Well, maybe not officially, but I have been told that most residency programs will add diversity if possible. For example, in rads, GI, and urology, to name but three fields, women are terribly underrepresented, so these programs are more amenable to women candidates than your standard IM programs.
This is according to the dean of students at my med school.
So, ladies, have no fear: apply for rads even if you think your application is not competitive.