Pregnant belly button inside the dirty, smelly, often caused by the following factors: first, navel infection, navel long-term not wash will lead to the accumulation of more dander, dander will be mixed with the umbilical skin secretion of oil, longer time will cause infection, can be local drops of water or a small amount of sesame oil to remove the dirt, and then rub iodine povidone or Bactroban and other topical medications to anti-infective treatment; second, the patient has umbilical urachal cysts, which is the result of congenital umbilical and bladder channel is not closed. Second, the patient has umbilical ureteric cysts, which is caused by congenital unclosed umbilical and bladder channels, need to be regularly rechecked during pregnancy, postpartum can be localized to do imaging or cystoscopy, if it can be clear that the disease, need to be operated to get the root of the disease, during the period of treatment, can not eat too spicy food, such as chili peppers, spicy bars, etc., and at the same time, be careful not to wash the umbilicus excessively, in order to prevent the skin from breakage and infection.