At my appointment the other day my OB told me I will be going on bed rest at 20 weeks. At the time I didn't think much of it and forgot to ask why, then thought...wait a minute I have seen lots of posts saying I ran with twins up until such and such a date. This really got me thinking. Before I was pregnant I weighed 120 and am 5'5" ...so it's not like I am obese and they need to take extra measures. To add, I am also very physically fit and my tests have also shown that I am healthy.
I called the office to ask why and they said it is usually just his policy...I will ask him directly at my next appointment, but
any thoughts? 
Re: Bed Rest at 20 weeks?
Seems odd to have a blanket policy that every goes on bedrest at 20 weeks. Are you seeing a perinatologist too?
I made it to 30 weeks. At 28 weeks my fFN test was positive, so they were a bit concerned. A few days ago OB decided it looks like my cervix has shortened, so I'm on bedrest for at least 2 weeks.
I was walking 2 miles every-other-day until the fFN test (but perhaps the two are linked...)
Unless you have some special condition, I cannot imagine why you'd need to go on bedrest at 20 weeks. I know some OBs recommend quit working at various times (usually around 28w and later). But flat out bedrest just seems a little much - particularly that early in pregnancy.
My peri (whom I saw exclusively) had no hard and fast rules for quitting work and bedrest. I know at 20 weeks I felt great. And in fact, my peri had no problem with me traveling to the UK at that point.
I would question your OB and without a good reason for bedrest at 20 weeks, I'd probably look for a new OB with experience with multiples or at least insist that the OB consult with a peri.
I was on BR much earlier, but for a reason. If I hadn't been on bedrest already my OB typically took twin moms out of work by 29wks... though she would be open to letting someone go later depending on the circumstances.
Bedrest can mean different things. I doubt your OB would have you confined to bed, but rather at home just taking it easy... at least I would hope so. Strict bedrest for an extended time takes a heavy toll on your body. I was like a straw man with no stuffing after my c/s. It was a difficult recovery that lasted many months even though I had some physical therapy.
I actually WAS put on bedrest at 20 weeks, but I had no cervix and had bled for two months already.
Before that, my peri told me that she doesn't recommend bedrest for any multiple pregnancy unless there is a medical reason to do so. Many women can go very far, provided they rest and take care of themselves.
I was just unlucky.
Lost Lilah (Audra's twin) at 26 weeks. Cause unknown. Forever in our hearts