I thought it takes a man and a woman to make a child. In addition, in many countries, both the man and woman can take leave when they have a child.
These sorta points greatly weaken your argument. You using child care as an alternative explanation towards why woman may make less is likely a symptom of the bias women face in the job market.
It feels a but ridiculous that you are using “less work hours due to pregnancy and childcare” as your primary explanation for why women make less over multi-decades long career.
Women go on pregnancy leave for months. How can this explain less pay for years of working?