The U.S. birth rate has hit a fresh low, and experts say the poor economy is probably the romance-killing culprit responsible for the decline. Fresh numbers from the Centers for Disease Control and Prevention (CDC) show the nation’s fertility rate slumped to a record low in 2012, with 63.0 births per 1,000 women of childbearing years. That beat the previous all-time low of 63.2 in 2011.