The transmission of HIV from an HIV-positive mother to her child during pregnancy, labour, delivery or breastfeeding is called vertical or mother-to-child transmission (MTCT). In the absence of any interventions during these stages, rates of HIV transmission from mother-to-child can be between 15–45%. MTCT can be nearly fully prevented if both the mother and the baby are provided with ARV drugs as early as possible in pregnancy and during the period of breastfeeding.

WHO recommends lifelong ART for all people living with HIV, regardless of their CD4 count clinical stage of disease, and this includes women who pregnant or breastfeeding. In 2018, 82% of the estimated 1.3 million pregnant women living with HIV globally received ARV treatments to prevent transmission to their children. A growing number of Member States are achieving very low rates of MTCT and some (Antigua and Barbuda, Armenia, Belarus, Cuba, Malaysia, Maldives, St Kitts and Nevis and Thailand) have been formally validated for elimination of MTCT of HIV as a public health problem. Several countries with a high burden of HIV infection are also progressing along the path to elimination.