HIV is a virus that can cause problems with the body's immune system. A weak immune system lowers the body's ability to fight infections and certain cancers over time. When cells of the immune system have been severely weakened or destroyed by HIV, it causes AIDS. Most people who have HIV will not develop AIDS unless they aren't treated. AIDS is when the HIV infection is in its most advanced stages.

Some people may get a flu-like illness within a month or two after infection with HIV. Many people don't have any symptoms when they are first infected. But HIV/AIDS is a serious infection that needs medical attention. If not treated, it can turn into a severe illness over time and cause life-threatening problems and early death.

If you have HIV, you can pass it to your baby during pregnancy, labor and delivery, and breastfeeding if your infection is not under complete control. Nearly all children under the age of 13 with HIV were infected by their mother. This happens in the womb, or as they passed through the birth canal during labor. The virus can also be passed through breastmilk.

A pregnant woman with untreated HIV has a 1 in 4 chance that her baby will get the virus. But with early diagnosis and treatment with antiretroviral medicines, you can reduce this risk to near zero.

Experts advise that almost all people with HIV be treated for the infection. If you have HIV and are planning to become pregnant, get treated for your HIV as soon as possible. Take your medicines every day as directed. Also, make sure your viral load is "undetectable" before and throughout pregnancy.

All pregnant women should get tested for HIV. Get the tests as early as possible in pregnancy, every time you are pregnant. Many women should be retested in the third trimester if they are at high risk of getting HIV, including people with multiple sex partners and those who inject illegal drugs. Your doctor may test you again for HIV during your third trimester even if you are not at high risk. Blood tests are the most common way to diagnose HIV. Other tests can check for HIV in saliva. But saliva tests are generally not as accurate as blood tests. When a test is positive, you'll have more tests to check the results of the first test. When a test is negative, but you may have been exposed to HIV recently, you'll need follow-up testing in a few weeks.

If you have HIV, you'll need extra health care during pregnancy. This will include antiretroviral medicines, possibly vaccines, and other preventive treatments. You'll need to work with a doctor who's trained in high-risk pregnancy, infectious disease, or HIV medicine.

You'll need regular blood tests to check the amount of HIV in your body. Your HIV should be completely controlled, or "undetectable." This will help minimize the risk of your baby picking up HIV.

Vaginal birth can expose a baby to the HIV virus, particularly if your HIV is detectable. If that is the case, talk with your doctor about whether you should have a C-section (cesarean) birth. A C-section helps reduce the risk of spreading the virus to your baby if your virus is not completely under control with medicines.

Babies of mothers with HIV are watched closely. Your baby will be given anti-HIV medicines after birth. Your baby will have regular exams and blood tests. In most cases, a diagnosis of HIV infection can be made by the time a baby is 3 months old.

Because HIV can be passed on through human milk, you shouldn't breastfeed your baby. Talk with your doctor about formula feeding.

There is no cure for HIV/AIDS. But antiretroviral medicines can help people infected with the virus to lead healthier, longer, and often normal lives. It's important to work with a specialist who treats HIV/AIDS and to follow your treatment plan carefully.

Contact your doctor if you:

• Are pregnant
• Think you have had contact with HIV
• Have HIV/AIDS and have an infection or new symptoms

To help lower the risk to your baby:

• Get tested during pregnancy. All pregnant women should have an HIV test at least once during pregnancy and sometimes twice (early and in the third trimester).
• Get treated before and during pregnancy. Work with a specialist who can treat HIV during pregnancy. Take your medicine exactly as directed.
• Don't breastfeed. Talk with your doctor about formula feeding.