From the perspective of eugenics, 25-34 years of age is the best time to get pregnant, the risk of complications is lower, but how long after marriage to have children in the clinic does not have a unified standard, but also combined with their own age of marriage, physical condition, economic conditions and other comprehensive judgment to start the preparation for pregnancy plan. The vast majority of newlyweds have a normal sex life and do not use any contraceptive measures, and will get pregnant within six months. If a newlywed couple has a plan to have children, they need to do a good job of preparing for pregnancy. 1, physical preparation: couples need to at least three months in advance to develop good habits, early to bed and early to rise, do not stay up late to ensure adequate rest and sleep; quit smoking and drinking. Pay attention to a balanced diet, eat more fresh vegetables and fruits, and supplement enough folic acid and calcium. At the same time should be prohibited from exposure to harmful stimuli, as little as possible application of drugs; 2, spiritual preparation: couples maintain a happy mood to conceive, do not have a psychological burden, let nature take its course, while learning the relevant knowledge of pregnancy; 3, pre-pregnancy examination: both spouses should be subjected to the basic pre-pregnancy examination, such as both sides need to carry out eugenics four, hereditary diseases, infectious diseases and other tests. The male side of the routine semen examination, the female side including reproductive system examination, gynecological endocrine examination. Precautions The risk of complications for pregnant women increases with age, so it is recommended to weigh all types of factors and choose the most appropriate time to prepare for pregnancy, and not to take vaccinations during the preparation period.