There are a lot of workplaces that will simply not allow someone to take months of unpaid time off work. A woman will be eligible for some medical time off (generally unpaid) - but the father (or non-birthing parent) generally cannot take time. The main exception I see to this in most employee handbooks is time off for adoption.

Now, this is talking in general and not about tech per se, so if someone is really lucky they work at somewhere that doesn't expect them to do work every week to keep their job.