My first was born with a full head of hair and the cradle cap made him lose it. It did grow back pretty fast though! My daughter was born 11/6 with a full head of hair but hasn’t had any fall out yet. I am sure it will happen though.
It all of them. 2/4 of mine kept it and I think this guy is going to keep his too.
My first daughter was born with a lot of hair. She didn’t lose any on top but she did on one specific spot on the back of her head where her head would always rest when sleeping