Distended bladder in baby?

Brittaney • I have an amazing 6 year old who is my world. And an amazing husband who i thought id never find after my first who treated me like crap for 12 years!
Has anyone else had this come up in an ultrasound? My sister had an ultrasound done today at a 4d place,they called her on  call dr at her regular obgyn bc they think they saw what was a distended bladder on the baby. Anyone ever have this or know anything about it?