My new dd (c. a month old) looks like she's getting one - it sticks out quite a lot, and I'm familiar with it because her big sister had one. DD1's went down a lot (was massive to begin with) but she still has a very big 'outie' at 2yrs. Seems a bit weird me having two dds with them, both me and dh have veeeery concave navels. Both were born at 38 weeks by elective cs - does being born a bit early have anything to do with it? Obv. vast majority of 38 weekers don't have them, but I wondered if majority of umbilical hernias were to prem babies?