My 5mo dd has a cleft bum - ie where most people have one crease at the top of their bum where it goes to meet their back she has two. The doctor saw this at the 6 week check and said it's nothing to worry about but I keep seeing it and how different it is to other babies and wanted to check and see if anyone else's baby has this. She can't roll yet and isn't keen on putting weight on her legs but seems as physical as other babies in all other respects including using her feet to push against things.