Lower abdominal distension and pain in early pregnancy is a common symptom. Generally, the causes of lower abdominal distension and pain that occur during early pregnancy are the following: first, normal uterine dilation, because after pregnancy the gestational sac expands and the uterus becomes engorged with blood, so the smooth muscle of the uterus is more sensitive to the reaction brought by the expansion of the gestational sac and the expansion of the uterus, causing lower abdominal distension and pain. Secondly, it is a manifestation of uterine cramps, which may also be one of the symptoms of preterm abortion, so continue to observe. Thirdly, it is related to exertion or diet. The intake of too much food containing arachidonic acid, including shrimp, crab or raw and cold food, leads to uterine contraction, which can also produce lower abdominal distension and pain. When lower abdominal distension and pain occurs during early pregnancy, it is important to determine whether it is a preterm abortion based on the HCG measurement and ultrasound examination of hormone levels such as progesterone and estrogen. Normally, lower abdominal distension and pain of varying degrees will occur during early pregnancy and does not need to be treated.