Most experts recommend mothers breastfeed for six months exclusively after birth – but most women don’t do so. In the U.S.. only 27 percent of mothers reach the 6-month mark. In the U.K., it’s less than one percent. Professor Rafael Pérez-Escamilla of the Yale School of Public Health has been working on a way to boost and sustain breastfeeding rates – and he’s doing it on a country-by-country basis.