Objective: The aim of the present study is to evaluate the plasma total cell-free DNA and cell-free fetal DNA level in maternal venous samples obtained from pre-eclamptic pregnant women during the third trimester (gestational age>28 weeks) and whether it shows a correlation with uteroplacental blood flow.
Materials and methods: This was a case–control study in which plasma total cell-free DNA, cell-free fetal DNA levels, and uteroplacental blood flow including umbilical artery resistance index, uterine artery resistance index and pulsitility index, and middle cerebral artery/umbilical artery pulsitility index were measured in 60 women diagnosed with pre-eclampsia, representing the study group, and another 60 normotensives were taken as controls. Both total cell-free DNA and cell-free fetal DNA were quantified by real-time PCR using the RASSF1A gene before and after treatment by methylation-sensitive restriction enzyme, respectively, irrespective of the sex of the fetus.
Results: Our results showed that there was a positive correlation between plasma cell-free fetal DNA, total cell-free DNA, and uteroplacental blood flow in pre-eclamptic women (P<0.05). To detect pre-eclampsia, the best cut-off value for plasma cell-free fetal DNA level was 80 copies/ml and that for plasma total cell-free DNA level was 137 copies/ml.
Conclusion: Our results found that there was a positive correlation between plasma cell-free fetal DNA level and the severity of pre-eclampsia. In addition, we found a correlation between plasma cell-free fetal, total cell-free DNA level, and uteroplacental blood flow in pre-eclamptic women during the third trimester.