Sutton Paul D, Hamilton Brady E, Mathews T J
Centers for Disease Control and Prevention's National Center for Health Statistics, Division of Vital Statistics, Reproductive Statistics Branch , Hyattsville, Maryland 20782, USA.
NCHS Data Brief. 2011 Mar(60):1-8.
From 2007 through 2009, birth rates for women aged 15-44 (fertility rates) fell for most states and nearly all major population subgroups. Birth rates declined for all women under age 40 with some of the largest decreases for women in their peak childbearing years. Fertility rates dropped for all major racial and Hispanic groups with the largest declines among Hispanic women. Birth rates by live-birth order also fell with the largest declines for third-order births and progressively smaller declines for second- and first-order births. Fertility rates decreased or were unchanged in every state and the District of Columbia with the largest declines among western and southeastern states. The number of births in the United States reached an all-time high of 4,316,233 in 2007, but that number has since fallen. From 2007 through 2009, births fell 4 percent to 4,131,019; and the provisional count of births through June 2010 indicated continued declines. Fertility rates--which relate the number of births to women aged 15-44 (i.e., the childbearing years)--also fell during this time frame.This report takes a more detailed look at the decline in births from 2007 through 2009 by mother's age, race and ethnicity, birth order, and state. The analysis is based on a comparison of 2007 final and 2009 preliminary birth data from the National Vital Statistics System (NVSS), and are the most current detailed birth data available.
从2007年到2009年，大多数州以及几乎所有主要人口子群体中，15至44岁女性的出生率（生育率）都有所下降。40岁以下所有女性的出生率均下降，其中处于生育高峰期的女性下降幅度最大。所有主要种族和西班牙裔群体的生育率都有所下降，西班牙裔女性下降幅度最大。按生育顺序划分的出生率也下降，三孩出生率下降幅度最大，二孩和一孩出生率下降幅度逐渐减小。每个州以及哥伦比亚特区的生育率都有所下降或保持不变，西部和东南部各州下降幅度最大。2007年美国的出生人数达到创纪录的4316233人，但此后这一数字有所下降。从2007年到2009年，出生人数下降了4%，降至4131019人；2010年6月的临时出生人数统计显示仍在继续下降。在此期间，将出生人数与15至44岁女性（即育龄女性）数量相关联的生育率也有所下降。本报告更详细地审视了2007年至2009年按母亲年龄、种族和族裔、生育顺序以及所在州划分的出生人数下降情况。该分析基于对国家生命统计系统（NVSS）2007年最终出生数据和2009年初步出生数据的比较，这些是目前可获取的最详细的出生数据。
