Does preemies also follow the leaps?

Yes, they do. You can use the EDD to gauge. Because the timing of the mental development of a baby is related to the age since conception and not to the age since birth. That being said, I have a friend whose baby was born 4 weeks earlier and her baby appears to go through the leaps slightly earlier than predicted (when based on EDD). So It appeared that her girl will go through a leap between the actual birthdate and EDD.