dilated kidney

Alexis
We just went two days ago for our anatomy scan and the tech said everything had looked good. We found out we are having a baby girl and she was very active the entire time. I just got a call from my doctor and she said they want me to go back in on October 14 for another ultrasound because baby has a dilated left kidney. Has this ever happened to you? What does this mean? I'm very worried now!