We definitely would not, regardless of what doctors say. There are so many unpredictable in pregnancy — and so many unpredictable in river rafting. Combining the two just seems reckless, and for no reason, right? It’s not like your last shot at the Olympics or anything! Why take a chance — cheer your friends along while rubbing your belly like a genie lamp (hee hee).
Seriously, enjoy your pregnancy, but I advise not doing something that could have a terrible negative — and unfixable — consequence!