The quality of the embryo is determined by the quality of the egg and sperm, and the conditions in the IVF laboratory. 1. Egg and Sperm Quality: Embryo is developed by fertilization of egg and sperm, and the quality of embryo is determined by the quality of egg and sperm together. The quality of the embryo is determined by the quality of both the egg and the sperm. Therefore, the quality of the embryo is directly affected by the quality of the egg and the sperm. As we age, the quality of female eggs and male sperm will deteriorate, as well as the quality of female eggs will deteriorate as a result of reduced ovarian function. Men who work under pressure, smoke and drink for a long time, have irregular work and rest, or are genetically predisposed to poor sperm quality will affect the quality of the embryo. In addition, certain endocrine diseases and autoimmune diseases can also affect the quality of eggs and sperm. 2. Conditions of IVF laboratory: If you choose in vitro assisted reproduction technology, the quality of embryos is also determined by the laboratory conditions. If the technicians are not professional enough and the laboratory conditions are not good enough, even the best fertilized eggs will be affected before transfer. It is recommended that couples who choose to conceive naturally should try to choose the optimal age to conceive, in addition to maintaining good lifestyle habits and treating other diseases that affect fertility; couples choosing assisted reproduction should go to a professional reproduction center for consultation. If there is any discomfort during the preparation for pregnancy, consult a professional doctor for treatment.