The success rate of 4cb blastocysts for implantation is usually between 50% and 70%, while 4cb blastocysts are not among the highest quality blastocysts, but after successful culture, the success rate of implantation is usually above 50%, and after implantation, healthy embryos can develop and grow normally. However, because of the difference in implantation in each individual, the implantation rate of 4cb blastocysts after transfer is below 50%, usually due to early or delayed implantation, so the implantation rate of 4cb blastocysts in these patients is relatively low, usually around 30%, but most of the patients who undergo blastocyst transfer will have implantation around day 2.