Winter maternity trousers

[sksk]

I'm looking for trousers for work, and, if possible, some trousers for casual use at weekends (though I can get by with jeans at the weekend) but not leggings or skinny jeans and aren't made of just viscose or polyester as I will be expecting in early Spring. I usually feel the cold and often wear thermals when not pregnant. I just can't find anything online and most shops don't stock anything in store. I have bought some 100 denier tights if all else fails and I just have to wear dresses, but, given that I really felt cold this weekend when the temperature dropped to 5 degrees, I don't see how I will cope in the winter! Many thanks.