No idea, I’m not as read up on that. It would shock me if it was significantly different just because risk of death from complications is a hard biological line the younger you get, pre-modern medicine.
There are definitely cultures who have practiced polygyny to get around this issue. Some still do today, for example in many different countries in Africa where people still practice a pastoral life.
I don’t see how polygyny gets around the issue of risk of death from pregnancy.
Polygyny would get around the issue of men getting killed.