Pregnant women can do paternity testing, which requires the genetic information of the baby, that is to say, to obtain the DNA of the baby. During pregnancy, if it is early pregnancy, villi should be extracted to obtain DNA. In the second and third trimester of pregnancy, fetal DNA information can be obtained by extracting amniotic fluid or umbilical cord blood. However, any way to obtain the genetic information of babies has certain risks, which may lead to miscarriage and premature delivery, and may also induce infection. Therefore, we must communicate with the doctor carefully before making sure to do the examination, make clear the related risks and complications, and then arrange the specific examination time after careful decision. There is still a waiting time to obtain these genetic data, because it needs to be cultivated and analyzed by relevant laboratory means before a report with clear value can be produced.