Pregnancy belly button concave in general and the uterus enlargement after the local pressure in the abdomen increases or the fetus into the basin and so on related. 1. Increase in localized pressure in the abdomen. Women to the middle and late stages of pregnancy due to rapid fetal development, the uterus increases significantly will lead to abdominal size, and abdominal skin is pulled and abdominal pressure continues to increase, will cause changes in abdominal tension, the belly will be open, the belly button will also change. If the pregnant woman’s belly is more flaccid, it is easy to appear navel depression phenomenon, is normal. 2. Fetal pelvic. If the phenomenon of belly button depression occurs at the end of pregnancy, it may be due to fetal pelvic fetal descent, pregnant women’s belly loosened and caused. Pregnant women belly button concave in such as no discomfort symptoms, generally do not need special treatment, do a good job of pregnancy checkups can be.