In Africa, where a pregnant woman living with HIV lives has a big influence on whether her baby will be born HIV-free, and, if not, how her infant will acquire HIV.

There are a many reasons for vertical (mother-to-child) transmission of HIV, including: women not receiving antenatal and prevention of vertical HIV transmission services during pregnancy or breastfeeding; women starting antiretroviral therapy but falling out of care during pregnancy or breastfeeding; and women becoming infected with HIV during breastfeeding or pregnancy. However, not all countries face the same challenges, and to make rapid progress in eliminating vertical transmission it is crucial to know which means of transmission is contributing to the most new HIV infections among children in a country or region.

While the causes of vertical transmission of HIV in different regions vary, one thing is sure: far too many babies are still becoming infected with HIV.