No correlation between the number of fetal nucleated cells and the amount of cell-free fetal DNA in maternal circulation either before or after delivery.

OBJECTIVES: We have determined the number of fetal nucleated cells and the concentration of cell-free fetal DNA in parallel in the same maternal blood samples either before or after delivery, and studied the relationship between these two. METHODS: Venous blood samples were taken at four points around delivery from ten women who had singleton male fetus with informed consent. The number of fetal nucleated cells having a Y chromosome specific signal treated by two-color fluorescence in situ hybridization technique was counted using maternal whole blood. The concentration of sex-determining region Y gene sequence was determined using real-time quantitative PCR. RESULTS: The number of fetal nucleated cells decreased after delivery, and some fetal cells were present 1 month after delivery. While cell-free fetal DNA decreased rapidly after delivery and became undetectable 1 day after delivery in eight out of ten cases. The number of fetal nucleated cells did not correlate with the concentration of cell-free fetal DNA in maternal circulation. CONCLUSION: The present study demonstrates that cell-free fetal DNA disappears very rapidly after delivery and fetal nucleated cells remain longer in maternal circulation, and that there is no correlation between these two either before or after delivery.

Increased plasma mRNAs of placenta-specific 1 (PLAC1) and glial cells-missing 1 (GCM1) in mothers with pre-eclampsia.

In this study we have investigated whether quantitative analysis of placental mRNAs in maternal plasma provides a way to monitor placental status. We measured plasma concentrations of human chorionic gonadotropin beta-subunit (betahCG) and human placental lactogen (hPL) mRNAs as previously reported mRNAs and pregnancy associated plasma protein A (PAPP-A), placenta-specific 1 (PLAC1) and glial cells-missing 1 (GCM1) mRNAs, which have not been measured during the course of normal pregnancy. Firstly, peripheral blood was obtained at various times from healthy pregnant women to clarify the time course of placental mRNAs. Secondly, blood was obtained from women with pre-eclampsia and gestational age-matched controls to examine whether placental mRNAs change in pre-eclampsia. Plasma was separated from these samples for extraction of RNA, followed by reverse transcription polymerse chain reaction analysis. Median concentrations of PLAC1 and GCM1 mRNA in plasma of pre-eclamptic subjects respectively were 1625 and 2141 copies/ml, significantly higher than 195 and 881 copies/ml, the values for controls (Mann-Whitney test, p<0.001). No significant difference was seen in hPL, betahCG, or PAPP-A mRNA concentration between pre-eclamptic and control groups. Plasma PLAC1 and GCM1 mRNAs appear promising as noninvasively measurable molecular markers for pre-eclampsia.