"By eight months, the foetus spends an estimated 25 per cent of its daily protein intake on manufacturing these hormonal messages to its mother" That's a lot of energy. Further, human mothers have a high chance of death from natural childbirth compared to most mammals.
Further the energy costs, pain, and suffering from monthy periods has a lot to do with the conflict, wolves for example don't suffer nearly as much.
Realistically it's at best a local optima, but robustness and adaptability are hindered but such inefficiency.
Inefficient on an individual level, but the adaptability and robustness is more on a species level. It's probably pretty efficient in that regard.
A high risk, high reward strategy that works out well for humans that survive and end up with large brains, but terrible for certain individuals for the reasons previously outlined.
Further the energy costs, pain, and suffering from monthy periods has a lot to do with the conflict, wolves for example don't suffer nearly as much.
Realistically it's at best a local optima, but robustness and adaptability are hindered but such inefficiency.