Normal values for fetal bladder size

There is no normal reference value for fetal bladder size, because under normal circumstances, the fetal bladder will be filled and emptied every 20-45 minutes, so the bladder size is not fixed.

Under normal circumstances, the formation of the fetal bladder can be seen under B-ultrasound examination at about 13 weeks of pregnancy, and the fetal bladder can be clearly observed at about 15 weeks. If there is anechoic urine in the bladder during B-ultrasound examination, it indicates that at least one kidney function of the fetus is normal. If hydronephrosis and ureteral dilatation are seen in B-ultrasound examination during the third trimester of pregnancy, it may be caused by urinary tract obstruction. If the fetal bladder volume is large during B-ultrasound examination, it is considered that it is caused by excessive bladder.

Because it is impossible to determine whether the fetus has abnormal growth and development by simply measuring the bladder size, it is also necessary to make a comprehensive judgment based on kidney color Doppler ultrasound and amniotic fluid volume of pregnant women.