I had 5 babies in the US, last one in 2001 under the care of a midwife, in a hospital, and the first four under the care of a doctors' practice, again in a hospital.
From Wikipedia -- 'In 27 states it is legal to hire a direct-entry midwife, or certified professional midwife (CPM) {for a home birth} It is legal in all 50 states to hire a certified nurse midwife, or CNM, who are trained nurses {for a home birth} though this practice is rare as most CNMs work in hospitals. Some CPMs continue to attend mothers in the 23 states where it is illegal, and can be arrested and prosecuted, while efforts are underway to change the law.
Practicing as a direct-entry midwife is still (as of May 2006) illegal under certain circumstances in Washington, D.C. and the following states: Alabama, Georgia, Hawaii, Illinois, Indiana, Iowa, Kentucky, Maryland, North Carolina, South Dakota and Wyoming. However, Certified Nurse Midwives can legally practice in these areas.
No state prosecutes mothers for giving birth outside of a hospital.'
Since I don't have experience of delivering in the UK I don't know if what I have to say will be useful, but as in the UK you can have positive and negative experiences. From my own observation, what makes or breaks the birth experience is the professionalism of the nurses, their attitude towards breastfeeding and the physical challenges you face in the immediate post natal period. Some of them are bitches with a real hatred of women and a profound disrespect for the 'spiritual' aspect of what they deal with, for want of a better word. And some are utterly lovely. But dealing with one of the former can leave you shaken.
As with Ireland (where I have a sister, and we compare notes) I would advise you to aim for a baby to be born outside of the peak spring and summer months. Nurses tend to have far less to do when the post-natal beds are not full. C-section pain relief tends to be administered on a more compassionate basis than I think they do it in Ireland. Breastfeeding help is spotty at best -- again, you're better off if the maternity wing isn't chock a block.
Hospitals make a great show of having 'natural birth suites' or 'birthing centers' and will tell you if you go on a tour beforehand about all the bells and whistles they have to accommodate whatever your heart desires in the way of a natural delivery in comfy circumstances; birthing balls, tubs, relaxing showers, family rooms -- they are all angling for your business though and that bears remembering far more in the US than in the UK. The reality is that in a maternity unit that delivers 40 babies a day at a peak period (May perhaps) there will only be one mother at a time in the birthing suite with the lovely birthing ball and the tub, etc. If you arrive in labour and the suites are full you go into a room and lie on a bed, usually with fetal monitors strapped around you, and machines blipping and flashing.
You can choose whether to have an epidural or not. I had one for DD1, then didn't get one for DS as the anesthesiologist was the only one on duty -- horrible case of overbooking C-sections plus an unusual number of walk-ins during the month of May and he simply didn't make it to me in time. I didn't bother with the next three after that. Gas and air are unknown and unused.
They will set you up for an IV (I recommend arm or wrist instead of back of hand) when you are admitted, whether they actually start you up on a saline drip immediately or not; a saline drip is standard in the hospital where I had the first four. They then use the already inserted needle for pitocin, anti-nausea medication, or a blood transfusion if necessary at any point (rare). Delivery is nearly always on your back, or half-sitting, or lying on your side (midwives are usually much more likely to suggest different positions ime)
One thing that differs widely from doctor to doctor is the amount of time you will be 'allowed' to go overdue; mine was a strict 'one week and you're finished' man; there are lots of inductions as far as I can gather anecdotally, and these tend to result in c-sections for failure to progress. I managed to make them stop pressuring me to consent to induction after going along with it for DS. Although birth is more medically managed, doctors can't abduct you and force you into the hospital; after you get to the hospital however, read the waivers you will be asked to sign in the reception area very carefully, or get a copy of what to expect on the net. It's not a great time to try reading and making sense of legal mumbo jumbo but you may be signing away quite a lot.
My last birth was after a pregnancy during which I had GD and anemia; induction right on the dot of 40 weeks was the protocol she followed, so medically speaking not at all different from what a doctor might have done. She tried a cervix softening gel first, as had happened with DC4 under the care of the doctor (it worked that time with no need for the pitocin), and when that had no effect, she had to do the pitocin within a certain period of time, and things progressed from there.
Some hospitals insist on taking the newborn away to the neonatal nursery for a few hours 'observation' after mother and baby have recovered in the post natal recovery area, and they do this no matter how distressed you may be or how unnecessary it is from a medical pov. There is a charge for the baby's time in the newborn nursery, and my suspicion is that it can only be justified by reference to the hospital's bottom line. Usually, if you are lucky enough to give birth in a free standing birthing center or in the birthing suite of a hospital, they leave the baby with you and there is no 'observation' necessary. Circumcision in my experience with DS is done only with express permission and the signing of a consent form, but there have been horror stories as noted. It's still a popular procedure in the US. Eyedrops and a battery of newborn blood tests are required by law in a number of states.
You will have to start by finding out what hospitals and doctors are in your insurance plan, and then ask and ask and ask to sort out what hospital or center you think suits your needs. Insurance generally does not cover the cost of assisted home birth afaik.