mine got marginally worse - that is, I assume it was pregnancy - I had to get a slightly stronger prescription when I went back for an eye test about 3 months after DD was born. But they didn't get any worse during my second pregnancy so perhaps I shouldn't be so quick to blame it on pregnancy! Maybe they would have been worse regardless. Although the optometrist did agree with my assumption that the change in my eye sight was probably attributable to my pregnancy. Who knows?
Hopefully pregnancywill improve your eyesight - ooh wouldn't that be nice!