I had the chance recently to attend a birth where the family's first language was Spanish, and realized how rusty my Spanish has become. So, here, a list of words I learned/remembered that might be useful at a birth.
lo siento-I'm sorry
espira-breathe out (blow)
al baño-to the bathroom
empuje-push! This also means "shove" so is only for use if you really, really want a strong push.
el bebé que viene-the baby's coming!