As someone who is on week 17 of bedrest with my second pregnancy, I beg to differ that bedrest does not have an impact. I was on bedrest for 12 weeks with my first as well and delivered her at 39 weeks. I will be 36 weeks tomorrow and believe that without this intervention I would have lost my baby (even after having a rescue cerclage placed).
Now, every situation is different....each & every one. But, not all medical intervention is bad. Not all women are attention seeking in this realm (your sister might be, I don't know her). If you're faced with potentially losing your baby, you'll think LONG & HARD about your options and would do most anything to ensure their safe arrival. Does that mean you go into the process ignorant and not try to educate yourself - heck no. But if a woman trusts her doctor (which she should!) then that's what matters.