Association between Selected Maternal Plasma Micro-RNAs and Idiopathic Recurrent Pregnancy Loss

Abstract

MicroRNAs are small noncoding RNAs that function to control gene expression. Recurrent pregnancy loss (RPL) is two or more consecutive pregnancy losses before 20 weeks of gestation. The aim of this study is to explore the expression level of a group of pregnancy-associated miRNAs in maternal plasma in normal pregnancy and RPL cases. We conducted a case control study on 100 Palestinian women: 60 patients with at least two unexplained consecutive pregnancy losses half of them were pregnant at the first trimester and the rest were non-pregnant and 40 healthy controls with at least two live births and no history of pregnancy loss; half of them were at their first trimester of pregnancy and the rest were non-pregnant. We investigated the relative expression of miR-21, miR-126, miR-155, miR-182, miR-222 and miR-517* using quantitative real-time polymerase chain reaction and Ct method experiments. Differential expression was evaluated using Student t test and fold change analyses. Only the expression difference of miR-21, miR-126 and miR-182 between patients and controls in the pregnant group showed statistically significant difference (p-value ≤ 0.05 ) with fold decrease of 1.5, .1.6 and 5.6, respectively. In non-pregnant group miR-21, miR-126, miR-222 and miR-517* expression were significantly different with fold decrease of 2.4, 2.9, 2.7 and 11.8, respectively. So miR-21 and miR-126 proved to be the most important microRNAs in idiopathic RPL as their level was significantly decreased in patients before being pregnant and during pregnancy.