The presence of foam in urine can only be clarified as normal by routine urine examination. The root cause of foam in urine is due to the change of surface tension of urine. Eight months of pregnancy belongs to the late pregnancy period, the foamy urine may be physiological factors or pathological factors, if it is physiological factors, it is normal, if it is pathological factors, it is not normal. Physiological factors: physiological foamy urine occurs during pregnancy, mainly including reduced water consumption or increased sweat excretion, resulting in the concentration of urine, causing an increase in the concentration of electrolyte components in the urine, which increases the surface tension of the urine, forming foamy urine, which improves after drinking water, and at this time the routine urinalysis is normal. Pathological factors: 1. Proteinuria: If there is an increase in protein content in the urine during pregnancy, the surface tension of the urine increases significantly, resulting in foam in the urine, often accompanied by loss of appetite, nausea, vomiting and other uncomfortable symptoms, mostly seen in acute glomerulonephritis, nephrotic syndrome, hypertensive diseases, immune diseases, etc.; 2. Urinary tract infection: urinary tract infection occurs during pregnancy, the pathogens of infection, such as common The bacterial decomposition products will lead to increased surface tension of urine to form foamy urine, which may also be accompanied by urinary frequency, urinary urgency and other urinary discomfort symptoms; 3, urinary stones: due to the pressure of the uterus on the ureter of the bladder during pregnancy plus the weakening of ureteral peristalsis, it is easy to secondary ureteral stones, stone particles will also lead to increased surface tension of urine, the formation of urine foam, often accompanied by urinary frequency, urinary urgency, pain or hematuria; 4, Gestational diabetes: Gestational diabetes leads to increased sugar in the urine, which increases the surface tension of the urine, resulting in the formation of foamy urine. Most women in pregnancy do not have obvious symptoms of discomfort, i.e., drinking more, eating more, urinating more and weight loss is not obvious, and often need to test blood sugar to confirm the diagnosis. Therefore, foamy urine in the eighth month of pregnancy requires specific analysis of the cause, and if physiological factors are ruled out, the corresponding examination should be carried out at the hospital in a timely manner to clarify the specific cause and then actively treat the condition to avoid delay.