Our fitness director and spinning instructor taught class up to a couple of weeks before her daughter was born, and now she's doing it again with her current pregnancy. She said she really has to watch her HR although I don't remember what the max was she could go to. I'm sure it may be different for you anyway.<br><br>
Regarding the monitor, Polar makes good ones but they can get pricey quick depending on features. I bought a Sigma Sports PC-9 and have never had any trouble with it. I think it was about $45-$50. It might depend on if you'll use it after the pregnancy as far as the features you look for--could you talk Nate into a Garmin 305 and use the HRM features off of it? Anyway, the Sigma came with a little bike mount so you don't have to wear the watch while you're cycling if you don't want to--I have weird circulation and sometimes my wrist will hurt from wearing a watch. It also has an alarm when you go from one heart rate zone to the next (you enter your age, gender, and you can personalize your HR zones), which might be handy if you're trying to keep your HR below a certain level and don't want to be looking at the watch all the time.<br><br>
Lisa