Answer:
Pregnant women are typically tested for HIV as a routine part of prenatal care, ideally during the first trimester of pregnancy. This is important because if a pregnant woman is HIV-positive, there are treatments available that can reduce the risk of passing the virus on to her baby during pregnancy, childbirth, or breastfeeding.
If a pregnant woman has not been tested for HIV prior to becoming pregnant, or if she engages in behaviors that put her at increased risk for HIV infection during pregnancy, she may be tested again during the second or third trimester. Additionally, some healthcare providers may recommend re-testing for HIV later in the pregnancy if the woman has a known exposure to the virus, such as through unprotected sex with an HIV-positive partner