Objectives: Anti-Rhc antibodies may be the reason for the hemolytic disease of the newborn, therefore, noninvasive Rhc determination is important for pregnancy monitoring. For this purpose, we decided to introduce real-time polymerase chain reaction (PCR) method.
Methods: Blood from 200 donors, plasma and whole-blood from 11 Rhc-negative mothers, as well as blood from fathers and newborns were examined. Rhc sensitivity and specificity were first determined by real-time PCR using genomic DNA from donors. The same Rhc genotyping method was used for fetal Rhc detection in maternal plasma. To confirm the fetal Rhc-negative result, plasma was tested with a panel of biallelic insertion/deletion polymorphisms for the presence of fetal DNA.
Results: The c allele assay showed full specificity. The mean Ct value for one copy of c allele diluted in C-negative DNA was determined from extrapolating the correlation curve as 39.9. Full concordance was observed between the fetal Rhc genotypes from maternal plasma and the newborn phenotypes.
Conclusions: Preliminary results show that it is possible to examine fetal c allele of RHCE gene in the plasma of pregnant women with anti-c by means of a noninvasive method. The diagnostic accuracy of the procedure, however, has yet to be confirmed in a larger group.
Copyright (c) 2008 John Wiley & Sons, Ltd.