sex even though I am pregnant?

If your partner also is infected with HIV, condoms help protect you and your partner from other infections. If your partner is not infected with HIV, in addition to using condoms, there are some drugs that partners can take that may decrease their risk of becoming infected.

Are there extra risks for me if I am HIV positive and I have a cesarean delivery?

Having a cesarean delivery may carry extra risks if you are HIV positive. Women with low CD4 cell counts have weak immune systems, so they are at greater risk of infection after surgery. The incision may heal more slowly. Drugs to prevent infection are given during cesarean delivery.

After I give birth, how will I know if my baby is infected with HIV?

Babies who are born to HIV-positive mothers are tested for HIV several times in the first few months. The test looks for the presence of the virus in the baby’s blood. The baby has HIV infection if two of these test results are positive. The baby does not have HIV infection if two of these test results are negative. Another type of HIV test is done when the baby is 12–18 months old.


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).

Amniotic Sac: Fluid-filled sac in the mother’s uterus in which the fetus develops.

Anemia: Abnormally low levels of blood or red blood cells in the bloodstream. Most cases are caused by iron deficiency, or lack of iron.

Cesarean Delivery: Delivery of a baby through an incision made in the mother’s abdomen and uterus.

Fetus: The developing offspring in the uterus from the ninth week of pregnancy until the end of pregnancy.

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.

Osteoporosis: A condition in which the bones become so fragile that they break more easily.

Placenta: Tissue that provides nourishment to and takes waste away from the fetus.

If you have further questions, contact your obstetrician–gynecologist.

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.