I'm not an expert by any means, but I use this one and really like it:http://www.amazon.com/Omron-HEM-711-DLX ... B000O5D4TA
The cuff adjusts to your arm size and senses when to stop squeezing, which is really nice. (A lot of them end up hurting me, even when I use the appropriate cuff size.) I have checked the reading I've gotten from my machine vs. my OB's office and vs. my MFM's office and it has come up really accurate.
I think most should be fine, but bring in to your doctor's office to see how they compare. And avoid the wrist ones, I have heard they aren't nearly as accurate.
Me (29) DH (30)
#1-Olivia Caetlyn-9-28-09-9-28-09, 23+2 wks, emergency classic c-section, class I HELLP, IUGR
#2- Lucas Oliver (rainbow baby)- April 2011, 36+2 wks, HELLP and pre-e free! (lovenox and LDA pregnancy)
#3-Matthew, late October 2012...mostly normal, 37 wks, (lovenox and LDA again)
My blog: http://www.butterflies-and-rainbows.blogspot.com/