To describe the pattern of perinatal HIV exposure and outcomes among children born in Australia, 1982–2006.

National surveillance for perinatal HIV exposure.

Women with HIV infection and their perinatally exposed children.

Trends in the age-standardised rate of perinatal exposure, uptake of interventions by women with an antenatal HIV diagnosis, and rate of mother-to-child transmission.

Between 1982 and 2006, there were 354 reported cases of perinatal HIV exposure among children born in Australia. The age-standardised rate of perinatal exposure per 100 000 live births increased from 2.3 (1982–1986) to 5.1 (1991–1998), 9.9 (1999–2002) and 8.3 (2003–2006). Among children whose mother was diagnosed antenatally, the mother-to-child transmission rate declined significantly, from 25% (4/16; 95% CI, 7%–52%) in 1987–1990 to 5% (4/82; 95% CI, 1%–12%) in 2003–2006 (P < 0.001). The rate declined from 8% (4/51; 95% CI, 2%–19%) in 1987–1998 to 1% (2/151; 95% CI, 0.2%–5%) in 1999–2006 among children whose mother used at least two interventions. Mother-to-child transmission remained high among children born to women diagnosed postnatally (39/87, 45%; 95% CI, 34%–56%) and to women diagnosed antenatally who used no interventions (7/15, 47%; 95% CI, 21%–73%).

The increasing rate of perinatal exposure and the decreasing rate of mother-to-child transmission among children whose mothers’ HIV infection was diagnosed antenatally were temporally associated with use of interventions for minimising mother-to-child transmission. Mother-to-child transmission remained high when the mother’s HIV infection was not known during pregnancy.