If the cat’s an indoor-only cat, where is it going to contract toxoplasmosis? From the dry cat food you feed it? If she (pregnant woman) has an outdoor cat, it’s posible (even probable) that it’s already been infected, and so has she, and so she has antibodies. You can even get tested (and test your cat), and if you have the antibodies, you’re pretty well protected.
I mean, out of however many cat owners who give birth every year, we do not have an epidemic of toxiplasmosis-related problems, I think it’s about 1000 babies in the US a year, and most of those are minor problems. Plus, not all of those will have been due to a cat, as you can get toxiplasmosis from undercooked meat (like where the cat would get it).
Lots of web references, like:
Don’t clean the litterbox if you have an outdoor cat who has not previously been exposed to toxoplasmosis, and if the neighbourhood cats use your garden as a litterbox, maybe get someone else to garden if you haven’t already been exposed. But let’s not go overboard about this.