Have found an underwired maternity bra that goes up to a H cup! It's by Anita Maternity and (apparently) the wires are softer than normal, and the bra is cut slightly differently to normal making it safe to wear during preganancy. Have just received mine from look at this pageand it is very supportive even for big boobies. Its not a cheap bra, but there is free postage. There's also a nursing version, again up to a H.