Maternity clothes / where to buy

My better half is pregnant and I'd like to buy her some maternity clothing (if she buys it, it'll be the cheapest stuff she can find and then she'll walk around for the next new months looking like grandmother...). 

I currently reside in Bangkok so shops and addresses in the big smog would be much appreciated. 

@ moderators: if this is in the wrong forum, feel free to move it. Thanks!