In this post in the Bill & Melinda Gates Foundation’s “Impatient Optimists” blog, Megan Averill and Tricia Petruney, senior technical officers with FHI 360’s Global Health, Population and Nutrition Group, and Ward Cates, president emeritus at FHI 360, discuss the “domino effect” of family planning. “We’ll begin with a simple and intuitive causal relationship: voluntary use of contraception prevents unintended pregnancies,” they write, and highlight a number of benefits they say stem from this relationship. They conclude, “Until now, too few people have been aware and too few leaders willing to acknowledge the essential role that family planning plays in achieving sustainable development. Rio+20 is our chance to tip this pivotal domino piece forward, and witness the measurable cascade of progress it evokes” (6/18).