Off roading?

Erin
Is it safe to go off roading while pregnant? If not, why? Google has all these people saying no and it's risky. But why?? What is the medical reasoning and why is it risky? I've never heard that being slightly jostled around is problematic to the baby. But I could be wrong
Now by off roading I don't mean rough terrain. I mean we go like 12 mph tops, through trails that are mostly puddles and some small "obstacles ". Nothing accident worthy.