My new one was premature. I didn't know about it until they started. I don't really think the parents realize he is delayed. He has no medical issues other than he is at about a 10 month level as opposed to 12 months. My other infant is 1 month older and there is a very large gap! It is a lot of extra work! I usually look for kids over 18 months but had to take 2 at 12 months to fill spaces. It's exhausting lol