If you are premature there still is no LET or ALLOWED as far as Homebirth is concerned... it will be recommended, and it is your choice to go in or not. You will know at the time how you feel about this, and it shouldn't stop you from planning a homebirth... and as MM has said it is easy to plan for a HB and then have to transfer if you feel you need to, rather than wantting to be at home if you are in hospital.
Risk of uterine rupture is 1 in 500 that is in fact 0.02% and if it does happen it happen very slowly, so there would be plenty of time to get in. Plus your care at home will be 1 on 1, not something that your likey to get in the hospital or birthing centre. At home your MW will NOT leave you to go and attend to another lady.
Also at home you will be monitored, but you won't be constantly monitored, as I'm sure you were with your first. There are many variences with babies HR during birth that isn't fully understood and some of it occurs naturally. You also won't become distressed yourself.. having to listen to every beat of your babies heart.. and wondering why it varies so much - as there is a significant link between mother's stress and the babies distress. It is a factor of the slipery path on intervention that leads to so many of today's strange stats on numbers of c-sections in the "modern" world.
Ultimately it is about your choice, based on evidence and information - so you can make an informed decision; and where YOU will feel most secure and comfortable.
XxX
P.S I have jsut been talking to a friend of mine who is just 3 weeks ahead of me in her gestation, and she is trying to wiegh up the benifits of a vbac v elective. I couldn't empathise how important it is to her to be fully informed of the stats, research and information that is availible on VBAC. She is 20weeks, and although she has already had several meetings with her consultant.. the risks of VBAC have been explained to her, but HAVE NOT been put into context (she hasn't recieved any information on the data). How is she meant to make an informed decision on her body or baby, without this?? It boggles the mind!
Her first birth baby was back to back, and she was labouring slowly (as women ofen do with baby in this position) so she was on the clock, offered to rupture her membranes, then she didn't progress enough, so she was offered IV induction drip, got to 7cm, she was in alot of pain and very tired, offered and epidural, still failure ot progress, she and baby bacame so distressed after an ordeal of 17hours in the hospital, she was offered the emergency c-section after 24 hours. I hope she wouldn't mind me telling you, that this is a classic slope of interventions.
You offer yourself a better chance of a normal delivery and a lower risk birth by planning a homebirth - which a statistical fact.