First comes love, then comes baby? That's about right, according to a report from the U.S. Centers for Disease Control and Prevention which found that 27 percent of births between 2003 and 2012 were to unmarried couples that live together. That's a threefold increase in unmarried procreation since 1985. Why such a big boost in babymaking for these cohabitating couples? Experts say it may be the economy: As more couples live together before marriage, kids (planned or unplanned) are more likely to follow.