Martin Joyce A, Hamilton Brady E, Ventura Stephanie J, Menacker Fay, Park Melissa M, Sutton Paul D
Natl Vital Stat Rep. 2002 Dec 18;51(2):1-102.
This report presents 2001 data on U.S. births according to a wide variety of characteristics. Data are presented for maternal demographic characteristics including age, live-birth order, race, Hispanic origin, marital status, and educational attainment; maternal characteristics (medical risk factors, weight gain, tobacco, and alcohol use); medical care utilization by pregnant women (prenatal care, obstetric procedures, complications of labor and/or delivery, attendant at birth, and method of delivery); and infant characteristics (period of gestation, birthweight, Apgar score, abnormal conditions, congenital anomalies, and multiple births). Also presented are birth and fertility rates by age, live-birth order, race, Hispanic origin, and marital status. Selected data by mother's State of residence are shown, as well as data on month and day of birth, sex ratio, and age of father. Trends in fertility patterns and maternal and infant characteristics are described and interpreted.
Descriptive tabulations of data reported on the birth certificates of the 4.026 million births that occurred in 2001 are presented. Denominators for population-based rates are derived from the 1990 U.S. census. As a result, rates are generally larger than would be the case if 2000-based estimates were used. The magnitude of the overestimate will vary by population subgroup; overestimates are likely greatest for those of Hispanic origin.
The number of births, the birth rate, fertility rate, and total fertility rates all declined 1 percent in 2001. The teenage birth rate reached another historic low. Birth rates for women in their twenties declined slightly, whereas rates for women aged 30 to 44 years continued to rise. Births to unmarried women changed very little. Smoking by pregnant women was down again. Women were more likely to begin care in the first trimester of pregnancy (83.4 percent). The cesarean delivery rate rose for the fifth consecutive year to 24.4 percent; the primary cesarean rate was up 5 percent and the rate of vaginal births after a previous cesarean fell 20 percent. Preterm and low birthweight levels both rose for 2001. The twin birth rate continued to climb, and following 2 years of decline, the rate of triplet/+ births also increased.
本报告呈现了2001年美国各类特征的出生数据。数据涵盖产妇人口统计学特征,包括年龄、生育次序、种族、西班牙裔血统、婚姻状况和教育程度;产妇特征(医疗风险因素、体重增加、吸烟和饮酒情况);孕妇医疗保健利用情况(产前护理、产科手术、分娩并发症、接生人员和分娩方式);以及婴儿特征(妊娠期、出生体重、阿氏评分、异常情况、先天性畸形和多胞胎)。还列出了按年龄、生育次序、种族、西班牙裔血统和婚姻状况划分的出生率和生育率。展示了按母亲居住州选定的数据,以及出生月份和日期、性别比和父亲年龄的数据。描述并解读了生育模式以及母婴特征的趋势。
呈现了2001年402.6万例出生的出生证明上所报告数据的描述性表格。基于人群的比率的分母来自1990年美国人口普查。因此,这些比率通常会比使用基于2000年的估计值时更高。高估的幅度因人群亚组而异;对于西班牙裔血统的人,高估可能最大。
2001年出生人数、出生率、生育率和总生育率均下降了1%。青少年出生率降至另一个历史低点。二十多岁女性的出生率略有下降,而30至44岁女性的出生率继续上升。未婚女性的生育情况变化很小。孕妇吸烟率再次下降。女性更有可能在怀孕的头三个月开始接受护理(83.4%)。剖宫产率连续第五年升至24.4%;初次剖宫产率上升了5%,前次剖宫产术后阴道分娩率下降了20%。2001年早产和低体重水平均有所上升。双胞胎出生率继续攀升,在连续两年下降之后,三胞胎及以上多胞胎出生率也有所增加。