Increased free fetal DNA levels in early pregnancy plasma of women who subsequently develop preeclampsia and intrauterine growth restriction

Abstract

Objective To determine if maternal plasma ffDNA is increased early in pregnancies which subsequently develop preeclampsia (PE) and intrauterine growth restriction (IUGR). Methods Blood was obtained at 11–14 weeks and plasma stored. Among those who delivered a male infant and had a birth weight under the tenth centile and/or PE, we divided them into those who delivered before 35 weeks (9) and those who delivered after this gestation (15). A third group with uncomplicated pregnancies was used as controls (24). Real time-polymerase chain reaction (RT-PCR) was carried out to detect the multi-copy Y chromosome associated DSY14 gene. Results There were no differences between the ffDNA levels in the group delivered after 35 weeks and the control group (2.23ge/mL–1.61ge/mL p = 0.39). However, the levels of ffDNA at 11–14 weeks were statistically, significantly higher in patients that delivered before 35 weeks (4.34ge/mL–1.61ge/mL p = 0.0018). A logistic regression analysis shows that for every unit (1ge/mL) in which ffDNA increases, the likelihood of having PE or a fetus growing under the tenth centile delivered before 35 weeks increases by 1.67 times (CI 1.13–2.47). Conclusion The concentration of ffDNA is significantly higher even during early pregnancy, in patients who subsequently develop PE and/or IUGR and are delivered before 35 weeks. Copyright  2009 John Wiley & Sons, Ltd. KEY WORDS: preeclampsia; maternal disease; placental disease; DNA; fetal Cells; nucleic acids and proteins; maternal serum Screening; fetal and placental pathology.