Reddit reviews When Couples Become Parents: The Creation of Gender in the Transition to Parenthood

Pregnancy, breastfeeding and recovery are hardly insignificant. The physical toll is immense, of course, but an increasing number of studies document the ways in which a woman's brain is also permanently altered by these processes.

But putting that aside, I'm afraid it's naive to imagine that liberal egalitarian couples manage to parent equally. You might want to check out the below-linked book, an academic study of heterosexual couples in the first year of parenthood. In fact, the researcher finds, the couples most committed to equal parenting -- and who, before kids, had truly equal partnerships -- have the hardest time with the transition. None are entirely successful in equal parenting -- NOT through any fault of their own, but because our entire culture is geared toward placing the main burden on mothers.

link to book

So yeah. It's almost always an easier job to be the dad, even if a man's intention is to be a totally equal partner. To change this would require us to change the very way we as a society imagine parenthood, to say nothing of the necessary infrastructural changes to do with work, leave, childcare, and so on.