All the employer has to deal with is not to see the employee for a few months, but good management should have plans for that case anyway (e.g. dealing with sickess/accidents).
I worked closely with a German boss for a few years, and the difference is ultra palpable. The entire way of working plans for sane hours (even when this is a struggle to make work), ample time to eat/rest while at work, plenty of vacation time (and no emails or bothering during that time or any time other than standard work hours where the employee is physically present at work), sick time, and time to get organized for projects. Meetings are viewed as last resorts because they're time/energy costly and typically low-productivity. Projects that don't fit that mold are put on hold until there's time for them.
The American style is closer to "fuck you for thinking about slacking".
It is absolutely going to be a huge issue with the company if it is the programmer who built system X and she is going to leave for a year.
And that doesn't even touch the discrimination against those who don't want children in the first place.