There could also be other things too that Im not aware of!
Can you give more info?? Like what is the context of post?? I know there is a leap procedure done on a womans cervix that can affect the length of it and possibly affect the pregnancy ( i had it done due to having cervical cancer cells). But Ive also seen a few posts on her about babies due on february 29th which would make them leap year babies. Like I said can you give us the context of the post?