I think as a general rule, if you're thinking of doing something like this, do it after your first trimester has ended. I had DH spray the house and do a spider bomb out in the shed, but made sure I was out for the day and didn't come home until the house had been aired out for several hours afterwards.

I agree, though, there are some good spray on flea products in non-aerosol formulations, perhaps you might find those useful as an interim measure?