Before getting pregnant, from the perspective of eugenics, both men and women should undergo the necessary reproductive health checkups to screen out factors unfavorable to fertility as early as possible, and to treat diseases unsuitable for pregnancy as early as possible, so what homework should both men and women do? The homework for both men and women should include quitting smoking and drinking for 3-6 months before pregnancy preparation, moderate exercise, proper supplementation of folic acid and vitamins, strengthening nutrition, and less exposure to cell phones and computers. Special homework for the male partner includes semen quality tests, measurement of sex hormone levels, infection screening, routine blood and urine screening, and reproductive ultrasound. Semen tests are very important to provide current parameters of the sperm, and blood tests and ultrasound can clarify the cause in many patients with oligozoospermia and azoospermia. Chromosomal tests and Y chromosome tests for microdeletions of spermatogenic genes are also necessary for patients with severe oligozoospermia and azoospermia. For patients who have had previous recurrent miscarriages, testing for the integrity of the sperm genetic material is required. For the female partner, special homework should be done, including determination of ovarian reserve function, measurement of sex hormone levels, screening for viruses such as toxoplasmosis, cytomegalovirus, rubella virus, cytological examination of cervical smear, HPV screening, thyroid function tests, reproductive ultrasound, etc. For patients who have had recurrent miscarriages, special laboratory tests and examinations for chromosomes, rheumatism and immunity, coagulation, platelet aggregation rate, etc. are also required. In short, these pre-pregnancy homework is necessary, especially in the current haze and other serious environmental pollution, in order to the health of the next generation, couples of childbearing age should pay attention to the pre-birth health checkups, and do a good job of preparing for pregnancy.