Tobacco contains a large number of toxic substances such as nicotine, hydrocyanic acid, ammonia, carbon monoxide, carbon dioxide, pyridine, aromatic compounds and tar. Smoking can affect fertility in both men and women. Some studies have shown that heavy smoking in men can lead to an increase in white blood cells in the semen, an increase in sperm malformations, and premature symptoms of sexual hypogonadism. In women, smoking can affect the menstrual cycle and the function of the ovaries, leading to premature ovarian decline. Recent studies have also shown that women who smoke are more likely to have miscarriages, premature births and stillbirths than women who do not smoke. Pregnant women who smoke are more harmful because the toxic substances in tobacco can be absorbed into the mother’s bloodstream with the smoke, which reduces the blood oxygen level in the mother’s body and can cause growth retardation in the fetus due to lack of oxygen. Pregnant women who smoke can increase the incidence of congenital malformations of the fetus, some data show that the number of congenital malformations born to mothers who smoke is 2.3 times higher than that of non-smoking mothers, smoking leads to anencephaly, cleft palate, cleft lip, dementia and physical developmental disorders of the fetus is 2.5 times higher than that of non-smokers. The survey also found that smoking during pregnancy impairs the fertility of their daughters as adults, affects nerve cells in the fetal cochlea, and can lead to fetal hearing impairment. A large survey conducted by Danish researchers confirmed that 30 to 40 percent of sudden infant deaths were linked to their mothers’ smoking during pregnancy. Smoking does more harm than good. Stay away from tobacco and stay away from disease! For men and women of childbearing age who have previously smoked, it is recommended that they start quitting 3 months before they are ready to have a baby, as this will help them to have a healthy baby.