The necessary items of preconception examination are mainly the following: first, basic blood tests, such as blood routine, blood sugar, thyroid function, eugenics five items, infectious disease examination, etc. Secondly, the examination of female hormone level. Third, gynecological examination and white belt examination. Fourthly, ultrasound examination. Ultrasound is mainly to check whether there are any special diseases in the uterus and both adnexa, and also to monitor ovulation through ultrasound. Fifth, examination of tubal patency, mainly tubal aspiration and tubal imaging, which are very important because infertility can easily occur in case of tubal incompetence, and chromosomal examination and five tests of infertility can be done for special women.