When I wasn't pregnant I only wore shirts/blouses to work if I either was off to an interview, had meetings or wanted to look smarter.
Thomas Pink/TM Lewin smarter cotton shirts for super smart when I worked in law firms, and variety of Oasis colourful pattern and Warehouse synthetic pastels blouse top for a mix. Also have a lovely smart but sophisticated Karen Millen shirt/blouse - white/ivory. I did buy a couple of cheap H&M patterned blouses/shirts for interviews too - worked very well for interviews at big 4 accountants.
TipseyTorvey - quite a few women do wear suits nowadays - at least in London and certainly in law firms/accountants - I see a few trouser and skirt suit combos on women. Quite a few wear smart dresses but have noticed suits too.
My colleague who's a DD in central government so has to be smart often wears colourful shirts/blouses to meetings with trousers. She gets the smart vibe across but also keeps her personality. she like Cos and other brands.