Hi Lemele,
I had an appointment with what is called a PBAC clinic (positive birth after caesarian - bleugh) yesterday and discussed this with the registrar there. My situation is somewhat different, having a singleton pregnancy, but because I have developed gestational diabetes and my previous baby was on the big side (although not through g.d.), there is quite a likely scenario that the OB will start recommending induction for me at around 37-39 weeks if no spontaneous onset of labour.
For you, I'd be quite surprised if spontaneous labour didn't begin sometime around 37 weeks anyway - that's the average gestation for twins isn't it? Although I guess with averages, there are always the ones outlying on either side.
At my hospital, the method of induction for a VBAC would be to use a Foley catheter to ripen and encourage dilation of the cervix to 2-3 cms. This is a catheter with a balloon attached that is inserted into the cervix and then the balloon is inflated, which slowly causes the cervix to dilate. It takes a while but is considered to be safer and just as effective as hormonal gel. here's a link
The next stage if labour hasn't started at this point, would be artificial rupture of membranes - i.e. they'd break my waters. I guess they could also do a vigorous 'sweep' to strip membranes before actually breaking them.
I think ARM can be enough to start labour, certainly a big % of women whose waters go spontaneously are in labour with 24 hours (those that don't are generally asked to go in for induction!) but once it's done the clock does seem to start ticking.
The registrar did say that if labour didn't start after ARM, then there is the possibility of using syntocin to start contractions, it would require continuous fetal monitoring and the amount would need to be carefully controlled as this is something that can increase the likelihood of uterine rupture.
Perhaps you could go back to your next appointment and ask whether these methods of induction could be used first. If they're not familiar with them there may be resistance but equally they could be interested in trying it out.
My feeling was that if I didn't go into labour spontaneously after the first two processes, I'm not sure I'd want to go down the syntocin route as it was most likely to mean my body simply wasn't ready and I'd be in for a long haul, less mobile (because of monitoring and probably epidural) and increased likelihood of distress/failure to progress leading to another emergency c-section. So I think I'd probably elect at that stage for a c-section over introduction of syntocin.
Having said all that (and I apologise for the essay-length post), I'm going to be very much wait-and-see regarding induction anyway, my control of my blood sugars has been good and I think that should reduce the pressure to induce early as a standard protocol for me. I may well insist on an exam to check my body's 'readiness' (Bishops score?) before agreeing and also ask for several sweeps before anything else. I can't really see the point in even getting started on induction if there's no indication in my body that things are gearing up for it even slightly.
Good luck with your decisions - and with the twins when they arrive however that is. I can not even imagine what it feels like to have all those limbs inside