Fetal transcripts in maternal blood

The discovery of fetal mRNA transcripts in maternal circulation holds great promise for noninvasive prenatal diagnosis. To identify potential fetal biomarkers, we studied whole blood and plasma transcripts common to term pregnant women and their newborns but reduced or absent in the postpartum mothers. In whole blood, 157 potentially-fetal transcripts were identified. RT-PCR confirmed the presence of specific transcripts, SNP analysis confirmed the presence of fetal transcripts in maternal circulation. Comparison of whole blood and plasma samples from the same women suggested that placental genes are more easily detected in plasma. We conclude that fetal and placental mRNA circulates in the blood of pregnant women. [I] We profiled whole antepartum (A), postpartum (P), and umbilical cord (U) blood samples from each of 9 mothers and their 10 newborns (1 set of twins, denoted as a and b after the sample names). [II] We also profiled plasma samples (A, P, and U) from three of those mothers to allow for a direct comparison between blood and plasma.