The reason why men who are preparing for pregnancy should not drink alcohol is because alcohol affects the quality and quantity of sperm, reduces the chances of conception, and may lead to fetal malformations and affect fetal development. Alcohol enters all organs of the body, and if alcohol is consumed during the preparatory period, it can induce sperm abnormalities, higher sperm deformities, and lower activity, which can lead to the inability to combine with the egg, or the inability to properly implant after the combination, thus lowering the likelihood of conception. Poor quality sperm may also cause a series of effects on the fetus, such as developmental delay and mental retardation. In the preparation stage, both men and women should quit smoking and alcohol 3 months in advance, and should go to the hospital for relevant examinations before pregnancy, eugenics and eugenic pregnancy, to ensure the birth of a healthy baby.