Why is it impossible? Nothing about women oppressing men, doesn't sound as ludicrous than vice-versa? Human capacity for evil is evenly distributed between genders.
Don't forget that there was a thing like matriarchy. I'm pretty sure that oppression on some level occurred even then, but since there was little written evidence, its just hard to prove.
As for hiring someone that might have children, and need to take time off, that part should be handled by the state. If someone leaves, the state pays employer and/or women caring for her 1year child. You are effectively down a one person but they are not to blame for things running their course.
That thing shouldn't come into equation at any point.
