You can make implicit inferences... e.g. younger people (below 25) are less likely to be parents anytime soon.
Also, there could be post-hiring pressures, motivating employees to not have kids in order to continue their stellar career trajectory (this probably already happens, and I think it's something that should be addressed by some kind of government-provided incentives... I was thinking something like tax-breaks or even tax-rewards for parents, or possibly public housing).