Hard to say. However if we are not close to 50/50 we should ask questions. Any imbalance could be a sign of something deeper being wrong - perhaps there is some discrimination of some sort? If the answer finds a genetic reason that males prefer engineering, then that is okay, so long as the genetic influence's affect are equal to the affect on society.

Right now I have no idea. I don't think there is a genetic reason for females to not become engineers, but I haven't studied it so I have to remain neutral on the question.