Correlation of fetal DNA levels in maternal plasma with Doppler status in pathological pregnancies

OBJECTIVES: To evaluate whether intrauterine growth restriction (IUGR) as seen in preeclampsia is associated with high levels of fetal DNA in maternal circulation, and whether fetal DNA is related to altered uterine and/or umbilical artery Doppler velocimetry. METHODS: Fetal DNA quantification was performed by real-time PCR on SRY sequences in 64 male-bearing pregnant women with IUGR and/or preeclampsia and 89 controls. RESULTS: Fetal DNA content was significantly elevated in IUGR pregnancies similar to preeclampsia and correlated with altered umbilical Doppler velocimetry, while no correlation was found with uterine Doppler status. CONCLUSION: Increased fetal DNA levels in maternal plasma may be a sign of placental or fetal pathology even in the presence of normal uterine Doppler velocimetry, allowing a more precise diagnostic evaluation. The finding that elevated fetal DNA in IUGR pregnancies correlates with abnormal umbilical Doppler velocimetry suggests that fetal DNA release is associated more with fetal chronic hypoxia than with fetal size.