No clearly, if someone is choosing ARM rather than prostin because they would prefer to do it a more "natural" (i.e. drug free) method of induction then they need to understand that a) there is nothing natural about ARM and b) drugs may be required further down the line, though you hope not. And no, using the line that ARM is a more natural method is not a good way to persuade who doesn't really want induction to have one, but people do resort to funny tactics when they are convinced in their own minds that induction is the best course of action, regardless of how induction is achieved.

I don't think very many units would want to ARM, and then just leave be beyond four hours. Lots of units reassess after 2 hours and synto put up at that point. If you are having lots of successful ARM-only inductions without synto in multips, then I suspect it is because you have a pretty selective policy when it comes to ARM, and that prostin is widely used in women with a favourable cervix. (i.e. your local practice regards being "ARMable" as a necessary but not sufficient reason to ARM, whereas many - perhaps most - other units approach this differently, as described in the opening post - If you physically CAN perform amniotomy on a woman booked for induction, then you should.)