The chances of a twin pregnancy with one blastocyst being transferred are very low and it is extremely unlikely that it will develop into a twin pregnancy. When one blastocyst is transferred, it usually develops into a single fetus. If you are considering a twin pregnancy you can transfer two blastocysts, the chances of a twin pregnancy are higher, and if both blastocysts successfully implant and develop, it becomes a twin pregnancy. Twin pregnancies carry a much higher risk of complications than single pregnancies, such as early miscarriage, preterm labor, twin transfusion syndrome, hypertensive disorders of pregnancy, etc. Multiple pregnancies are not advocated for the safety of the mother and child. After transplantation, you should follow the doctor’s instructions, pay attention to rest, and use progesterone and other drugs to maintain pregnancy; after 8 days of transplantation, you can draw blood to check the human chorionic gonadotropin, to see whether the pregnancy is successful or not. After transplantation, you need to follow the doctor’s instructions to go to the hospital for regular checkups, and if you feel unwell, you should seek medical advice and consult a specialist for guidance.