I had one at my very first "er...I'm pregnant" appointment with my GP when I was pregnant with ds1. She looked at my notes, saw I was due one, and said "well...while you're here." I knew nothing then (I was about 6 weeks pregnant) so went along with it. If I was in the same situation now I wouldn't let one be done. When I was pregnant with ds2 I was also due a smear and I asked my (new) GP out of interest. She said 'technically' there's no risk - but she wouldn't do one (partly because if the woman did subsequently miscarry she might feel it was her fault for having agreed to a smear). Also (I know this from my dodgy smears in the past) giraffeski's right: pregnancy can cause changes in the cells so a smear can't even be relied on in pregnancy.