MicroRNAs in Combined Spent Culture Media and Sperm Are Associated with Embryo Quality and Pregnancy Outcome

Objective: To identify differentially abundant miRNAs in sperm samples and spent culture media (SCM) of embryos of different grade toward a prediction of pregnancy outcome.

Design: Array-based reverse-transcription quantitative polymerase chain reaction profiling and validation.

Setting: University research institute and in vitro fertilization center.

Patient(s): Couples (n = 61) undergoing infertility treatment with the use of intracytoplasmic sperm injection.

Interventions(s): None.

Main Outcome Measure(s): Abundance levels of miRNAs in combined SCM of embryos of different quality and in sperm samples associated with pregnancy outcome.

Result(s): Out of 372 screened miRNAs, miR-19b-3p and let-7a-5p were detected consistently in all SCM and sperm samples. The abundance levels of miRNAs were significantly altered between SCM of embryos with different quality (G1, G2, and G3 grades). Specifically, miR-320a and miR-15a-5p were differentially abundant in G1 vs. G2, miR-21-5p in G1 vs. G3, and miR-20a-5p in G2 vs. G3. The abundance levels of combined SCM and sperm derived miRNAs were also significantly altered between different pregnancy outcomes. MiR-19b-3p showed the highest area under the receiver operating characteristic curve values between positive and negative outcomes, with lower abundance levels in both combined SCM and sperm samples associated with a positive pregnancy outcome. MiR-320a, miR-15a-5p, miR-21-5p, and miR-20a-5p showed similar results in combined SCM samples.

Conclusion(s): miRNA abundance levels in combined SCM and sperm differed significantly depending on embryo quality and pregnancy outcome. MiR-19b-3p may serve as a potential biomarker to predict pregnancy outcome.