Dilated kidney at 20 weeks.

I went for my anatomy/gender scan today. The doctor said everything looked normal and she is growing like she should. But she did say her right kidney was dilated /swollen a bit. I know the Dr said this is very common and often goes away on its own but I just can't help but worry about my sweet little baby. Has anyone else had this occur during pregnany? Just curious. I have faith that my sweet girl will be fine..just a worried first time mommy here.