It entirely depends on your boss / line manager, I think (head of dept in traditional structures, or head of research group / subject stream / random silo in other stoopid management structures). Whoever makes decisions about your workload, admin jobs, teaching allocation, etc.
I've previously had a misogynistic sociopath as a HoD who described maternity leave as a baby holiday, wouldn't make any allowances for moving meetings or lectures to family-friendly hours, and openly denigrated anyone who went part-time for childcare reasons. No men took any extra parental leave, or asked to work flexibly, or said openly they had to leave early to pick up the kids, etc. under his long reign of terror. (Several women left due to feeling their careers were being stifled.) There was a general culture that kids were incompatible with a serious research career unless you had a stay-at-home partner - many colleagues (both male and female) with kids did so, to an extent I haven't seen elsewhere.
I've also had a decent human being as a HoD who did her damnedest to make working family-friendly, including encouraging meetings to end before 5pm, working from home during school holidays, etc. Both men and women took the opportunities given, and it was fairly common for fathers to take extra leave when children were born, or stay home to look after a sick child, etc. Everyone was aware some people had kids or other caring responsibilities, and it wasn't seen as a problem. Kids were not seen as a barrier to a research career, and all levels - L, SL, prof - had excellent grants and publications regardless of kids or not. (Btw, this dept did as well in the REF as the previous one with the psycho head). A few colleagues had SAH partners but most didn't, and there were quite a few people whose partners were also academics ore than I've seen elsewhere).
I've also had HoDs somewhere in the middle, who through indifference or ineptitude didn't engage with any family-friendly issues and just let things drift along. The culture then tended to regress towards the mean... as in any accommodations for childcare tended to be taken by women, and only occasionally by men. Colleagues would (for example) move meetings to accommodate someone picking up kids, etc. but would grumble if it happened more than occasionally. There was an overall culture that kids got in the way of the job rather than being a normal part of life.
Depressing when I look back on it, but the good news was how fast the culture could be changed by a new HoD if they were determined to change thugs for the better. Athena Swan helps a lot in that regard for sciences.