Use of maternal plasma for non-invasive prenatal diagnosis of fetal ABO genotypes.
BACKGROUND
Measurement of free fetal DNA in maternal plasma opened a door for non-invasive prenatal diagnosis. Prenatal diagnosis of fetal ABO genotypes can provide a basis for the prevention and therapy of maternal-fetal incompatibility. We identified fetal ABO genotypes using fetal DNA in plasma from pregnant women with blood group O. The aim of the study was to investigate the accuracy and feasibility of this method.


METHODS
A total of 105 blood group O women in middle or late pregnancy were enrolled. Fetal DNA in maternal plasma and genomic DNA in umbilical vein blood from newborns were extracted using a QIAamp DNA Blood Kit. DNA was amplified to identify ABO genotypes by PCR with sequence-specific primers (PCR-SSP). The genotype results were evaluated using serologic tests for ABO phenotyping.


RESULTS
Using DNA from umbilical vein blood, ABO genotypes of 105 newborns were successfully identified by PCR-SSP. Using fetal DNA from maternal plasma, 88.6% (93/105) fetal ABO genotypes was correct; 12 false results were from 66 pregnant women with fetuses of type non-O. The accuracy in middle pregnancy was lower than that in late pregnancy, although the difference was not significant (0.05<p<0.10).


CONCLUSIONS
It is feasible to use measurement of fetal DNA in plasma from pregnant women with blood group O for prenatal diagnosis of fetal ABO genotypes. The method is useful for the diagnosis and therapy of ABO maternal-fetal incompatibility and hemolytic disease of the newborn.
Meng
Jin-Lai
JL
Department of Obstetrics and Gynecology, Shandong Provincial Hospital of Shandong University, Jinan, China.
Wang
Xie-Tong
XT
Wang
Yu
Y
Yue
Ya-Fei
YF
Wang
Xin
X
Chen
Zi-Jiang
ZJ
D000017:ABO Blood-Group System / Q000235:genetics*; D004247:DNA / Q000097:blood; D005260:Female; D005312:Fetal Blood; D005333:Fetus; D005838:Genotype; D006801:Humans; D009035:Mothers; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*
D000017:ABO Blood-Group System; D004247:DNA