If you have a stomachache in the middle of pregnancy, there may be the following reasons: 1. Pre-eclampsia, this kind of stomachache is usually paroxysmal, burst of pain, and may be accompanied by vaginal bleeding, which must be paid great attention. 2. It may be caused by some other diseases, such as abdominal acute gastroenteritis, inflammatory diseases of the intestinal tract, such as Crohn’s disease, ulcerative colitis. 3. 4. some gynecological diseases, such as adnexitis, torsion of ovarian cysts and so on. If you have stomach pain in the middle of pregnancy, you should pay attention to it and go to a specialist hospital in time to improve the relevant examination and give timely and effective symptomatic treatment after a clear diagnosis.