Mother-to-baby transmission of HIV

An HIV-positive woman can pass on HIV to her baby during pregnancy, or during delivery, or by breastfeeding.

HIV treatment can, however, greatly reduce the risks of a woman passing on HIV to her baby. Appropriately managing labour can reduce the risks even further. The exclusive use of formula feed is strongly recommended for all babies with HIV-positive mothers in the UK. Using these methods, it’s possible to reduce the risk of mother-to-baby transmission of HIV from about one in four to less than one in a hundred.

A number of factors can make it more likely that a woman will pass on HIV to her baby. These include:

  • Being ill because of HIV.
  • Having a high HIV viral load and a low CD4 cell count.
  • Waters breaking four hours or more before delivery.
  • Having an untreated sexually transmitted infection at the time of delivery.
  • Using recreational drugs, particularly injected drugs, during pregnancy.
  • Having a vaginal delivery (rather than a caesarean delivery) if HIV viral load is detectable.
  • Having a difficult delivery, requiring, for example the use of forceps.
  • Breastfeeding.
This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.