RESUMEN
Non-invasive methods are normally preferred to conventional invasive methods when selecting suitable embryos to improve pregnancy rates after assisted reproduction techniques. One of the most recognized non-invasive methods is to examine the supernatants of embryo culture media. Soluble human leukocyte antigen, class I, G (sHLA-G) antigen is a non-classical class I molecule that has been widely considered as a marker of pregnancy failure or implantation success. In the current study of some Iranian patients, we examined the concentration of sHLA-G at different time points after intracytoplasmic sperm injection and compared the rates to the morphology and quality of the selected embryos. We showed that the concentration of sHLA-G increases over time in high-quality embryos. We conclude that there is a positive relationship between morphology, quality, and sHLA-G concentration. We suggest that this relationship can be used to increase the chance of a successful pregnancy.