For pregnant women, it is important to urinate and empty the bladder before the puncture. During the puncture process, do not be overly nervous, relaxation is the best cooperation, the pain level of the puncture is similar to the usual pain of intramuscular injections, the more tense the abdominal muscles will feel the more pain, the doctor will do a good job of positioning before the puncture, generally will not cause harm to the fetus. After the puncture, you are forbidden to have sex for 2 weeks, you can rest properly, do not take a shower on the same day, and the dressing on the puncture point can be removed on the next day. If there is stomach pain, vaginal bleeding, vaginal fluid or fever should go to the emergency room in time. There are also some special groups of people, such as pregnant women with twin fetuses, who need to undergo separate puncture of the two fetuses, and the doctor will use a special method to distinguish between the amniotic fluid of the two fetuses; there are also pregnant women with a special blood type Rh-negative blood type, where the puncture procedure has the effect of increasing the exchange of blood between the fetus and the mother and increasing the risk of hemolysis in the newborn, and the need for injection of Rh immune globulin to carry out active immunity; and similarly in patients with active hepatitis B, the procedure may increase vertical transmission to the fetus. Similarly, in patients with active hepatitis B, the puncture may increase the risk of vertical transmission of the hepatitis B virus to the fetus, which also requires hepatitis B immunoglobulin injection. In addition, if there is a fever or an abnormally high white blood cell count prior to the puncture, the doctor may suspend or postpone the procedure to make sure there is no infection before performing the puncture.