Hemolysis, Elevated Liver Enzymes, and Low Platelet Count (HELLP) Syndrome as a Complication of Preeclampsia in Pregnant Women Increases the Amount of Cell-free Fetal and Maternal DNA in Maternal Plasma and Serum

Abstract

Fetal DNA in plasma and serum of pregnant women has been reported to be significantly increased in preeclampsia (1)(2). This increase may even precede clinical diagnosis (3). We hypothesized that subsequent development of hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome will further increase fetal DNA in maternal plasma and serum. In addition, total cell-free DNA may be increased in plasma as a result of tissue destruction, which generally occurs in HELLP syndrome. To confirm our hypothesis, we recruited three groups of pregnant women with informed consent and matched for maternal age [(MA), in years] and gestational age [(GA), in weeks+days] at the time of blood drawing; the median ages (and ranges) were as follows: normotensive women (n = 10), MA, 30 (24–37) and GA, 32+6 (27+0−34+3); preeclamptic women without HELLP syndrome (n = 7), MA, 28 (24–36) and GA, 33+0 (27+6−34+3); and preeclamptic women with HELLP syndrome (n = 10), MA, 31 (26–38) and GA, 26+6−33+6. All women in the latter group had HELLP syndrome at the time of the blood drawing, except two who developed HELLP only after delivery. All participants were carrying single male fetuses. Preeclampsia was defined as a diastolic blood pressure >90 mmHg on two or more consecutive occasions after 20 weeks of pregnancy in previously normotensive women, with proteinuria >0.3 g/L in a 24-h collection period. HELLP syndrome was defined as the simultaneous occurrence of hemolysis (lactate dehydrogenase, >600 U/L), increased liver enzymes (serum aspartate aminotransferase and alanine aminotransferase >70 U/L), and low platelets (<100 × 109/L) (4). Diastolic blood pressure [median (ranges) in mmHg] was 70 (60–80), 120 (110–130), and 118 (110–140) for women with normotensive and preeclamptic pregnancies without and with HELLP …