Fetal RHD genotyping of RhD negative women by Real-time PCR

The RhD antigens play a significant role in Hemolytic Disease of the Fetus and Newborn (HDFN). The intention of this study is to determine the RHD fetal genotype in the maternal plasma of RhD negative pregnant women and sex determination of the fetus in the initial weeks of pregnancy by Real-time PCR technique.
In this descriptive study, we used 21 plasma samples from RhD negative pregnant women. DNA was extracted from samples by Cinnapure DNA Kit. Real time PCR reactions were done with specific primers for RHD gene exons 5, 7 and 10, and beta-globin and SRY genes. The sex and Rh phenotype of children were obtained after delivery.
Among the pregnant women, 11 (52.4%) were carrying male and 10 (47.6%) were carrying female fetuses. Out of 11 male fetuses, 10 (91%) were RhD-positive and one (9%) was RhD-negative. Out of 10 female fetuses, 9 (90%) were RhD-positive and one (10%) was RhD-negative. All prenatal genotype testing results were in concordance with postnatal RhD status and fetal sex without any false- positive or -negative results.[Okhovat1]
Performing Real-time PCR on CffDNA showed accurate, efficient and reliable results, allowing rapid and high throughput noninvasive prenatal diagnosis and determination of fetal sex and RhD status in clinical samples. This method helps RhD negative pregnant women with the proper use of immunoglobulin D and on the management and prevention of Hemolytic Disease of the Fetus and Newborn (HDFN).