It is true. It can be dangerous for a pregnant woman to change the litter box.
The litter box is a container that functions as a toilet for pets, especially cats, when they are indoors. It is risky for pregnant women to change the litter box because toxoplasmosis, which is an infection caused by a parasite, can be passed to her if she has contact with cat feces. Furthermore, her child might also become infected, which might bring about birth defects and even brain damage.