ABSTRACT
OBJECTIVE: The aim of this study was to assess predicted Down syndrome risk, based on three serum analytes (triple test), with HIV infection status and antiretroviral therapy regimen. METHODS: Screening results in 72 HIV-positive women were compared with results from age-matched and race-matched HIV-negative controls. Mean concentrations of each analyte were compared by serostatus and antiretroviral therapy. Observed Down syndrome incidence in the offspring of HIV-positive women was calculated from national HIV surveillance data. RESULTS: Overall, women with HIV had a significantly higher probability of receiving a 'high-risk' result than uninfected controls (p = 0.002). Compared with matched uninfected controls, women with HIV infection had significantly higher human chorionic gonadotrophin, lower unconjugated estriol, and higher overall predicted risk of their infant having Down syndrome (1/6250 vs. 1/50 000 p = < 0.001). National surveillance data show no evidence of higher than expected incidence of Down syndrome in the offspring of HIV-positive women. CONCLUSIONS: HIV infection impacts the serum analytes used to assay for Down syndrome risk resulting in a high rate of 'high risk' results. However, there is no population-based association between maternal HIV infection and Down syndrome. Care should be taken when interpreting high-risk serum screening results in HIV-positive women to avoid unnecessary invasive diagnostic procedures.
