Use of interventions for reducing mother-to-child transmission of HIV in Australia.

Objective: To describe the extent and outcome of use of interventions for reducing the risk of HIV transmission from mother to child in Australia.
Design: National surveillance for perinatal exposure to HIV.
Participants and Setting: Notified cases of HIV infection in women in Australia and their perinatally exposed children, 1982-1999.
Outcome Measures: Trends over time in use of interventions (antiretroviral therapy in pregnancy, elective caesarean delivery and avoidance of breastfeeding) and perinatally acquired HIV infection.
Results: By 31 March 2000, 204 children were reported as having been born in 1982-1999 to 162 women whose HIV infection had been diagnosed by 31 December 1999. The child's HIV infection status was established for 182 (89.2%); the mother's HIV infection was diagnosed antenatally in 91 of these cases (50%). Among women diagnosed antenatally, use of elective caesarean delivery and antiretroviral therapy in pregnancy increased significantly, from 3% and 14% by women whose children were born in 1982-1993, to 21% (P=0.01) and 88% (P<0.001), respectively, by women whose children were born in 1994-1999. Most women (95%) diagnosed antenatally avoided breastfeeding their children. The percentage of infected children born to women diagnosed antenatally declined from 26% among children born in 1982-1993 to 19% among those born in 1994-1999. The percentage of infected children was significantly lower among those whose mothers used antiretroviral therapy in pregnancy (11% versus 36%; P=0.03).
Conclusion: Antiretroviral use in pregnancy, elective caesarean delivery and avoidance of breastfeeding have been effective interventions for reducing the risk of mother-to-child HIV transmission in Australia. While the rate of perinatal HIV transmission has declined, it remains high in comparison with rates reported from other industrialised countries.