Mother-to-child transmission of HIV
Mother-to-child transmission of HIV
Children can become infected with HIV in utero during their mother's pregnancy, during childbirth and after birth through breastfeeding.
In the absence of preventive measures, the risk of an HIV-positive mother infecting her newborn is 15 to 30 per cent. If the mother is on antiretroviral therapy during pregnancy and breastfeeding, the risk of HIV transmission to her baby is very low.
During pregnancy, the mother's blood and the baby's blood do not mix, but there is a constant exchange of various substances between the mother and the baby in the placenta. Usually, the virus does not cross the placental barrier, but if the mother has any illness, then the probability of the virus entering the child's body through the placenta increases. Today, therapy can reduce the amount of virus in the mother's body to undetectable levels. Therefore, with the right medication, the risk of HIV transmission to a child in the womb is greatly reduced.
During childbirth, the baby passes through mother’s birth canal and comes into contact with the mother’s mucous membranes. The newborn can get the virus through the vaginal fluid. In addition, ruptures, micro traumas and tears are common during childbirth. The baby thus can come into contact with the mother's blood, which contains the virus. Certain methods of delivery and antiretroviral therapy can reduce the risk of transmission of the virus during childbirth.
Breast milk contains HIV, which can be passed on to the newborn if the mother doesn’t receive antiretroviral therapy. The newborn’s digestive system is underdeveloped and abundantly supplied with blood, which increases the risk of the virus entering the digestive tract. Due to the specifics of the adult digestive system the virus cannot enter the adult bloodstream in this way.
How to prevent mother-to-child transmission of HIV
- Women should be tested for HIV before pregnancy, or as early as possible during each pregnancy. The sooner HIV is detected, the sooner HIV therapy can be started and the risk of passing the infection to the baby can be significantly reduced.
- In all countries, the use of antiretrovirals (ARVs) and other strategies has helped reduce mother-to-child transmission of HIV to 2 per cent or less.
- HIV-positive pregnant women should take antiretroviral drugs throughout pregnancy and childbirth to prevent transmission of the virus. Planned caesarean sections can reduce the risk of perinatal HIV transmission in women with a high or unknown viral load shortly before delivery.
- After birth, children born to HIV-infected women should receive antiretroviral drugs to reduce the risk of infection. Antiretroviral drugs for newborns are prescribed by a health-care professional.
- Pregnant women with HIV are encouraged to discuss options with health-care providers for breastfeeding their baby. With continued use of antiretroviral drugs and an undetectable viral load during pregnancy and breastfeeding, the risk of transmission to the breastfed infant is low, less than 2 per cent, but not zero. Therefore, commercial breast-milk substitutes can be used as an alternative to eliminate the risk of virus transmission to the infant after birth, after their acceptability, feasibility, availability, accessibility and safety have been evaluated.
- Laboratory diagnosis of HIV infection in newborns is performed according to national protocols. The mother of the child should discuss the timing of test with the health-care provider. Health-care professionals will explain the results of the test and the need for additional testing to definitively establish the child's HIV status.
Most HIV drugs are safe to use during pregnancy and do not increase the risk of birth defects in the fetus. However, health care providers should discuss the benefits and risks of specific ARVs when helping pregnant women with HIV decide which drugs to use during pregnancy or while trying to become pregnant.
