Cigarettes and old alcohol are not only the enemies of eugenics, but also one of the causes of infertility. According to a recent foreign study, smoking interferes with and destroys normal ovarian function, causing irregular menstruation, premature menopause and infertility. Even if women who smoke get pregnant, they are prone to miscarriage, premature labor and stillbirth, and the weight of the children they give birth to is much lighter than that of non-smokers. Due to the cigarette smoke contains strong teratogenic substances, so men who smoke will often make the sperm reduction, and a variety of deformed sperm, thus bringing the inability to give birth or give birth to children with congenital malformations of the consequences. The motherland medicine has long had “alcoholics more no after” said. Modern medicine reveals that excessive alcohol consumption can jeopardize the function of the reproductive system, leading to endocrine disorders and changes in the chromosome results and number of reproductive cells. In the semen of long-term drinkers, the number of spermatozoa decreases, activity is weakened, and the incidence of impotence, infertility and male feminization increases significantly. Alcohol also impedes the development and maturation of female eggs. As with smoking, chronic alcoholism can increase infertility and deformed babies. Therefore, for the happiness of the family and the health of the next generation, unmarried or married young men and women should not be addicted to alcohol and tobacco, so as not to jeopardize themselves and their offspring.