My son is 1 1/2 months old. During pregnancy, my ultrasounds had shown dilation of kidneys of fetus. The ultrasound at birth of my baby showed normal kidneys but mildly prominent extrarenal pelvis. However, at the end the scan conclusion was ‘normal’. At 6 weeks, another ultrasound was done. Again, the kidneys were seen to be normal but pelvis was dilated. The doctors are talking about some measurement (1.2 cms) which is significant and advising prophylactic treatment. What does this mean? Is this a major problem?