Increased Cell-free Fetal DNA in Plasma of Two Women with Invasive Placenta

Abstract

Invasive placenta, often involving placenta accreta, placenta increta, and placenta percreta, is a life-threatening complication of pregnancy characterized by invasion of placental villi into the underlying myometrium. Invasive placenta is usually diagnosed as a result of abnormalities encountered during removal of the placenta at delivery. Because of profuse hemorrhaging in the early postpartum period, blood transfusion or emergency hysterectomy is often required in patients with invasive placenta. Invasive placenta is also associated with high maternal morbidity and a high risk of mortality. Therefore, prenatal prediction of this disease would be of great clinical benefit. Recently, Lo et al. (1) discovered the presence of fetal DNA in maternal plasma. They developed a real-time quantitative PCR assay with which to measure the concentration of fetal DNA within maternal plasma. In addition, they analyzed the Y-chromosome-specific SRY sequence to quantify the number of genome equivalents per milliliter of plasma in women carrying male fetuses (2). Although cell-free fetal DNA is reported to increase in maternal plasma in cases of preterm delivery (3), preeclampsia (4)(5), and pregnancy with a trisomy 21 fetus (6), it is unclear where this fetal DNA originates. In the …