Please don't assume that they would get in touch with *you* and just because they don't means they don't want to hear from you! You couldn't be more wrong! I know that I would give ANYTHING to hear from some of the moms' I felt I bonded with when I was caring for their babies, but so far, none of them have come back for reasons I can only begin to guess at.
If you'd really like to try to keep in touch with them, why don't you write them a letter telling them how much they meant to you and offering them a way they can contact you? Of course, it's up to them if they decide to or not, and even if they don't, you shouldn't take it personally. Nurses become attached to the babies and families we deal with, and we grieve for your baby also. Different people deal with grief different ways, and it may be to painful for them to write you back or call you (sometimes, sad as it is, it's "easier" to forget...easier on our hearts sometimes to not deal with the reminder that maybe you couldn't save the baby, or have to face the loss, you know?).
Either way, I'm sure they would be touched by a letter from you telling them how much they impacted your life.
Just remember- we don't forget, just like you don't forget.
I know I fall in love with the babies I take care of like they were my own children. I worry about them after they leave the unit, and I worry about their families when something happens to them. I just don't talk about it out loud very often. We sometimes have to keep a brave face at work, but my husband has seen me cry for these babies and cry for parents just like you, and I know in my heart that those nurses are the same way. Let us know what happens, okay? And good luck in nursing school! Your ability to be compassionate and relate to the other families you'll come into contact with one day will make you a very special nurse.