There are more than 4 million babies born each year in the United States alone. That’s a lot of diapers, baby wipes, and formula. But where, exactly, are all these new Americans born? Are some cities more fertile than others? To find the cities where partners are most likely to produce new offspring in 2012, we first accounted for the percentage of women age 15-50 who gave birth in each metropolitan area, using 2008-2010 summary data from the U.S. Census. We also looked at for four factors that can affect fertility as identified by the National Institutes of Health: alcohol and tobacco use (for men and women), women’s health (measured by the percent of women who have had a Pap test in the past three years), and the general health of each metropolitan area’s population, with 2010 data from the Centers for Disease Control and Prevention Behavioral Risk Factor Surveillance System. Looking at more than 150 metropolitan areas for which full data was available, we identified the nation’s 25 most fertile cities. The metro areas that had a high percentage of births, lowest alcohol and tobacco use, and the best women’s and overall health, ranked highest.