Hydronephrosis is a problem that often occurs in pregnant women. Due to the special period of pregnancy, it is not possible to take drugs for therapeutic interventions, but only through their own adjustment. The causes of hydronephrosis in pregnant women include fetal compression, urinary obstruction, ureteral compression, and gynecological surgery before pregnancy, etc. The following methods are used to deal with the causes of hydronephrosis in the left kidney: 1. Pregnant women can rest in the right lateral position and avoid supine position to prevent pressure on the left side and reduce the discomfort caused by hydronephrosis. 2. 3, in pregnancy to carry out appropriate low-intensity exercise to prevent the formation of hydronephrosis. 4, in pregnancy, left hydronephrosis, most of them are not caused by disease, but by the abnormal condition of the body during pregnancy, as long as timely adjustment can be quickly returned to normal, and the symptoms of hydronephrosis will be gradually eliminated after delivery.