MMWR Surveill Summ. 2013 Nov 29;62(8):1-44.
PROBLEM/CONDITION: Since 1969, CDC has conducted abortion surveillance to document the number and characteristics of women obtaining legal induced abortions in the United States.
Each year, CDC requests abortion data from the central health agencies of 52 reporting areas (the 50 states, the District of Columbia, and New York City). The reporting areas provide this information voluntarily. For 2010, data were received from 49 reporting areas. For the purpose of trend analysis, abortion data were evaluated from the 46 areas that reported data every year during 2001-2010. Census and natality data, respectively, were used to calculate abortion rates (number of abortions per 1,000 women) and ratios (number of abortions per 1,000 live births).
A total of 765,651 abortions were reported to CDC for 2010. Of these abortions, 753,065 (98.4%) were from the 46 reporting areas that provided data every year during 2001-2010. Among these same 46 reporting areas, the abortion rate for 2010 was 14.6 abortions per 1,000 women aged 15-44 years, and the abortion ratio was 228 abortions per 1,000 live births. Compared with 2009, the total number and rate of reported abortions for 2010 decreased 3% and reached the lowest levels for the entire period of analysis (2001-2010); the abortion ratio was stable, changing only 0.4%. From 2001 to 2010, the total number, rate, and ratio of reported abortions decreased 9%, 10%, and 8%, respectively. Given the 3% decrease from 2009 to 2010 in the total number and rate of reported abortions, in combination with the 5% decrease that had occurred in the previous year from 2008 to 2009, the overall decrease for both measures was greater during 2006-2010 than during 2001-2005, despite the annual variations that resulted in no net decrease during 2006-2008. In 2010 and throughout the period of analysis, women in their 20s accounted for the majority of abortions and had the highest abortion rates, whereas women in their 30s and older accounted for a much smaller percentage of abortions and had lower abortion rates. In 2010, women aged 20-24 and 25-29 years accounted for 32.9% and 24.5% of all abortions, respectively, and had abortion rates of 26.7 and 20.2 abortions per 1,000 women aged 20-24 and 25-29 years, respectively. In contrast, women aged 30-34, 35-39, and ≥40 years accounted for 15.3%, 8.9%, and 3.4% of all abortions, respectively, and had abortion rates of 13.2, 7.6, and 2.8 abortions per 1,000 women aged 30-34 years, 35-39 years, ≥40 years, respectively. Throughout the period of analysis, abortion rates decreased among women aged 20-24 and 25-29 years, whereas they increased among women aged ≥40 years. In 2010, adolescents aged 15-19 years accounted for 14.6% of all abortions and had an abortion rate of 11.7 abortions per 1,000 adolescents aged 15-19 years. Throughout the period of analysis, the percentage of all abortions accounted for by adolescents and the adolescent abortion rate decreased. In contrast to the percentage distribution of abortions and abortion rates by age, abortion ratios in 2010 and throughout the entire period of analysis were highest among adolescents and lowest among women aged 30-39 years. Abortion ratios decreased from 2001 to 2010 for women in all age groups except for those aged <15 years, for whom they increased. In 2010, most (65.9%) abortions were performed at ≤8 weeks' gestation, and 91.9% were performed at ≤13 weeks' gestation. Few abortions (6.9%) were performed at 14-20 weeks' gestation, and even fewer (1.2%) were performed at ≥21 weeks' gestation. From 2001 to 2010, the percentage of all abortions performed at ≤8 weeks' gestation increased 10%, whereas the percentage performed at >13 weeks' decreased 10%. Moreover, among abortions performed at ≤13 weeks' gestation, the distribution shifted toward earlier gestational ages, with the percentage of these abortions performed at ≤6 weeks' gestation increasing 36%. In 2010, a total of 72.4% of abortions were performed by curettage at ≤13 weeks' gestation, 17.7% were performed by early medical abortion (a nonsurgical abortion at ≤8 weeks' gestation), and 8.3% were performed by curettage at >13 weeks' gestation. Among abortions that were performed at ≤8 weeks' gestation, and thus were eligible for early medical abortion on the basis of gestational age, 26.5% were completed by this method. From 2009 to 2010, the use of early medical abortion increased 13%. Deaths of women associated with complications from abortions for 2010 are being investigated under CDC's Pregnancy Mortality Surveillance System. In 2009, the most recent year for which data were available, eight women were identified to have died as a result of complications from known legal induced abortions. No reported deaths were associated with illegal induced abortions.
Among the 46 areas that reported data every year during 2001-2010, the gradual decrease that had occurred during previous decades in the total number and rate of reported abortions continued through 2005, whereas year-to-year variation from 2006 to 2008 resulted in no net change during this later period. However, the large decreases that occurred both from 2008 to 2009 and from 2009 to 2010 resulted in a greater overall decrease during 2006-2010 as compared with 2001-2005 and the lowest number and rate of reported abortions for the entire period of analysis.
Unintended pregnancy is the major contributor to abortion. Because unintended pregnancies are rare among women who use the most effective methods of reversible contraception, increasing access to and use of these methods can help further reduce the number of abortions performed in the United States. The data in this report can help program planners and policy makers identify groups of women at greatest risk for unintended pregnancy and help guide and evaluate prevention efforts.
问题/状况：自 1969 年以来，疾病预防控制中心一直对堕胎进行监测，以记录在美国进行合法人工流产的女性数量和特征。
2010 年。
每年，疾病预防控制中心都从 52 个报告地区（50 个州、哥伦比亚特区和纽约市）的中央卫生机构请求堕胎数据。这些报告地区自愿提供这些信息。在 2010 年，收到了 49 个报告地区的数据。为了进行趋势分析，从 2001-2010 年每年都报告数据的 46 个报告地区评估了堕胎数据。分别使用人口普查和出生率数据来计算堕胎率（每 1000 名 15-44 岁妇女的堕胎数）和比率（每 1000 名活产婴儿的堕胎数）。
疾病预防控制中心共收到 2010 年的 765651 例堕胎报告。其中，753065 例（98.4%）来自 46 个报告地区，这些地区在 2001-2010 年期间每年都提供数据。在这 46 个相同的报告地区中，2010 年的堕胎率为每 1000 名 15-44 岁妇女 14.6 例，堕胎比为每 1000 名活产婴儿 228 例。与 2009 年相比，2010 年报告的总堕胎数和堕胎率分别下降了 3%，达到整个分析期间（2001-2010 年）的最低水平；堕胎比保持稳定，仅变化 0.4%。从 2001 年到 2010 年，报告的堕胎总数、率和比分别下降了 9%、10%和 8%。鉴于 2009 年至 2010 年报告的堕胎总数和率下降了 3%，再加上前一年 2008 年至 2009 年下降了 5%，与 2001 年至 2005 年相比，这两个指标在 2006-2010 年期间的降幅更大，尽管这两年的年度变化导致 2006-2008 年期间没有净减少。在 2010 年和整个分析期间，20 多岁的女性占堕胎总数的大部分，堕胎率最高，而 30 多岁和年龄更大的女性占堕胎总数的比例要小得多，堕胎率也较低。2010 年和整个分析期间，年龄在 20-24 岁和 25-29 岁的女性分别占所有堕胎的 32.9%和 24.5%，堕胎率分别为每 1000 名 20-24 岁和 25-29 岁女性 26.7 和 20.2 例。相比之下，年龄在 30-34 岁、35-39 岁和≥40 岁的女性分别占所有堕胎的 15.3%、8.9%和 3.4%，堕胎率分别为每 1000 名 30-34 岁、35-39 岁和≥40 岁女性 13.2、7.6 和 2.8 例。在整个分析期间，20-24 岁和 25-29 岁的女性堕胎率下降，而≥40 岁的女性堕胎率上升。2010 年，15-19 岁的青少年占所有堕胎的 14.6%，青少年的堕胎率为每 1000 名 15-19 岁青少年 11.7 例。在整个分析期间，青少年的堕胎比例和青少年的堕胎率都有所下降。与年龄的堕胎比例和堕胎率的分布相反，2010 年和整个分析期间，堕胎率在青少年中最高，在 30-39 岁的女性中最低。除了<15 岁的女性，她们的堕胎率增加外，从 2001 年到 2010 年，所有年龄组的堕胎率都有所下降。在 2010 年，大多数（65.9%）堕胎发生在≤8 周妊娠时，91.9%发生在≤13 周妊娠时。很少有（6.9%）堕胎发生在 14-20 周妊娠时，甚至更少（1.2%）发生在≥21 周妊娠时。从 2001 年到 2010 年，≤8 周妊娠的所有堕胎百分比增加了 10%，而>13 周妊娠的堕胎百分比减少了 10%。此外，在≤13 周妊娠时进行的堕胎中，分布向更早的妊娠龄转移，≤6 周妊娠的堕胎百分比增加了 36%。2010 年，在≤13 周妊娠时，72.4%的堕胎通过刮宫术进行，17.7%通过早期药物流产（≤8 周妊娠的非手术流产）进行，8.3%通过>13 周妊娠时的刮宫术进行。在≤8 周妊娠且因此符合早期药物流产的情况下，26.5%的堕胎采用这种方法完成。从 2009 年到 2010 年，早期药物流产的使用增加了 13%。疾病预防控制中心的妊娠死亡率监测系统正在调查与 2010 年堕胎相关的妇女死亡情况。在 2009 年，即可获得数据的最近一年，有 8 名妇女被确定因已知的合法人工流产而死亡。没有报告与非法人工流产有关的死亡。
在 2001-2010 年期间每年都报告数据的 46 个地区中，前几十年堕胎总数和堕胎率持续下降的趋势一直持续到 2005 年，而 2006-2008 年的年度变化导致在此期间没有净变化。然而，2008-2009 年和 2009-2010 年的大幅下降导致 2006-2010 年的总体下降幅度大于 2001-2005 年，以及整个分析期间堕胎总数和堕胎率达到最低水平。
意外怀孕是堕胎的主要原因。由于意外怀孕在使用最有效的可逆避孕方法的女性中很少见，因此增加这些方法的可及性和使用率可以进一步减少美国堕胎的数量。本报告中的数据可以帮助规划人员和政策制定者识别最容易意外怀孕的妇女群体，并有助于指导和评估预防工作。
