There are various reasons for stomach pain during pregnancy: 1. The symptoms of stomach pain in early pregnancy are mostly due to the increase in the size of the uterus causing smooth muscle pulling and stimulation of the nerves, which can lead to pulling pain. The gradual increase in the size of the uterus will also affect the uterine ligaments, leading to soreness in the lower abdomen of pregnant women, especially in the groin. 2. The gradual increase in the size of the uterus will slowly compress the stomach, which may lead to symptoms such as pressure in the upper abdomen, acid reflux and belching. At the same time, due to the weakening of gastrointestinal peristalsis, the muscle tension in the stomach increases more than before, which can easily cause the phenomenon of gastric contents reflux. The backflowing stomach contents, stimulating the mucous membrane of the esophagus will produce burning pain in the stomach area.3. If a pregnant woman suddenly feels severe pain in the abdomen, even accompanied by vaginal bleeding, this may be a symptom of pre-eclampsia miscarriage, which requires timely medical examination at a regular hospital for fetal preservation treatment.