Prospective cohort study of children born to human immunodeficiency virus-infected mothers, 1985 through 1997: trends in the risk of vertical transmission, mortality and acquired immunodeficiency syndrome indicator diseases in the era before highly active antiretroviral therapy

Objectives. To assess changes in the risk of vertical transmission of HIV and changes in both mortality and morbidity among children in southern Connecticut with HIV infection after the introduction of treatment of RN-infected pregnant women with antiretroviral drugs and of regimens to prevent or to treat AIDS indicator diseases in infected children. Methods, The risk of vertical transmission of HN, the rates of death and of AIDS indicator diseases and temporal trends in each were determined for children born in the first 5 years of a prospective, longitudinal cohort study (Period 1: December 1, 1985, through November 30, 1990) compared with those for children born during the latter 7 years of the study (Period 2: December 1, 1990, through November 30, 1997). Results. Of 347 infants enrolled, HIV infection status could be determined for 341; 44 (12.9%) were infected. The risk of vertical transmission declined from 20.7% among children born in Period 1 to 6.5% among children born in period 2 (rate ratio, 3.2; 95% confidence interval, 1.7 to 6.0; P = 0.0001), Of the 21 infected children who died, 11(52%) were less than or equal to 18 months of age and 18 (86%) were less than or equal to 36 months of age at the times of death. Approximately one-fourth of infected children born during each period died at lr;18 months of age. Among those less than or equal to 36 months of age, 15 deaths occurred during 878 person months of observation for those born in Period 1 compared with 3 deaths that occurred during 334 person months for those born in Period 2 (rate ratio, 1.9; 95% confidence interval, 0.5 to 10.3; P = 0.45). Of the 44 children infected with HIV, 32 had one or more AIDS indicator diseases (a total of 67 episodes), 73% of which occurred when the children were less than or equal to 36 months of age. Among children born in Period 2, none developed Pneumocystis carinii pneumonia and the rates of Mycobacterium avium complex disease and of wasting syndrome declined, but the differences in rates of disease were not statistically significant. Conclusion. A substantial and statistically significant decline in the risk of vertical transmission of HIV-1 occurred during the 12-year study period. In contrast although there was a trend toward a decrease in mortality among HIV-infected children less than or equal to 36 months of age and changes in the overall rates of AIDS indicator diseases among children born in Period 1 compared with Period 2, the differences were not statistically significant.