The diagnostic accuracy of non-invasive fetal RhD genotyping by using cell-free fetal DNA in maternal plasma

Introduction: The non-invasive prenatal diagnosis of the fetus RhD genotype in RhD incompatibility has a crucial role in the prevention of increased anti-D immunoglobulin therapy for haemolytic diseases in pregnant women carrying RhD negative fetus. It was aimed to detect fetal RhD genotyping by using maternal circulating cell-free DNA in the current study.Methods: Maternal blood samples were collected in different trimester of pregnancies (12-40 weeks) in 12 D-negative mothers. Cell-free fetal DNA was extracted from 2 ml of maternal plasma by an conventional DNA isolation technique (Qiagen, Hilden, Germany) and real-time PCR was performed for genotyping target RhD exons 7 and 10 and GLO genes. Postnatal serological evaluations were performed and the results were confirmed.Results: 6 cases (50 %) were determined D positive and 6 cases (50 %) were determined D negative. All results were also confirmed after birth serologically. Conclusions: In conclusion, the current results showed us the non-invasive target RhD genotyping from cell free fetal DNA from maternal plasma samples have a diagnostic accuracy in RhD incompatibility pregnancies.