Fetal Rhesus D mRNA Is Not Detectable in Maternal Plasma

Detection of fetal-derived DNA and RNA molecules in maternal plasma is a promising approach for noninvasive prenatal diagnosis (1). Analysis of circulating fetal RNA, unlike analysis of fetal Y-chromosomal DNA, can be used in pregnancies with fetuses of either gender(2). Placenta-derived mRNA species are readily detectable in maternal plasma(2). The fetal hematopoietic compartment may be another source of nucleic acids in maternal plasma(3). Wataganara et al.(4) reported detection of γ-globin mRNA in maternal plasma. However, expression of γ-globin is not a fetus-specific phenomenon and is shared by maternal erythroid cells(5), and γ-globin mRNA is readily detectable in nonpregnant individuals(4). In this study, we assessed whether rhesus D ( RHD gene) mRNA derived from fetal erythroid cells is detectable in the plasma of rhesus D-negative pregnant women. Fifteen rhesus D-negative women at 11–40 weeks of gestation (Table 1⇓ ), attending the University Women’s Hospital, Basel, were recruited with informed consent and institutional ethics approval. Trisomy 21 was subsequently …