Mini-detectorial examination is mainly a test to rule out fetal malformations, and usually does not need to be performed in a fasting state, so there is no need for fasting in the morning. Minor aberration examination, usually at about 20 weeks, although does not need to be in the fasting state, but first need to hold urine. The examination in the urine holding state, can be very good to show the position of the placenta, at the same time, can also observe the length of the cervix. If you need to carry out a mini-exam, it is recommended to make an appointment in advance, communicate with the doctor in advance to understand the content of the items that need to be examined, which need to be analyzed specifically. Generally after the third month of pregnancy, there is no need to fast for the examination. Pregnancy is a special time, if any uncomfortable symptoms occur during pregnancy, it is recommended to visit the hospital in time to understand the cause.