Well, you can shoot me as I’m not really an expert and I’m male (as
in "not ever gonna be pregnant so whatta you know?). CLB’s paper
above is indeed a good read, what I read of it.
In a generic sense, though, I could offer some thoughts on this.
There are things that aren’t really SO bad for anybody, like
nuisance dust. There are things that aren’t so GOOD for anybody, and
require greater care - acids, for instance. Those things aren’t
especially bad for pregnant women - that is, no worse than for
non-pregnant women. What you’d need to pay more attention to is
teratogens and carcinogens, real or imagined. Those are things like
plastic resins, aromatic hydrocarbons like MEK. Methanol maybe.
Those are the things that cross the line and are pointedly bad for
the fetus itself. Dichloromethane (Attack) is both of those - I’d
say a pregnant woman shouldn’t be in the same room with it.
Of course, it depends on your own comfort level. I’d have no problem
with a pregnant woman polishing, for instance. Cyanide plating, no.