The comparison of the performance of two screening strategies identifying newly-diagnosed HIV during pregnancy

In the Netherlands, a non-selective opt-out instead of a selective opt-in antenatal HIV screening strategy was implemented in 2004. In case of infection, screening was followed by prevention of mother-to-child-transmission (PMTCT). We compared the performance of the two strategies in terms of detection of new cases of HIV and vertical transmission. HIV-infected pregnant women were identified retrospectively from the Dutch HIV cohort ATHENA January 2000 to January 2008. Apart from demographic, virological and immunological data, the date of HIV infection in relation to the index pregnancy was established. Separately, all infants diagnosed with HIV born following implementation of the screening program were identified by a questionnaire via the paediatric HIV centres. 162/481 (33.7%) HIV-positive pregnant women were diagnosed with HIV before 2004 and 172/214 (80.3%) after January 2004. Multivariate analysis showed an 8-fold (95% confidence interval 5.47-11.87) increase in the odds of HIV detection during pregnancy after the national introduction of the opt-out strategy. Still, three children born during a 5-year period after July 2004 were infected due to de novo infection in pregnancy. Implementation of a nation-wide screening strategy based upon non-selective opt-out screening followed by effective PMTCT appeared to detect more HIV-infected women for the first time in pregnancy and to reduce vertical transmission of HIV substantially. Nonetheless, still few children are infected because of maternal infection after the first trimester. We propose the introduction of partner screening on HIV as part of the antenatal screening strategy