OBJECTIVE: Anti-D immunoglobulin is applied to all pregnant women having RhD 
incompatibility to prevent hemolytic disease of the newborn. The aim of this 
study is to determine fetal RhD status in the Rh incompatible pregnancies with 
an non-invasive technique; free fetal DNA isolation from maternal circulation. 
In the case of Rh incompatibility especially with a history of previous fetal 
anemia, it can be beneficial to know Rh status antenatally in terms of 
monitoring fetuses with Rh positive [RhD(+)] status consciously.
MATERIALS AND METHODS: Total free DNA was isolated in 50 Rh negative [RhD(-)] 
pregnant women, who had RhD alloimmunisation with their husbands. The gene in 
isolated DNA was investigated with TagMan prob and real time PCR by using 
primers belonging to exon 7 of the RhD gene.
RESULTS: The authors analyzed 50 RhD(-) women by using quantitative real time 
PCR technique. Five of them were RhD(-) and the rest of them were found to be 
RhD(+). After birth one of the infants who were analyzed as RhD(+) were found to 
be RhD(-).
CONCLUSION: The detection of fetal RhD status by using a non-invasive method 
from maternal circulation was found to be possible. Assessing fetal RhD status 
non-invasively by using free fetal DNA in maternal blood will be cost-efficient, 
avoiding unnecessary indirect Coombs test and unnecessary Rhogam applications 
that is used in RH incompatible pregnancies. This study will throw a fresh light 
on prenatal diagnosis.