Carrie Underwood thinks her ''bum's a little nicer than it used to be''.

The 'Blown Away' hitmaker, who has seven-month-old son Isaiah with husband Mike Fisher, says her post-baby body is different, but she's embracing the changes.

The 32-year-old singer, who follows a vegan diet, said: ''I weigh more than I did when I was at my smallest, but I have a lot more muscle tone. I feel like my bum's a little nice than it used to be.''

The blonde beauty's relationship with professional ice hockey player Mike, 35, has also changed since they welcomed Isaiah into the world, but they are keen to have more children.

She told PEOPLE magazine: ''Your marriage does change a lot when you have a baby. It's a whole new dynamic.

''If we could keep having babies like Isaiah, we'd probably have quite a few.

''I would love to have a girl.''

But Carrie claims becoming a parent hasn't really altered the style of music on her new album, 'Storyteller.'

She said: ''I feel like everybody expected me to have an album full of 13 mommy-and-me tracks. Like, everything would be sentimental and mushy. I'm still me, and this is just another layer.

''I don't want to lose myself in being a mom.''