Usually, after 12 weeks of pregnancy, women’s belly will begin to grow, but there are individual differences, pregnant women’s body type, amniotic fluid, placenta position and other factors will affect the time and belly size. 1, pregnant women’s body type: the size of the pregnant belly and pregnant women’s body type, if the pregnant women’s body type is thin, low abdominal wall fat content, the belly may become larger later, some pregnant women to the time of birth pregnant belly is still not The size of the belly is not obvious. Some pregnant women have a fat body type and more fat on the abdominal wall, which makes it easy for them to have a big belly and move around earlier; 2, the amount of amniotic fluid: because of the different body types of pregnant women, the amount of amniotic fluid will also vary. If the amniotic fluid is more, the uterus will be larger, appearing pregnant women’s belly will be larger. If the amniotic fluid is relatively small, the pregnant woman’s stomach is relatively small; 3, placenta position: if it is the front wall placenta, it may be easy to show pregnancy, that is, earlier to show a large stomach. If the placenta is posterior, it may show pregnancy slightly later; 4, pelvic bone size: if the pregnant woman’s pelvis is wide, the fetus has enough space to grow, the pregnant woman’s stomach is relatively less pregnant. If the pregnant woman’s pelvis is narrower, it will be easier to show pregnancy, the belly will be slightly earlier; 5, the number of fetuses: if it is a double or even multiple, it will show pregnancy earlier than a single child, and the pregnant woman’s belly will be bigger earlier.