Factors affecting transmission

Certain factors may increase the chance of mother-to-child (MTCT) HIV transmission:

  • Advanced HIV disease
  • Anaemia
  • Breastfeeding; mixed feeding (breast and formula)
  • Frequent unprotected se
  • Cervical or vaginal infections
  • Chorioamnionitis (inflammation of the membranes that cover the foetus)
  • Co-infection with other infectious illnesses
  • Genetic factors (of mother, infants, or virus)
  • High viral load
  • HIV-related wasting
  • Illicit drug use during pregnancy
  • Low CD4 cell count or CD4 percentage
  • Low maternal antibodies
  • Older age
  • Premature delivery
  • Prolonged or difficult labour
  • Smoking during pregnancy
  • Unprotected sex
  • Waters breaking more than four hours before delivery.
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 It may have been superseded by more recent developments.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.