The Expression of microRNAs and Their Involvement in Recurrent Pregnancy Loss

Abstract

Background: Recurrent pregnancy loss refers to the spontaneous demise of two or more pregnancies before the 24 weeks of gestation. In almost half of the cases of recurrent miscarriages, the causes remain unknown since there is no reliable way of prognosis, early diagnosis, or treatment. Recent research has detected differential expression of certain miRNAs in reproductive system pathologies. Methods: The aim of the present review is to focus on microRNAs and their relationship with idiopathic recurrent miscarriages and to correlate miRNA expression with recurrent miscarriage and examine their potential role as biomarkers. Pubmed/Medline and Scopus databases were searched up to 31st January 2024 with terms related to recurrent pregnancy loss and miRNAs. Results: In total, 21 studies were selected for the review. A total of 75 different miRNAs were identified, showing a statistically significant differential expression. Around 40 miRNAs had increased expression, such as miR-520, miR-184 and miR-100-5p, 21 decreased, such as let-7c, and 14 had either increased or decreased expression depending on the study, such as miR-21. Conclusions: The dysregulation of miRNA expression is strongly associated with recurrent miscarriages. The circulating in the peripheral blood miRNAs, miR-100-5p and let-7c, might be utilized as biomarkers and establish a valuable non-invasive prognostic and diagnostic tool in the future.

Exploring Differentially Expressed Sperm miRNAs in Idiopathic Recurrent Pregnancy Loss and Their Association with Early Embryonic Development

“…MicroRNAs (miRNAs) are endogenous non-coding small RNA molecules, about 22 nucleotides in length, that regulate more than 60% of protein-coding human RNA by either regulating gene expression or degrading mRNA. MiRNAs play a crucial role in various regulatory biological processes, and alterations in their expression are linked to the development of many diseases, including RPL [ 19 , 20 ]. Several recent studies have reported the differential expression of specific miRNAs in RPL [ 21 , 22 , 23 , 24 , 25 ].…”

“…Several recent studies have reported the differential expression of specific miRNAs in RPL [ 21 , 22 , 23 , 24 , 25 ]. A systematic review of 21 studies by Patronia et al identified 75 statistically significant differentially expressed miRNAs (DEMs) in women affected by RPL, including miR-184, miR-520, miR-155/-5p, miR-100-5p, miR-146a/-5p, miR-21, miR-23a-3p, miR-92a/-3p, and miR-221-3p [ 19 ]. However, no comprehensive research has been conducted on paternal miRNAs in this context.…”