Fetal RhD genotyping by real time quantitative PCR in maternal plasma of RhD-negative pregnant women from the Sahel of Tunisia Génotypage RhD fetal par PCR quantitative en temps réel à partir du plasma maternel des femmes enceintes RhD-négatif dans le Sahel tunisien

Objective: The aim of this study was to evaluate the diagnostic value of RhD fetal genotyping from the plasma of RhD-negative pregnant women. Methods: We analysed the plasma samples of 65 pregnant women. DNA quan- tification was done using real time quantitative PCR (RQ-PCR) in multiplex targeting multiple RhD exons 5, 7 and 10, with a standardized pool of plas- mid calibrators. Results were compared with serological analysis of cord blood after delivery. Results: Fetal RhD status was predicted with 95.38% accuracy from maternal plasma of pregnant women in the 11 th to 40 th weeks of ges- tation. One false positive but no false negative results were found. Thus the sensitivity of the assay was 100% and the specificity was 94.44 %. Conclu- sion: The present data demonstrates that the fetal RhD genotyping approach could be achieved efficiently with RQ-PCR for RhD-negative tunisian pregnant women.