WaPost published After a Baby, Full Time or Part? It is subtitled, When Family and Career Collide, Working Mothers Struggle With Their Answers. Fathers, presumably, experience no such conflict.
I say, beware of the off-ramp. How do you know you will find an on-ramp when you are ready? In science, there is no on-ramp. Well, NSF (National Science Foundation) ran a one-time call for proposals for women who experienced career hardship due to family obligations. 7 years ago. I haven't seen anything else since. Until I see on-going programs with all the science funding agencies, until I see national labs allowing part-timers to act as P-Is (principal investigators) of projects, I would warn women to steer clear of the off-ramps. Don't even mention conflicted feelings about leaving your child.