The pain at the bottom of the small abdomen at 33 weeks of pregnancy may be due to physiological factors, or may be due to pathological factors such as preterm labor, the causes of different treatment options are different: a. Physiological factors: due to the growth and development of the fetus, the uterus will be propped up, the uterus continues to grow and gradually sag, will pull the muscles of the uterus and the surrounding ligaments, pregnant women will have the symptoms of pain at the bottom of the small abdomen, this belongs to physiological abdominal pain, no special This is physiological abdominal pain, no special treatment, appropriate bed rest can be relieved. Pathological factors: 1, premature labor: If the pain at the bottom of the small abdomen of pregnant women is persistent pain, and the pain is more and more intense, accompanied by vaginal bleeding, water and other symptoms, may be premature labor, should promptly consult a doctor; 2, preterm labor: If the pain at the bottom of the small abdomen of pregnant women accompanied by vaginal bleeding symptoms, may be caused by preterm labor, should promptly consult a doctor for fetal preservation treatment; 3, digestive system diseases. If a pregnant woman with pain at the bottom of the small abdomen at the same time appear diarrhea, constipation and other symptoms, should carry out the corresponding examination, for enteritis, gastroenteritis, appendicitis and other diseases for targeted treatment; 4, other: there are also pregnant women themselves have comorbidities or trauma, and the pain at the bottom of the small abdomen, should promptly seek medical treatment.