Many couples in a hurry to have children in order to “target”, “save strength”, usually have been abstinence, only in the ovulation period when intercourse. This approach seems very “sensible”, but in fact it is not advisable. The sperm will enter the epididymis, and before it reaches the end of the epididymis, about half of the sperm will age, decompose and be absorbed, even if the sperm finally comes to the best place for storage and maturation, its vitality is limited. If men do not have sex for a long time, the sperm will lose vitality and eventually disintegrate in the vas deferens, and the proportion of aging sperm will continue to expand. Therefore, if a man is abstinent for a long time, the first few ejaculations of semen will contain more aging sperm, not easy for his wife to conceive, and even if he can conceive, the low quality sperm will easily cause fetal mental retardation, deformities, or lead to miscarriage. This shows that abstinence does not improve the quality of sperm, if you want to achieve the purpose of eugenics through abstinence, it is obviously not feasible.