I've never heard of that one before.
I've lifted plenty of heavy things in my time and haven't have any problems with pregnancy.
I have been in hospitality for 16 years and have many female friends in the industry. This is a bunk story. Because we lift from a standing position there is little mid or lower back stress. The weight is taken on the hands & arms.
Its only kinky the first time.
As Far as I know she could only harm herself if she was pregnant. if she was pregnant she could detach the baby by lifting heavy things or stretching to high above her head and cause herself to abort.

Behind every strong soldier there is even a stronger woman who raised him " Proud Army Mom" Geez I wish somebody would have told me that when I used to work at a plant nursery hauling 50 lb+ balled and burlapped trees up a hill to stuff it in some dumb asses hatch back! Yep DamonX once again hit the nail on the head! LOL
Bunny12

Bunny Rabbits cute and fuzzy they want to love you but they have razor sharp teeth - don't piss them off!