Granulocyte-Macrophage Colony Stimulating Factor in Single Blastocyst Conditioned Medium as a Biomarker for Predicting Implantation Outcome of Embryo

Abstract

Background: It is highly desirable to develop new strategies based on secretomics to more accurately selection of embryos with the highest developmental potential for transfer. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been reported to promote embryo development and pregnancy establishment. However, the predictive value of GM-CSF in single blastocyst selection remains unclear. This study is to determine the concentration of GM-CSF in human single-blastocyst conditioned medium (SBCM) and to evaluate its association with embryo quality and pregnancy outcome.

Methods: The patients with ≤38 years of age receiving the first cycle of assisted reproductive therapy were included in this study. The patients who had <4 top-quality embryos formed by the fertilized two pronuclear zygotes on day 3 were excluded. A total of 126 SBCM samples (SBCMs) were included, of which blastocysts from 77 SBCMs were later transferred in subsequent frozen-thawed embryo transfer. The concentrations of GM-CSF were detected by single-molecule array (SIMOA) and analyzed for their possible association with embryo quality and pregnancy outcomes. The top-quality embryo (TQ), positive HCG (HP), clinical pregnancy (CP), and ongoing pregnancy (OP) rates were determined and compared between groups divided based on GM-CSF concentrations.

Results: The detection rate of GM-CSF was found to be 50% in all SBCMs. There were significant differences in TQ rate, HP rate, CP rate and OP rate among high concentration group, medium concentration group and low concentration group. Both GM-CSF alone or GM-CSF combined with the morphological score (MS) had a greater AUC of ROC curve than that of MS alone to predict the pregnancy outcome, and GM-CSF combined with MS had the highest AUC.

Conclusions: The concentration of GM-CSF in SBCM was detected at fg/ml levels, which was associated with embryo quality and pregnancy outcome. Collectively, GM-CSF may be used as a biomarker for prediction of pregnancy outcome and selection of embryos with high developmental potential for transfer in assisted reproductive technology (ART).

Keywords: embryo quality; granulocyte-macrophage colony-stimulating factor; pregnancy outcome; single-blastocyst conditioned medium; trace protein detection.

Figure 1

Receiver operating characteristic curve analyses of GM-CSF alone (Blue line), morphological score (MS) alone (green line), and morphological score combined with GM-CSF (yellow line) for predicting pregnancy outcomes at different gestation periods including HCG positive (A); clinical pregnancy (B); ongoing pregnancy (C). AUC_a and P _a for GM-CSF, AUC_b and P _b for MS, and AUC_c and P _c for combined indicator. ^* p < 0.05; ^** p < 0.010; ^*** p < 0.001.