The lap belt has a certain effect on the fetus, and this effect can be good or bad. The good thing is that it can protect the fetus and help maintain the normal fetal position, the bad thing is that if the lap band is too tight, it may restrict the growth of the fetus: a. Benefits 1, protect the fetus: the lap band can hold up the pregnant woman’s abdomen, relieve the pressure on the pregnant woman’s waist, make the pregnant woman’s back pain and pelvic pain caused by ligament elongation get better, provide help for the pregnant woman whose belly is bigger and heavier and who needs to hold her belly with her hands when walking, and protect the fetus; 2. 2.Maintain normal fetal position: after the fetal position is breech and the doctor does external inversion to head position, in order to prevent the fetal position from returning to the original breech position, the abdominal support belt can be used to restrict and help maintain the normal fetal position. Second, the disadvantages, especially after the middle of pregnancy, the fetal body grows rapidly, the volume increases more obviously, pregnant mothers use belly band during pregnancy, if the belly band is tied too tight, it will reduce the volume of the abdomen, resulting in increased intrauterine pressure, limiting the growth of the fetus. So when using the lap belt, pay attention to the appropriate elasticity, so that the lap belt is not too tight. In addition, avoid wearing too tight clothes, to loose, comfortable.