Just read the part about breast feeding in Jared Diamond's latest book on traditional societies. Interestingly apparently most traditional societies use on demand feeding, the baby is always within reach of the breast and can drink whenever it wants. The average seems to be that the mom still wakes twice a night, but the baby drinks 14 times, most of the time without even waking the mother.

I suppose it would be difficult with modern beds because I suppose most mothers have some sort of pads on their breast to avoid lactating into the mattress.