Donald Trump said they were "inconvenient". Honestly, there is an element of truth to this. I operate a small pop stand. The size of my crew is less than 10 employees. In 35 years, I've had one full-time and one part time male employee. The rest have all been females the majority of reproductive age. I've been through the maternity cycle numerous time. The truth is, that for a business of my size, it is inconvenient. I've never discriminated against pregnant women or violated any applicable laws. However it is a pain in the neck. There's the lost productivity. Covering for the employee when she's out on leave. They will sometimes promise to come back to their job after maternity leave, and then either tell you they're not going to come back at all, or that they want to work only part time. Then, when the kids are sick, its the mom and not the dad that has to take care of it.