the nurse does all the labour bit, then the doc comes in and catches the baby! does this happen with all normal deliveries?
Yes, pretty much. Where I work, the typical patient may see the doctor once (at which time they break their water, usually during morning rounds- hurry up and break all the inductions), typically for 5 minutes tops; then when baby is on the perineum and really to fall out for another 10-15-20 minutes. If the patient misses morning rounds, there's a fairly good chance they won't see them at all until delivery.
What do midwives do in the states, as here in the UK, its our job to manage labour and delivery, unless it goes to forceps/c-section etc.
Certified nurse midwives (CNM's) here manage healthy pregnancies, labor, delivery and postpartum as well as well-woman care (pelvic exams, paps, birth control, menopause tx, etc.). They usually work in hospitals/ are in practices with doctors (though not always), sometimes do freestanding birth center or home births. They tend to stay with women more during labor than doctors. Complications, c-sections, hi-risk are referred to doctor.
Non-nurse midwives (lay midwives, CPM's, direct-entry MW's) rarely to never work in hospitals/doctor practices & usually do home or birth center births.