The success rate of 4BC blastocysts is average, the success rate is about 40%. 4BC blastocysts are not high quality blastocysts, but they can meet the transfer conditions, normally the higher the blastocyst grade the higher the transfer success rate. It is better to choose good quality blastocysts for transfer to increase the success rate. 4BC blastocysts have a higher survival rate after successful transfer, and it is better to go to a regular large hospital for embryo transfer to also increase the success rate. Before embryo transfer, you need to go to the hospital for medical examination to see how your condition is. If your body resistance is low and endometrial development is not good, it will cause embryo transfer failure, you can improve your body resistance reasonably under the guidance of your doctor. After embryo transfer, pay attention to rest, adopt a healthy lifestyle, do not engage in strenuous activities, and preferably eat more food with high protein content.