My DD has one. It sticks out pretty far and is bruised on top b/c of the pressure, but as long as it can be pushed in easily it's fine. Babies don't automatically have an outie due to this, though.
DD has a little one. It seems much smaller already since she was born (she's 4 weeks). Most of the time it looks normal and once in a while I notice it sticking out a bit.
An infant at the daycare I work at has one and it was on the larger side. She's almost 12 months and it had gone down on its own so much, it's barely noticeable!
DS1 had one and it cleared up on its own. K has one too and our pedi expects it to resolve itself. If it doesn't they can do surgery like PP mentioned. Oddly enough, N does not have one, his belly button looks perfect already.
@MrMrsandbaby My personal experience with umbilical hernias is to not worry about them or get them fixed unless they are causing damage to the colon (popping through/getting pinched) I had mine repaired at 17 and have had it "re-repaired" 4 more times since then because it was causing damage.The reason I get re-rupturing mine was because I am a very active person. I feel that if you were to have a child's fixed since they are so active you would have a similar outcome (imagine keeping a 5-year old in bed/relaxed for a true 4-6 week recovery. My 5th repaid required A 4X6 permanent mesh with 28 permanent staples in my abdominal region around my bellybutton. I do not recommend it. it is very painful and not worth it if it isn't necessary.
Re: Umbilical Hernia
to this, though.