It's not unheard of to die of cancer or heart disease before having children, but it's uncommon enough (even compared to accidents and suicide) that I wouldn't

It's not unheard of to die of cancer or heart disease before having children, but it's uncommon enough (even compared to accidents and suicide) that I wouldn't expect them to affect the size of the next generation. Malaria kills a lot of kids, which is to say there are a lot of potential parents that are going to be saved in places with overtaxed food and water supplies.