A friend of mine is pregnant and we use elevators a billion times a day traveling from floor to floor (our work/academy is split of 2 floors). The elevators are pretty strong when you reach a level and the jolt is like a freekin seismic toss. Is it okay for baby? She is 10 weeks.
The Labor & Delivery in hospitals is reached by elevators :P do you really think they are going to let someone pregnant climb a trillion stairs? The baby is fine, as long as she doesnt fall & hurt herself.
I can't see how unless you're drinking alcohol in the elevator while toxic gases are being pumped into it.