Purpose: The purpose was to investigate the association between embryonic development or implantation and the content of interleukin-6 and 10 (IL-6, IL-10) and tumor necrosis factor-α (TNF-α) in single-blastocyst conditioned medium (SBCM).
Methods: Thirty-eight SBCM samples (SBCMs) were collected from blastocysts with different morphological scores. IL-6, IL-10, and TNF-α concentration in 38 SBCMs was detected by Single Molecule Array and compared according to the blastocyst quality: top-quality (TQ) and non-top quality (NTQ), or blastulation time: day 5 (D5) and day 6 (D6). In another experiment, 61 SBCMs were collected from TQ blastocyst transplanted on D5, and IL-6 concentration in SBCM was compared based on whether embryos are implanted or not (implanted and non-implanted).
Results: In the first experiment, IL-6, IL-10, and TNF-α concentration was not significantly different between the TQ-SBCM and NTQ-SBCM. The D6-SBCM had a higher IL-6 concentration compared with the D5-SBCM, while IL-10 and TNF-α concentration was not significantly different between the D5-SBCM and D6-SBCM. The IL-6 concentration in D5-NTQ or D6-TQ SBCM was higher than that in D5-TQ or D6-NTQ SBCM (P < 0.05), respectively. Furthermore, the spearman analysis demonstrated that IL-6 concentration in SBCM was negatively correlated with the blastocyst quality on D5 and positively correlated with the blastocyst quality on D6. In the second experiment, no significant difference in IL-6 concentration was found between SBCM from implanted and non-implanted blastocyst.
Conclusion: IL-6 concentration in SBCM was associated with embryo quality depending on the blastulation time, although it might not be associated with the blastocyst implantation.
Keywords: Blastocyst quality; Interleukin-10; Interleukin-6; Single Molecule Array platform; Single-blastocyst conditioned medium; Tumor necrosis factor-α.