Cell-free fetal DNA in the plasma of pregnant women with severe fetal growth restriction

OBJECTIVE: Although there have been reports of increased fetal nucleated erythrocytes in the blood of pregnant women who are carrying growth-restricted fetuses, there have been no reports of quantification of fetal DNA concentration in the plasma of women with fetal growth restriction. We quantified fetal DNA concentration in the plasma of pregnant women with preeclampsia and/or fetal growth restriction. STUDY DESIGN: We examined maternal plasma from 9 pregnant women with fetal growth restriction and 9 with preeclampsia and from 20 women who were gestational age-matched normal control subjects. All women carried a male fetus. DNA was extracted from 1.5-mL plasma samples, and the DYS14 and beta-globin gene were analyzed by real-time quantitative polymerase chain reaction. RESULTS: The concentration of fetal DNA was significantly higher in subjects with preeclampsia than in fetal growth restriction subjects and normal control subjects. Fetal DNA concentrations in fetal growth restriction subjects were similar to those of normal control subjects. The concentration of total DNA (beta-globin) was significantly higher in subjects with preeclampsia when compared with healthy control subjects. CONCLUSION: We demonstrated that there was no increase in fetal DNA in the plasma of pregnant women with fetal growth restriction and that most fetal DNA in maternal plasma originates from trophoblasts.