To design? Are you a creationist?
Assuming you're just confused, evolution doesn't "design" life. It's just a "whatever works" process.
For example, angler fish have a lure that resembles prey for their prey. This has been selected by the eyes of their prey. It's not that the prey wanted their predator to fool them, it's just that angler fish with bad lures starved and died off.
In the case of humans, if what your parent comment suggests is true, then it would just be that some women had some sort of defect where they couldn't give birth after some point and that turned out to give their grandchildren an advantage over the grandchildren of women without the defect. Over a long period of time, more and more descendants with defective reproduction genetics would survive compared to those without and so it becomes prevalent.
That's how evolution works.