The excessive urination at 38 weeks of pregnancy may be a sign of impending labor, which is caused by the enlarged uterus and the fetal head entering the pelvis to compress the bladder. If it is accompanied by regular contractions and a feeling of soreness and swelling in the lower abdomen, it may indicate impending labor. However, it may also be related to increased metabolites, gestational diabetes, urinary tract infections, etc. Therefore, specific analysis of specific problems is needed: a. Prolific labor: At 38 weeks of pregnancy, most of the fetal head is in the pelvis, which increases the pressure on the bladder and leads to a sharp decrease in the effective capacity of the bladder, and then the symptoms of frequent and excessive urination. If the pregnant woman not only urinates a lot, but also has irregular contractions, the feeling of fetal descent, redness and other symptoms, it means that labor is imminent and she should be hospitalized in time for delivery. Second, non-labor: 1, metabolites increase: 38 weeks of pregnancy, the mother’s metabolites increase, at the same time, the growth of the fetus at this stage will also produce metabolites, these metabolites need to be discharged from the mother, which can lead to an increase in the amount of pregnant women urine. This is a normal physiological phenomenon, pregnant women should pay attention to drink more water to replenish water, so as to avoid dehydration; 2, gestational diabetes: if pregnant women combined with gestational diabetes, there will also be more urine, so you need to monitor the blood sugar situation. If there is abnormal blood sugar, you need to go to the nutrition clinic for dietary guidance, control blood sugar and avoid eating foods with high sugar or calories; 3. Urinary system infection: the placenta secretes a lot of estrogen that can make the muscle layer of the ureter, renal pelvis, renal calyces and bladder proliferate and thicken. Progesterone can make the smooth muscle of the ureter relax and peristalsis weaken, making the bladder less sensitive to tension, which leads to overfilling or incomplete urination, creating conditions for bacteria to multiply in the urinary system, which in turn leads to frequent and excessive urination. Pregnant women are advised to visit a hospital to further improve routine urine examination and exclude any other organic pathology.