The size of the belly in the third trimester of pregnancy has a large individual differences, some pregnant women’s stomach and pre-pregnancy no obvious difference, some pregnant women’s stomach can be slightly bulging. In the third trimester of pregnancy, the fetus is basically developed, but the fetus is still very small, the pregnant woman’s uterus enlargement is not obvious. For relatively thin women, the appearance of the basic can not be seen to be pregnant, that is, not yet show pregnant. Relatively fat women, belly fat thicker, wearing tight clothes can be seen in the case of small abdomen slightly bulging. The third trimester of pregnancy is converted into pregnancy weeks is about 12 weeks of pregnancy, at this time the uterus slowly grows from the pelvis to the pelvic cavity outside the part. The gynecologist can feel the uterus 3-4 cm above the pubic symphysis by palpation, but the uterus does not yet appear to be protruding into the abdomen. An ultrasound is needed in the third trimester, when the uterus is already above the upper edge of the pubic symphysis, and the probe is able to see the uterus more clearly without having to hold in urine.