Urine protein itself has no significant adverse effects on pregnancy. However, the process of pregnancy can cause further aggravation of the primary disease of urine protein and some serious complications, which can affect the normal development of the fetus after pregnancy. The common causes of protein in the urine of women during pregnancy include combined hypertension during pregnancy, combined diabetes during pregnancy, combined nephrotic syndrome during pregnancy, and glomerulonephritis. It is also possible to have simple transient proteinuria. If proteinuria has been detected before pregnancy, further tests should be performed to clarify the specific cause of proteinuria before considering whether pregnancy is possible. When proteinuria is found after pregnancy, the cause should be identified and the primary disease should be actively treated to prevent further development of the condition.