The possible reasons for 80 days of pregnancy tummy ache are as follows: first, abnormal development of the fetus in the mother’s body, which is one of the most common causes of pregnancy tummy ache in pregnant women, such as the fetus in the mother’s body due to lack of oxygen fetal movement accelerates, which will stimulate the mother’s body through nerve conduction, thus making the mother feel tummy ache; second, the position of the fetus in the mother’s body has changed, which will also indirectly cause tummy ache in the mother’s body. Third, the mother may have some diseases, such as appendicitis, intussusception, intestinal torsion, which can suddenly cause stomach pain in pregnant women, which is also very common in pregnant women; fourth, women may suffer from gynecological diseases, such as whether women suffer from pelvic inflammatory disease, endometritis, which can also involve the abdomen and cause the said stomach pain; fifth, whether the pregnant woman has had a miscarriage before. If the pregnant woman has a history of miscarriage, then the stomach pain again may also be a sign of miscarriage. All of these situations are very common and are common causes of stomach pains during pregnancy for women.