Perinatal transmission of HIV from mother to child can occur during pregnancy, labor & delivery, and breastfeeding.

Women living with HIV (WLWH) in high resource countries are advised to not breastfeed because of known transmission of the HIV virus via breastmilk¹, and because formula feeding is believed to be safe and available.

There has been increasing interest in breastfeeding among WLWH in high resource countries who are on anti-retroviral therapy (ART) with undetectable viral loads (undetectable HIV RNA in plasma)². Transmission of HIV virus from mother to infant has been shown to be markedly reduced if mother takes ART during pregnancy, labor & delivery, and postpartum, with the infant also being treated with ART. However, we don’t have data on the risk of transmission of HIV via breastmilk in WLWH who have undetectable HIV RNA loads.

The Undetectable=Untransmittable Campaign³ stresses that people living with HIV who have undetectable viral loads are not at risk for transmitting the HIV virus to others sexually. Unfortunately, ART during breastfeeding has not definitely shown to prevent HIV virus transmission via breastmilk because the virus infects immune cells, which are abundant in breastmilk. ART does not eliminate HIV from infected immune cells^1,4.

It is estimated that the risk of HIV transmission via breastfeeding from a WLWH with an undetectable viral load is 1% or less⁵.

The World Health Organization⁶ recommends that HIV-infected mothers breastfeed exclusively for the first 6 months of life and continue breastfeeding for at least 12 months, with the addition of complementary foods. They may breastfeed for 24 months or longer, while being fully supported in the monitoring for ART adherence. Once the infant has access to a nutritionally adequate and safe diet without breastmilk, then breastfeeding should stop.