I'm not sure why this has to be so complicated. Company - what is the male/female ratio in the pool from which you pull your talent (e.g. A and B students graduating in North America with an IT related degree)? What ratio did you actually hire? Did those two ratios vary significantly? If so, why? 
IF women are genetically predisposed to not like IT, then this will be reflected in the pool from which you pull your talent - not your problem.