Patient question: disease: seven and a half months pregnant baby hydronephrosis reached 21mm seven months pregnant baby hydronephrosis 21mm description: five and a half months pregnant baby left hydronephrosis 7.3mm. baby left hydronephrosis pregnancy 32 cycles is 21mm ugh how to do ah five months pregnant baby left hydronephrosis 7.3mm six months is 10mm, seven months is 13mm to yesterday rose to 21mm Hope to help: Please give me some advice on treatment and whether my current condition requires surgery. The fetal medicine department of Shanghai First Maternal and Child Health Hospital Sun Luming Hospital Department: Changzhou Maternal and Child Health Hospital Obstetrics Department Provincial Maternal and Child Health Hospital Changzhou Second Hospital Obstetrics Department Shanghai First Maternal and Child Health Hospital Prenatal Diagnostic Center Sun Luming Reply: According to the ultrasound results, the fetus is considered to have hydronephrosis in the left kidney, and the fetal chromosome examination is recommended. If the chromosome is normal, most of the cases are due to congenital obstruction of the ureteral junction of the renal pelvis. It is recommended to follow up with ultrasound every 2-4 weeks during pregnancy to monitor the hydronephrosis and the condition of amniotic fluid. The timing of delivery depends on the presence or absence of obstetric indications, and the mode of delivery can be vaginal. Ultrasound is repeated 3-7 days after birth and the newborn is followed up by a pediatric urologist.