Teenagers age 15 through 19 who are mothers. Rate is per 1,000 females between age 15 and 19.

Teen mother estimates are derived from vital statistics on births to women who were ages 15-19 at the point in time to which each estimate refers: 2005, 2004, 2003, 2002, 2001, or 2000. In order to avoid counting the same mother more than once, only first and not higher-order births were included.

First births to girls ages 14 or younger were excluded from certain estimates because some or all of these girls were not yet 15 years old in a particular year for which we estimated the number of teen mothers. Specifically, we excluded the following first births to girls ages 14 and younger: those occurring in 1999-2002 from the 2003 estimate, those occurring in 1998-2002 from the 2002 estimate, those occurring in 1997-2001 from the 2001 estimate, and those occurring in 1996-2000 from the 2000 estimate. Additionally, we excluded the following first births to girls ages 14 and younger because some or all of these girls were older than 19 in a particular year for which we estimated the number of teen mothers: those occurring in years prior to 1998 from the 2003 estimate, those occurring in years prior to 1997 from the 2002 estimate, those occurring in years prior to 1996 from the 2001 estimate, and those occurring in years prior to 1995 from the 2000 estimate.

Because in any given year the number of teen mothers includes mothers who gave birth in the current year and those who gave birth in prior years, the number of 15 to-year-old mothers at one point in time is substantially greater than the number of births occurring to teens in that year. Because state-level estimates reflect the mother's state of residence at the time of the birth rather than the mother's current state of residence, the state-level statistics do not reflect interstate migration that may have taken place since the time of the birth. However, this is likely to have a small effect on the numbers.