Anecdotally, back in college most of the few women in my course got their grades using their breasts. ~~Fact.~~

The few women i've worked with professionally have been good professionals, some of the best even.

Studies say™ is pretty damn irrelevant these days. If that inequality is true, governments should act. Most have legislation against this kind of legislation, but that's it, paper. There are very few government officials actually controlling these issues proactively, if any at all. Plus few companies make salaries public and it's not common to discuss paycheck.

Ensuring neither the company nor the worker gets penalized for pregnancy/newborn care would probably help a lot.

No, i'm not denying there's a bias, there most likely is, especially in IT. But in paychecks, for that reason alone, not so much... for sure there are lots of people in the same company in the same role with the same skillset and generally about equal in all the job requirements who do have differences in their salaries, but i'd wager that's more related to how well they negotiated during the hiring process.

Edited to add "Anecdotally, ".