Studies have been done; I'll have to look through our files. None, though, were done prior to the widespread use of cytotec, which is really shameful. However, studies are showing that it is safe *with judicious use, within certain parameters* well, at least as safe as pitocin.
Of course, if the standard of care weren't that women shouldn't go overdue, this debate would likely be fairly moot.
Somewhat off topic (my apologies to the OP!):
We have used cytotec with about 50 women over the last 3-4 years. Some were to induce labor when the baby had died in utero, and the mom did not go into labor within a couple of days. Mostly for moms approaching 42 weeks. We don't set these parameters; ACOG and NACC do. If we "let" someone go overdue without attempting to get labor going (and they don't accept accupuncture, accupressure, chiropractic work, sex, or castor oil as attempts) and a baby died, the state could sue us, even if the parents didn't want to, for practicing outside of the standards of care. If this weren't the way our system is, I doubt very much we would have any issue with most moms going 42+ weeks. It really stinks.
We have never had a rupture or hypertonicity (we do have Brethine at the bedside in that event). Moms with a recent history of asthma and moms with previous uterine surgery can't be given cytotec; it is too risky. Labors DO seem to go alot faster, and I think they are much more intense, by the mom's response. It is harder for them to deal with the contractions, since it is artificial. We have never had to transport because of fetal distress, but that could also be because we don't break the bag of waters, like most practitioners do when inducing.
We have also not noticed a drop in fertility in women after the use of cytotec, to reassure you. I would also add that we have a one page consent that women must sign before we begin the cytotec, outlining our dosage and protocols, and the potential side effects of cytotec, including rupture, hypertonicity, fetal death, hemorrhage, hysterectomy, etc. We hold no punches. We tell women to look on-line, and we have the mothering magazine article available for them. We also have the medical articles discussing cytotec available for them. Some women refuse the cytotec, and that is totally okay. But if they go over 42 weeks, they can't have their baby at our facility (state and NACC rules, not ours); most choose the cytotec over a hospital birth. They are between a rock and a hard place, no doubt about it. And it is completely unfair.
Instead of crying out against cytotec, I wish that those who vehemently vilify its usage would instead turn their passion and energy to changing our medical and legal system. So what if cytotec is banned for use as a cervical ripening agent? Something else will be found and used in its place. Instead, change the rules we have to operate within. Why should women be forced to have their baby by 40 weeks? Why must labors procede within a certain time frame? Why must women be monitored so closely during labor that they are constrained in their movement? Why are epidurals pushed? Why can't doctors spend more than 5 minutes per prenatal with their patients? Why aren't midwives more accepted, especially when they don't act like little OBs?
Our medical and legal systems are sick, and they are dictating how women are being treated, or not treated. If these things would change, the entire issue of cytotec, pitocin, even c-sections would be moot, as they wouldn't even be issues. Pipe dreams, probably. But boy, wouldn't that be the day, when women were treated with respect and dignity? When they could be partners in their care, and all their wishes could be honored, without the fear of state-sponsored litigation and possible jail time? I hope that this exists for my daughters.