Amniocentesis examination is usually not will not stab the fetus. 1. Amniotic fluid protection: Pregnant women undergo amniocentesis, usually around 18 weeks of pregnancy, when the amount of amniotic fluid in the uterine cavity has already proliferated to a certain level, and the amniotic fluid is relatively large, which can provide better protection for the fetus. 2. Ultrasound monitoring: When pregnant women receive amniocentesis examination, it is usually performed under ultrasound monitoring, which can directly observe the activity of the fetus, and then choose the place where amniotic fluid is more abundant, which can avoid the emergence of fetal limbs to extract amniotic fluid. If the fetus is in an active state, the puncture needle can be removed at any time to avoid harming the fetus. In addition, amniocentesis is an invasive test, so pregnant women are advised to choose a regular hospital.