The problem with children is that they need care. First, you have to take time off to actually birth and bond with them, and then, even when you’ve secured daycare or the kids are in school, things happen and you have to scramble. (A “snow day” for schools won’t necessarily result in your job being closed, but there goes your childcare.) And if you’re in the “sandwich generation” you’re taking care of children at the same time you’re taking care of elderly parents, having reliable care can be even more difficult.