First births to older women continue to rise.

Data from the National Vital Statistics System The first birth rate for women aged 35-39 increased from 1970 to 2006, decreased from 2006 to 2010, and increased again in both 2011 and 2012. The first birth rate for women aged 40-44 was steady in the 1970s and started increasing in the 1980s. The rate more than doubled from 1990 to 2012. For women aged 35-39 and 40-44 all race and Hispanic origin groups had increasing first birth rates from 1990 to 2012. Since 2000, 46 states and DC had an increase in the first birth rate for women aged 35-39. For women aged 40-44, rates increased in 31 states and DC. The average age of women at first birth has risen over the past 4 decades (1-3). This increase is in part a reflection of the shift in first births to women 35 years and older. Delayed childbearing affects the size, composition, and future growth of the population in the United States (2). Increased health risks to older mothers, especially those 40 years and older, and their infants are well documented (4-7), first time older mothers are generally better educated and more likely to have more resources including higher incomes than those at the youngest reproductive ages (8). This report explores trends in first births to women aged 35-39 and 40-44 years from 1970 to 2012, and by race and Hispanic origin from 1990 to 2012 (the most recent year for which comparable data are available). Trends in first births for older women by state are examined for the recent period, 2000 to 2012.