Clinical Value of Follicular Fluid MicroRNA-21 and MicroRNA-126 Expression Profiles in Predicting Oocyte Competence and Live Birth Success

Background Predicting the success of In Vitro Fertilization (IVF) and Intracytoplasmic Sperm Injection (ICSI) cycles remains a challenge. Current morphological grading systems are subjective and do not always reflect the genetic or epigenetic potential of the embryo. This study investigates whether the expression levels of miRNA-21 and miRNA-126 in follicular fluid (FF) can serve as non-invasive molecular biomarkers for predicting live birth outcomes. Methods A prospective study was conducted with 81 patients undergoing IVF/ICSI treatment. Follicular fluid samples were collected during oocyte retrieval. The expression levels of miRNA-21 and miRNA-126 were measured using quantitative real-time PCR (qRT-PCR). To address the small sample size and potential bias in live birth outcomes, Firth’s Penalized Likelihood Logistic Regression analysis was performed. Models were adjusted for maternal age and Body Mass Index (BMI). Results FF expression levels of both miRNA-21 (p = 0.034) and miRNA-126 (p = 0.038) were significantly higher in cycles that resulted in a live birth compared to those that did not. After adjusting for maternal age and BMI, both miRNAs remained independent predictors of live birth. A combined predictive model utilizing both miRNAs demonstrated an Adjusted Area Under the Curve (AUC) of 0.742, indicating a strong discriminative ability. Conclusions Increased levels of miRNA-21 and miRNA-126 in follicular fluid are associated with higher live birth rates. These microRNAs represent promising, non-invasive "liquid biopsy" biomarkers for assessing oocyte competence and predicting the clinical success of ART cycles