I would suggest that you call the nurse manager of L&D and/or mother-baby and request an informational interview. This is an opportunity to speak to the manager strictly on an informational basis, not as part of a job interview
. Express your interest in L&D and inquire as to what education would best qualify you for a position there. I have not worked in any hospitals that employed LPNs in L&D, but know of many that utilize LPNs on mother-baby, which would be excellent experience for a future L&D RN. Also ask about elective courses in nursing school
that would best prepare you for a role on L&D, volunteer opportunities, etc.
This is a good way to make yourself "known" to a potential future employer, especially if you present yourself in a very professional manner (well-dressed, questions prepared in advance).