The fetus in the third trimester of pregnancy is located in the woman’s pelvis, which corresponds to the lower abdomen, commonly known as the small belly. However, due to the small size of the fetus and the small amount of amniotic fluid in the uterus, the pregnant woman is not able to feel the uterus and the fetus on her belly. At this time, the fetus is already taking on a human form, the limbs can move, the fetus is about 9cm long, the biparietal diameter is about 1.9-2.2cm, the femoral length is about 0.6-0.7cm, and all organs are starting to work, such as the liver is gradually developing, the gallbladder can produce bile, and the kidneys can produce urine to the bladder. Pregnant women can observe obvious fetal movement through ultrasound, but they cannot feel it directly. As the fetus is about to enter the middle of pregnancy, it will gradually accelerate its development. Therefore, pregnant women should pay attention to timely calcium supplementation to prevent calcium deficiency in pregnant women from causing night cramps and affecting their sleep. In addition, you should also supplement protein, vitamins and dietary fiber and other nutrients to prevent constipation that may further lead to miscarriage.