My son was a 36 weeker, and while he had no breathing difficulties or anything, he was really small, even compared to some other 36 weekers in there. He weighed 3 pounds 5 ounces, had to stay for 4 weeks to put on weight and since then has had developmental delays in pretty much all areas.
He was also classified as being a preemie and was followed as such, with a corrected age and everything.