Ely Danielle M, Hamilton Brady E
NCHS Data Brief. 2018 Oct(323):1-8.
Since the most recent peak in the total fertility rate (the estimated number of lifetime births expected per 1,000 women) in 2007, the United States has experienced a decreasing total fertility rate and an increasing mean, or average, age of mothers at first birth (1-4). Previous research shows rural areas have persistently higher fertility and worse birth outcomes compared with metropolitan (metro) areas (2,5-8). This report describes trends and differences in total fertility rates and mean maternal age at first birth overall, and by race and Hispanic origin, between rural and small or medium metro, and rural and large metro counties, from 2007 through 2017.
自2007年总生育率（每1000名女性预期终身生育的估计数量）达到最近峰值以来，美国的总生育率持续下降，首次生育的母亲平均年龄不断上升（1 - 4）。此前的研究表明，与大都市地区相比，农村地区的生育率一直较高，出生结果也更差（2,5 - 8）。本报告描述了2007年至2017年期间，农村与中小都市以及农村与大都市大县之间，总体以及按种族和西班牙裔血统划分的总生育率和首次生育的平均母亲年龄的趋势和差异。
