Author/Authors :
Moezzi، Leili نويسنده Diagnostic Laboratory Sciences and Technology Research Center, Shiraz University of Medical Sciences , , Keshavarz، Zeinab نويسنده Diagnostic Laboratory Sciences and Technology Research Center, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran , , Ranjbaran، Ali Reza نويسنده Division of Uro-oncology, Department of Urology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran , , Aboualizadeh، Farzaneh نويسنده , , Behzad-Behbahani، Abbas نويسنده , , Abdullahi، Masooma نويسنده Diagnostic Laboratory Sciences and Technology Research Center, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran , , Ramezani، Amin نويسنده School of Advanced Medical Science and Technology, Shiraz University of Medical Sciences, Shiraz, Iran , , Samsami Dehaghani، Alamtaj نويسنده Department of Obstetrics and Gynecology, Shiraz University of Medical Sciences, Shiraz, Iran , , Sharifzadeh، Sedigheh نويسنده Diagnostic Laboratory Sciences and Technology Research Center, Shiraz University of Medical Sciences ,
Abstract :
Background: Maternal-fetal RhD antigen incompatibility causes approximately 50%
of clinically significant alloimmunization cases. The routine use of prophylactic anti-D
immunoglobulin has dramatically reduced hemolytic disease of the fetus and newborn.
Recently, fetal RHD genotyping in RhD negative pregnant women has been suggested for
appropriate use of anti-D immunoglobulin antenatal prophylaxis and decrease unnecessary
prenatal interventions.
Materials and Methods: In this prospective cohort study, in order to develop a reliable
and non-invasive method for fetal RHD genotyping, cell free fetal DNA (cffDNA)
was extracted from maternal plasma. Real-time quantitative polymerase chain
reaction (qPCR) for detection of RHD exons 7, 5, 10 and intron 4 was performed
and the results were compared to the serological results of cord blood cells as the
gold standard method. SRY gene and hypermethylated Ras-association domain family
member 1 (RASSF1A) gene were used to confirm the presence of fetal DNA in
male and female fetuses, respectively.
Results: Out of 48 fetuses between 8 and 32 weeks (wks) of gestational age (GA), we
correctly diagnosed 45 cases (93.75%) of RHD positive fetuses and 2 cases (4.16%) of the
RHD negative one. Exon 7 was amplified in one sample, while three other RHD gene sequences
were not detected; the sample was classified as inconclusive, and the RhD serology
result after birth showed that the fetus was RhD-negative.
Conclusion: Our results showed high accuracy of the qPCR method using cffDNA for
fetal RHD genotyping and implicate on the efficiency of this technique to predict the competence
of anti-D immunoglobulin administration.
