It is best to have preconception checkups 3-6 months before pregnancy because there is a certain amount of time for treatment and monitoring when the disease is detected through preconception checkups, and pregnancy can only occur after the condition is completely cured or stabilized. For example, if you have diabetes, hypertension, etc., you need to take reasonable medication to regulate your condition, and it is also recommended to monitor your condition regularly to see how stable it is. Rubella antibody test is also required during pregnancy checkup, if there is no rubella antibody, you need to get vaccinated, you cannot get pregnant within one month after vaccination, it is better to get pregnant 3-6 months after vaccination. Folic acid should be taken during the first trimester to prevent fetal neural tube abnormalities. If you have hypothyroidism or hyperthyroidism, you need to get reasonable treatment. If you have hypothyroidism or hyperthyroidism, it will easily affect your baby’s development and cause fetal mental retardation, so it is best to have a blood test for thyroid hormone about six months before pregnancy.