The hospital I work for has a combined labor, delivery, postpartum set up. I got in by working in postpartum first, otherwise I would've been in your same boat. I would also get whatever certifications your facility requires of a labor nurse, if you can. Take fetal monitoring, NRP, STABLE, get your ACLS... These certs may come out of pocket, but then you'll be prepared and you'll have a leg up on other applicants. Take CEs with a maternal child focus. Load your resume with content that screams "I want labor!!!" And NETWORK!! Just like the others said... Make friends, get it know the boss... Keep trying!! You'll get there!! :)