Hehehehe, I saw what you did there.Here would be my question...
This article stated that UPS made accomodations for people that are injured on the job and who have disabilities.
If you're injured off of the job, then does UPS accomodate it? For example, if a person was to throw their back out playing football, or break their arm playing basketball, does UPS have a policy to accomodate those individuals with "light duty"?
If they do then I'd absolutely say that a similar policy should be in place with regards to pregnancy.
However, if they do not, then I don't see any difference here. Pregnancy is not a federally protected or medically designated "disability". It's not a handicap. So the closest it could be compared to is an injury. A woman is not going to be getting pregnant as part of her duties on the job, and as such this is an off the job impedement to her work. Just like UPS shouldn't have to bare the brunt of you injuring yourself while playing basketball, they shouldn't have to bare the brunt of you getting pregnant as well, if either hurts their business.
Now, personally I think they should accomodate her if at all feasible to do so and still get the necessary productivity from the shop as a whole...but I don't necessarily think they should HAVE to accomodate her if they don't for other instances of peoples actions outside of work causing them to be limited in their ability to do the job.