Enlarged fetal kidney in second trimester ultrasound

Patient: I am a pregnant women in 16 week and the embryo kidney is shown in echo that is 3 times larger .is it normal?

Doctor: Fetal kidneys are first visualised on ultrasound at about 9 weeks of pregnancy. While it could be normal this will need to be followed up in subsequent ultrasoungs. However an ultrasound showing an enlarged kidney could indicate a  polycystic kidney  which is multiple cysts present in the kidney thus leading to enlargement. If both kidneys are involved then it is called Infantile polycystic kidney disease which is extremely rare about 1 in 50,000. If only one kidney is involved it can be just benign polycystic kidney.This could also lead to decreased amniotic fluid in the uterus. You will need a repeat ultrasound to see the progression or regression of the same.