Women and men should both bear the costs. However, seeing exactly how much a newborn can cut into time a woman would otherwise spend working makes me (against my better judgement) worry about hiring women.

That’s what states are for (caring about the bigger picture in the social contract). In Spain, for example, it doesn’t matter whether you hire males or females, as both will be having 16 weeks of paid leave by next year. If there is no breastfeed, father and mother can basically do the same things (fathers can also take time off for bottle feeding).

You know, some companies and some countries have full paid parental leave for fathers, too. A biopharm I worked for allowed 12 weeks of paid leave to fathers. In some cases you’d be in the same predicament with males. Also, you’re overvaluing productivity.

Oh, I see. Personally I've never lived anywhere that didn't have essentially equal parental benefits for both men and women, so I failed to consider this angle.