Births: preliminary data for 2001.

OBJECTIVES: This report presents preliminary data for 2001 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, prenatal care, cesarean delivery, and low birthweight are also presented. METHODS: Data in this report are based on more than 96 percent of births for 2001. The records are weighted to independent control counts of all births received in State vital statistics offices in 2001. Comparisons are made with 2000 final data. RESULTS: The number of births, the crude birth rate, and the fertility rate all declined slightly between 2000 and 2001. The number of births was down by less than 1 percent, the crude birth rate declined 1 percent to 14.5 per 1,000 population, and the fertility rate was down slightly to 67.2 births per 1,000 women aged 15-44 years. Teenagers were less likely to give birth in 2001; the teen birth rate continued to fall, dropping 5 percent between 2000 and 2001 to 45.9 births per 1,000 females aged 15-19 years, another record low. The teen birth rate has fallen 26 percent since 1991. The birth rate for teenagers 15-17 years fell 8 percent, and the rate for teenagers 18-19 years was down 4 percent for 2000-2001. Since 1991 rates have fallen 35 percent for teenagers 15-17 years, and 20 percent for teenagers 18-19 years. Birth rates for women aged 20-24 declined by 2 percent, whereas rates for women 25-44 years increased. Childbearing among women aged 40-54 years was stable. The birth rate for unmarried women decreased modestly to 44.9 births per 1,000 unmarried women 15-44 years in 2001, still remaining below the peak reached in 1994. The number of births to unmarried women was up very slightly, but births to unmarried teens were down. The proportion of women who began prenatal care in the first trimester of pregnancy improved slightly to 83.4 percent, but the rate of low birthweight held at 7.6 percent. The total cesarean delivery rate jumped 7 percent between 2000 and 2001 to 24.4 percent of all births, the highest level ever reported from this data source; the primary rate of cesarean deliveries rose 5 percent, and the rate of vaginal births after previous cesarean delivery tumbled 20 percent.     

Births: preliminary data for 2002.

OBJECTIVES: This report presents preliminary data for 2002 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, prenatal care, cesarean delivery, preterm births, and low birthweight are also presented. METHODS: Data in this report are based on nearly 98 percent of births for 2002. The records are weighted to independent control counts of all births received in State vital statistics offices in 2002. Comparisons are made with 2001 final data. RESULTS: The crude birth rate was 13.9 per 1,000 population in 2002, a decrease of 1 percent from 2001 (14.1). This is the lowest birth rate reported for the United States since national data have been available. The fertility rate was also down 1 percent in 2002 to 64.8 births per 1,000 women aged 15-44 years. Since 1990, this rate has declined 9 percent. The birth rate for teenagers continued to decline in 2002, dropping 5 percent to 42.9 births per 1,000 women aged 15-19 years. The teenage birth rate has dropped 28 percent since 1990. The rate for younger teenagers 15-17 years fell 6 percent from 24.7 per 1,000 in 2001 to 23.2 in 2002. The rate for older teenagers 18-19 years declined 4 percent from 76.1 per 1,000 in 2001 to 72.7 in 2002. Since 1990, the rate for teenagers 15-17 years has fallen 38 percent and the rate for teenagers 18-19 years, 18 percent. The birth rate for women aged 20-24 years declined by 3 percent to 103.5 per 1,000 in 2002 compared with 2001, whereas the rate for women aged 25-29 years was essentially unchanged (113.6). The birth rate for women aged 30-34 years decreased slightly from 91.9 per 1,000 in 2001 to 91.6 in 2002. Birth rates for women aged 35-39 years and 40-44 years continued to rise, increasing 2 percent for both. Childbearing among women over 45 years of age was unchanged. The birth rate for unmarried women was down slightly in 2002 to 43.6 births per 1,000 unmarried women aged 15-44 years. The number of births to unmarried women increased by 1 percent in 2002; however births to unmarried teenagers declined by 4 percent. Prenatal care utilization continued to slowly but steadily improve; 83.8 percent of women began prenatal care in the first trimester of pregnancy in 2002 compared with 83.4 in 2001. More than one fourth of all births (26.1 percent) were cesarean deliveries in 2002, the highest rate ever reported in the United States; the primary cesarean rate jumped 7 percent to 18 percent and the rate of vaginal births after previous cesarean delivery plummeted 23 percent to 12.7 percent (figure 1). Preterm (12.0 percent) and low birthweight (7.8 percent) rates were up slightly for 2002. The low birthweight rate is the highest reported in more than three decades.     

Births: preliminary data for 2005.

OBJECTIVES: This report presents preliminary data for 2005 on births in the United States. U.S. data on births are shown by age, live-birth order, race, and Hispanic origin of mother. Data on marital status, cesarean delivery, preterm births, and low birthweight (LBW) are also presented. METHODS: Data in this report are based on 99.2 percent of births for 2005. The records are weighted to independent control counts of all births received in state vital statistics offices in 2005. Comparisons are made with 2004 data. RESULTS: The crude birth rate in 2005 was 14.0 births per 1,000 total population, unchanged from 2004. The general fertility rate, however, rose to 66.7 births per 1,000 women aged 15-44 years in 2005, the highest level since 1993. The birth rate for teenagers declined by 2 percent in 2005, falling to 40.4 births per 1,000 women aged 15-19 years, the lowest ever recorded in the 65 years for which a consistent series of rates are available. The rate declined for teenagers 15-17 years to 21.4 births per 1,000, but was essentially stable for older teenagers 18-19 years. The birth rate for women aged 20-24 years rose in 2005, whereas the rate for women aged 25-29 years was essentially unchanged. The birth rates for women aged 30 years and over rose to levels not seen in almost 40 years. Childbearing by unmarried women increased to record levels for the Nation in 2005. The birth rate rose 3 percent to 47.6 births per 1,000 unmarried women aged 15-44 years; the proportion of all births to unmarried women increased to 36.8 percent. The cesarean delivery rate rose by 4 percent in 2005 to 30.2 percent of all births, another record high for the Nation. The preterm birth rate continued to rise (to 12.7 percent in 2005) as did the rate for LBW births (8.2 percent).     

Births: preliminary data for 2004.

OBJECTIVES: This report presents preliminary data for 2004 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, tobacco use, prenatal care, cesarean delivery, preterm births, and low birthweight (LBW) are also presented. METHODS: Data in this report are based on 99.1 percent of births for 2004. The records are weighted to independent control counts of all births received in State vital statistics offices in 2004. Comparisons are made with 2003 data. RESULTS: The crude birth rate declined 1 percent to 14.0 births per 1,000 population. The fertility rate, however, rose slightly to 66.3 births per 1,000 women aged 15-44 years. Birth rates for teenagers 15-19 years declined modestly. The rate in 2004 was 41.2 births per 1,000 females aged 15-19 years, 1 percent lower than in 2003. Rates declined 1 percent each for teenagers 15-17 and 18-19 years. The rate for 10-14 year-olds increased slightly. The birth rate for women aged 20-24 years declined 1 percent to 101.8, a record low for the Nation. The rate for women aged 25-29 years remained essentially unchanged at 115.5 per 1,000. The birth rate for women aged 30-34 years rose less than 1 percent to 95.5 per 1,000, whereas the rates for women aged 35-39 and 40-44 years increased 3 to 4 percent each. The rate for women aged 45-49 years rose to 0.6 per 1,000. Childbearing by unmarried women rose to a record high of almost 1.5 million births in 2004, a 4-percent increase from 2003. The proportion of all births to unmarried women increased to 35.7 percent. Smoking during pregnancy declined slightly in 2004, to 10.2 percent of mothers in the 40-State reporting area. There was no improvement in timely receipt of prenatal care. In 2004, 83.9 percent of mothers in the 41-State reporting area began care in the first trimester. A record high cesarean delivery rate was reported in 2004, at 29.1 percent of all births, a 6-percent increase from 2003. The primary cesarean rate rose 8 percent, whereas the rate of vaginal birth after cesarean delivery declined 13 percent. Preterm and LBW rates each increased in 2004. More than 500,000 infants were born preterm, a rate of 12.5 percent. The LBW rate increased to 8.1 percent.     

Births: preliminary data for 2003.

OBJECTIVES: This report presents preliminary data for 2003 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, tobacco use, prenatal care, cesarean delivery, preterm births, and low birthweight are also presented. METHODS: Data in this report are based on nearly 99 percent of births for 2003. The records are weighted to independent control counts of all births received in State vital statistics offices in 2003. Comparisons are made with 2002 final data. RESULTS: The crude birth rate rose to 14.1 births per 1000 population in 2003, an increase of 1 percent from 2002 (13.9). The fertility rate also rose in 2003 by 2 percent to 66.1 births per 1000 women aged 15-44 years. Since 1994, the rate has ranged from 63.6 to 66.1. The birth rate for teenagers continued to decline in 2003 to 41.7 births per 1000 women aged 15-19 years, 3 percent lower than in 2002. Rates fell for teenagers in all race and Hispanic origin groups, in many cases marking new record lows for the Nation. Birth rates for teenagers 15-17 and 18-19 years continued to steadily decline. The rate for ages 15-17 was 22.4 per 1000 in 2003, down 3 percent from 2002 and 42 percent from 1991, the recent peak. The rate for older teenagers 18-19 years in 2003 was 70.8 per 1000, also 3 percent lower than in 2002 and 25 percent lower than in 1991. The birth rates for women in their twenties were 102.6 per 1000 for women aged 20-24 years and 115.7 for women aged 25-29 years, a decrease of 1 percent and an increase of 2 percent, respectively, compared with 2002. The birth rate for women aged 30-34 years increased 4 percent to 95.2 births per 1000 women compared with 2002. The rate rose 6 percent for women aged 35-39 years, between 2002 and 2003, and 5 percent for women aged 40-44 years. The rate for women aged 45-49 years remained unchanged. The birth rate for unmarried women increased by 3 percent in 2003, from 43.7 to 44.9 per 1000 unmarried women aged 15-44 years. The proportion of births to unmarried women also increased in 2003 to 34.6 percent, compared with 34.0 percent in 2002. The proportion of mothers smoking during pregnancy continued to steadily decline in 2003, from 11.4 percent in 2002 to 11.0 percent. The percent of women who received prenatal care within the first 3 months of pregnancy edged upward for 2003, to 84.1 percent, compared with 83.7 percent in 2002. In 2003, 27.6 percent of all births were delivered by cesarean delivery, a marked rise of 6 percent over the 2002 level, and one-third higher than that for 1996. The primary cesarean rate also rose 6 percent between 2002 and 2003 while the rate of vaginal birth after previous cesarean (VBAC) dropped by 16 percent. Preterm and low birthweight rates both rose between 2002 and 2003. The preterm rate increased from 12.1 to 12.3 and low birthweight rate rose from 7.8 to 7.9 percent.     

Births: preliminary data for 2000.

OBJECTIVES: This report presents preliminary data for 2000 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, prenatal care, cesarean delivery, and low birthweight are also presented. METHODS: Data in this report are based on more than 96 percent of births for 2000. The records are weighted to independent control counts of births received in State vital statistics offices in 2000. Comparisons are made with 1999 final data. RESULTS: The number of births rose 3 percent between 1999 and 2000. The crude birth rate increased to 14.8 per 1,000 population in 2000, 2 percent higher than the 1999 rate. The fertility rate rose 3 percent to 67.6 per 1,000 women aged 15-44 years between 1999 and 2000. The birth rate for teenagers, which has been falling since 1991, declined 2 percent in 2000 to 48.7 births per 1,000 females aged 15-19 years, another historic low. The rate for teenagers 15-17 years fell 4 percent, and the rate for 18-19 year olds was down 1 percent. Since 1991, rates have fallen 29 percent for teenagers 15-17 years and 16 percent for teenagers 18-19 years. Birth rates for all of the older age groups increased for 1999-2000: 1 percent among women aged 20-24 years, 3 percent for women aged 25-29 years, and 5 percent for women in their thirties. Rates for women aged 40-54 years were also up for 2000. The birth rate for unmarried women increased 2 percent to 45.2 births per 1,000 unmarried women aged 15-44 years in 2000, but was still lower than the peak reached in 1994. The number of births to unmarried women was up 3 percent, the highest number ever reported in the United States. However, the number of births to unmarried teenagers declined. The proportion of women who began prenatal care in the first trimester of pregnancy (83.2 percent) did not improve for 2000, nor did the rate of low birthweight (7.6 percent). The total cesarean rate rose for the fourth consecutive year to 22.9 percent, the result of both a rise in the rate of primary cesarean deliveries and a decline in the rate of vaginal births after previous cesarean delivery.     

Births: preliminary data for 1999.

OBJECTIVES: This report presents preliminary data for 1999 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, prenatal care, cesarean delivery, and low birthweight are also presented. METHODS: Data in this report are based on more than a 97-percent sample of births for 1999. The records are weighted to independent control counts of births received in State vital statistics offices in 1999. Comparisons are made with 1998 final data. RESULTS: The crude birth rate in 1999 was 14.5 per 1,000 population, a slight decline from 1998 (14.6), returning to the level observed in 1997. However, the fertility rate, which is limited to women aged 15-44 years, was 65.8 in 1999, a slight increase over the rate for 1998 (65.6). The birth rate for teenagers continued to decline for 1998-99, dropping 3 percent to 49.6 births per 1,000 females aged 15-19 years. The 1999 rate for teenagers is 20 percent lower than the recent high point in 1991. The rate for young teenagers 15-17 years fell 6 percent, and the rate for teenagers 18-19 years declined 2 percent. Since 1991, rates have fallen 26 percent for teenagers 15-17 years, and 15 percent for teenagers 18-19 years. Birth rates for women aged 20-24 years declined slightly between 1998 and 1999 whereas the rate for women aged 25-29 years rose 2 percent. Birth rates for women in their thirties and forties continued their long increase. Rates for women in their thirties increased 2 to 3 percent and were the highest in three decades. The birth rate for women aged 40-44 years was the highest level reported since 1970. The birth rate for unmarried women in 1999 was 43.9 per 1,000, 1 percent lower than in 1998 and 6 percent lower than the peak level reported for 1994 (46.9). However, the number of births to unmarried women was up about 1 percent due to the continued increase in the number of unmarried women of childbearing age. The rate of prenatal care utilization continued to improve. The total cesarean rate increased 4 percent between 1998 and 1999 and continued a 3-year rise. The low birthweight rate remained unchanged at 7.6 percent.     

Trends in cesarean rates for first births and repeat cesarean rates for low-risk women: United States, 1990-2003.

OBJECTIVES: This report presents trends in cesarean rates for first births and repeat cesarean rates for low-risk women, in relation to the Healthy People 2010 (HP 2010) objectives. Data for the U.S. showing trends by maternal age and race and Hispanic origin are presented. METHODS: Cesarean rates were computed based on the information reported on birth certificates. RESULTS: With a decrease between 1990 and 1996 and an increase between 1996 and 2003, the trend in the cesarean rate for low-risk women having a first birth paralleled trends in the primary (regardless of parity) and total cesarean rates. During 1996-2003 the cesarean rate for low-risk women having a first birth has consistently been at least 13 percent lower than the rate for all women having a first birth. For 2003 the cesarean rate for all primiparous women was 27.1 percent; for low-risk women the rate was 23.6 percent. The trend in the repeat cesarean rate for low-risk women was similar to the trend in the repeat rate for all women, i.e., a decrease from 1990 to 1996 and an increase from 1996 to 2003. The repeat cesarean rate for low-risk women has consistently been slightly lower than the rate for all women. For 2003 the repeat rate for all women was 89.4; the rate for low-risk women was 88.7. These trends were found for low-risk women of all ages and racial or ethnic groups. Therefore, low-risk women giving birth for the first time who have a cesarean delivery are more likely to have a subsequent cesarean delivery.     

Trends in cesarean birth and vaginal birth after previous cesarean, 1991-99.

OBJECTIVES: This report presents trends in rates of cesarean delivery and rates of vaginal birth after previous cesarean (VBAC) delivery for 1991-99. Data for the United States showing trends by maternal age, race/ethnicity, and State are presented. Also trends in cesarean rates by selected maternal characteristics, medical risk factors, and complications of labor and/or delivery are shown. A brief explanation of the Healthy People 2010 objective regarding cesarean and VBAC rates for low-risk women is also included. Summary statistics for 2000 based on preliminary data are also included, but most tabular and text information is based on detailed final statistics for 1999. METHODS: Cesarean and VBAC rates were computed based on the information reported on birth certificates. RESULTS: The U.S. cesarean rate dropped 8 percent between 1991 and 1996 (from 22.6 to 20.7 per 100 births) but then increased 6 percent between 1996 and 1999 (to 22.0); preliminary data show that the rate increased again by 4 percent between 1999 and 2000 (to 22.9). The decline between 1991 and 1996 was present for women of all ages but was most pronounced for those under 30 years of age. The decline was greatest for non-Hispanic white women, 10 percent, compared with a 7-percent decline for Hispanic women and only a 1-percent decline for non-Hispanic black women. All groups experienced increases in cesarean rates of about 6 to 7 percent between 1996 and 1999. The increase in cesarean rates between 1996 and 1999 was greatest for women 30 years of age and over. The VBAC rate increased 33 percent between 1991 and 1996 (from 21.3 to 28.3 per 100 births to women with a previous cesarean) but then fell 17 percent between 1996 and 1999 (to 23.4). The dramatic increase in VBAC rates between 1991 and 1996, followed by the subsequent decline, was experienced by women of all ages and for each major race/ethnicity group. Similar trends in cesarean rates were present for nearly all States and for most medical risk factors and complications of labor and/or delivery.     

Trends and differentials in higher-birthweight infants at 28–31 weeks of gestation, by race and Hispanic origin, United States, 1990–2002

Birth certificate gestational age data based on the date of the mother's last menstrual period (LMP) are considered problematic. Of particular concern are birthweight distributions for infants reported on the birth certificate as having been delivered at 28–31 weeks' gestation; these distributions have been shown to be distinctly bimodal. The 'second curve' of the birthweight distribution at 28–31 weeks includes implausible birthweight/gestational age combinations and, thus, has been hypothesised to represent erroneous gestational ages due to misidentification of the date of LMP. It has been suggested that such 'misclassification' has declined in recent years and that this change can affect trends in preterm birth rates (<37 weeks' gestation), particularly rates among non-Hispanic black infants. This present study used primarily simple and multivariable analyses to review trends and differentials in birthweight distributions at 28–31 weeks by race and Hispanic origin of the mother. It aggregated data for the years 1990–92 and 2000–02 from the US vital statistics Natality files.
Over the decade, the percentage of births in the second curve declined for all births and for each racial and Hispanic origin group studied. The largest decline was observed for non-Hispanic blacks; the smallest for Hispanic births. Later initiation of prenatal care, younger maternal age, lower educational attainment, higher birth order and vaginal and singleton delivery were positively associated with a larger second curve, suggesting misclassification of gestational age. Declines in the second curve over the study period were suggested to contribute significantly to the observed decrease in overall preterm birth rates for non-Hispanic black births. Further analysis is needed to estimate the influence of reporting error on preterm birth rates by race and Hispanic origin.