Biomedical subjects

Stephanie J Ventura

Publications and source records attributed to Stephanie J Ventura.

16 recordsLinked to original sources

PubMed2006

Births: final data for 2004.

OBJECTIVES: This report presents 2004 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 lifestyle and health characteristics (medical risk factors, weight gain, and tobacco use); medical care utilization by pregnant women (prenatal care, obstetric procedures, characteristics of labor and/or delivery, attendant at birth, and method of delivery); and infant characteristics (period of gestation, birthweight, Apgar score, 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. METHODS: Descriptive tabulations of data reported on the birth certificates of the 4.1 million births that occurred in 2004 are presented. Denominators for population-based rates are post-censal estimates derived from the U.S. 2000 census. RESULTS: In 2004, 4,112,052 births were registered in the United States, less than 1 percent more than the number in 2003. The crude birth rate declined slightly; the general fertility rate increased by less than 1 percent. Childbearing among teenagers and women aged 20-24 years declined to record lows. Rates for women aged 25-34 and 45-49 years were unchanged, whereas rates for women aged 35-44 years increased. All measures of unmarried childbearing rose in 2004. Smoking during pregnancy continued to decline. No improvement was seen in the timely initiation of prenatal care. The cesarean delivery rate jumped 6 percent to another all-time high, whereas the rate of vaginal birth after previous cesarean fell by 13 percent. Preterm and low birthweight rates continued their steady rise. The twinning rate increased, but the rate of triplet and higher order multiple births was down slightly.

Adolescent↗

PubMed2006

Fertility and abortion rates in the United States, 1960-2002.

This paper provides a general overview of trends in the United States (US) birth, fertility and abortion data from 1960 to 2002. Rates by age, race and Hispanic origin are also discussed. Data presented in this paper are derived primarily from published reports of the US government's Centers for Disease Control and Prevention's National Center for Health Statistics. In 2002, there were 4,021,726 births in the US. The general fertility rate was 64.8 births per 1,000 women aged 15-44 years, the total fertility rate was 2013.0 children per 1,000 women, and the net reproduction rate was 968 daughters per 1000 women. These rates have declined in the US since 1960, down by at least 44% for all rates. While these rates have been declining, there are substantial differences in fertility patterns by age and race and Hispanic origin. Rates for women, 30 years of age and over, increased between 1980 and 2002. In contrast, rates for women under 25 years of age rose considerably during the late 1980s, and then decreased sharply since 1991. Rates for women in their late twenties (25-29 years of age), the principal childbearing ages, have fluctuated within a narrow range throughout this period (1980-2002). As a result of the increase in births to older women, the mean age of mother at first birth increased by nearly 4 years from 1968 to 2002. In 2000, the latest year for which data are available, there were 21.3 induced abortions per 1000 women aged 15-44 years, down from 27.4 in 1990. The total abortion rate, average number of legally induced abortions that would occur to a hypothetical cohort of 1000 women, was 672.0 abortions per 1,000 women in 2000, down from 785.5 in 1980. The abortion rate has declined fairly steadily since 1980. Like the birth and fertility rates, substantial differences in abortion rates exist by age and race and Hispanic origin. The rates of induced abortion increased for women in their thirties between 1980 and 2000, whereas rates for women under 25 years of age and women 40 years of age and over decreased since 1980. The rate for women 25-29 years of age changed little. The rate of induced abortion was considerably higher for non-Hispanic black women (57.4) in 2000 than for non-Hispanic white women (11.7). The rate for Hispanic women (30.6) was intermediate. The total abortion rate was also much higher for non-Hispanic black women than non-Hispanic white and Hispanic women.

Abortion, Induced↗

PubMed2005

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.

Adolescent↗

PubMed2005

Births: final data for 2003.

OBJECTIVES: This report presents 2003 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, and 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. METHODS: Descriptive tabulations of data reported on the birth certificates of the 4.09 million births that occurred in 2003 are presented. Denominators for population-based rates are derived from the U.S. 2000 census. RESULTS: In 2003 there were 4,089,950 live births reported in the United States, 2 percent more than the number in 2002. The crude birth rate (CBR) and general fertility rate (GFR) rose slightly. Childbearing among teenagers declined for the 12th straight year to another historic low. Birth rates for women aged 20-24 years also declined, whereas rates for women aged 25-44 years increased 2-6 percent, reaching highs not reported since the mid- to late 1960s. All measures of unmarried childbearing increased considerably in 2003, but smoking during pregnancy continued to decline. Timely initiation of prenatal care improved slightly. The cesarean delivery rate jumped another 5 percent to another all-time high, and the rate of vaginal birth after previous cesarean dropped 16 percent, an all-time low. Key measures of birth outcome-the percentages of preterm and low birthweight (LBW) births-rose. The twinning rate increased, but the rate of triplet and higher order multiple births was essentially stable.

Adolescent↗

PubMed2005

Explaining the 2001-02 infant mortality increase: data from the linked birth/infant death data set.

The U.S. infant mortality rate increased from 6.8 infant deaths per 1,000 live births in 2001 to 7.0 in 2002, the first increase in more than 40 years. From 2001 to 2002 infant mortality rates increased for very low birthweight infants as well as for preterm and very preterm infants. Although infant mortality rates for very low birthweight infants increased, most of the increase in the infant mortality rate from 2001 to 2002 was due to a change in the distribution of births by birthweight and, more specifically, to an increase in infants born weighing less than 750 grams (1 lb 10 1/2 oz). The majority of infants born weighing less than 750 grams die within the first year of life; thus, these births contribute disproportionately to the overall infant mortality rate. Increases in births at less than 750 grams occurred for non-Hispanic white, non-Hispanic black, and Hispanic women. Most of the increase occurred among mothers 20-34 years of age. Although multiple births contributed disproportionately, most of the increase in births at less than 750 grams occurred among singletons. Three hypotheses were evaluated to assess their possible impact on the increase in less than 750-gram births: first, possible changes in the reporting of births or fetal deaths; second, possible changes in the risk profile of births; and third, possible changes in medical management of pregnancy. Although each of these factors may have contributed to the increase, the relative effects of these and other factors remain unclear. More-detailed studies are needed to further explain the 2001-02 infant mortality increase.

Birth Weight↗

PubMed2005

Explaining the 2001-2002 infant mortality increase in the United States: data from the linked birth/infant death data set.

The U.S. infant mortality rate (IMR) increased from 6.8 infant deaths per 1,000 live births in 2001 to 7.0 in 2002, the first increase in more than 40 years. From 2001 to 2002, IMR increased for very low birthweight infants as well as for preterm and very preterm infants. Although IMR for very low birthweight infants increased, most of the increase in IMR from 2001 to 2002 was due to a change in the distribution of births by birthweight and, more specifically, to an increase in infants born weighing less than 750 grams. The majority of infants born at less than 750 grams die within the first year of life; thus, these births contribute disproportionately to overall IMR. Increases in births at less than 750 grams occurred fornon-Hispanic white, non-Hispanic black, and Hispanic women. Most of the increase occurred among mothers 20 to 34 years of age. Although multiple births contributed disproportionately, most of the increase in births at less than 750 grams occurred among singletons. Three hypotheses were evaluated to assess their possible impact on the increase in less than 750-gram births: possible changes in (1) the reporting of births or fetal deaths, (2) the risk profile of births, and (3) medical management of pregnancy. Although each of these factors may have contributed to the increase, the relative effects of these and other factors remain unclear. More detailed studies are needed to further explain the 2001-2002 infant mortality increase.

Birth Rate↗

PubMed2004

Births to 10-14 year-old mothers, 1990-2002: trends and health outcomes.

OBJECTIVES: This report presents the number and rate of U.S. births for 10-14 year olds, for 1990-2002 by race and Hispanic origin and by State. Pregnancy risk factors and outcomes by selected maternal and infant characteristics are shown. METHODS: Tabular and graphical descriptions of births and infant deaths to 10-14 year olds are presented based on information reported on birth and death certificates for the United States and each State. RESULTS: 7,315 females aged 10-14 years delivered a live birth in 2002. The rate of births to 10-14 year olds was 0.7 per 1,000 in 2002, half of the rate during 1989-94. This rate peaked in 1989 (1.4 per 1,000). For 1990-94 the rate remained at 1.4, and then began a steady decline to 0.7 per 1,000 in 2002. Large declines in young teenage childbearing were seen among all racial and ethnic subgroups, as well as almost all States. These young mothers were least likely to receive timely prenatal care compared with mothers of older age groups. Compared with infants of mothers aged 20-39 years, infants of the youngest mothers experienced almost twice the rates of preterm delivery (21.3 percent) and low birthweight (12.6 percent). The infant mortality rate (15.4 per 1,000) was two to three times higher than that for infants of mothers aged 20-44 years.

Adolescent↗

PubMed2004

Estimated pregnancy rates for the United States, 1990-2000: an update.

OBJECTIVES: This report presents detailed pregnancy rates for 1990-2000, updating a national series of rates extending since 1976. METHODS: Tabular data on pregnancy rates by age, race, and Hispanic origin, and by marital status are presented and briefly described. RESULTS: In 2000 an estimated 6,401,000 pregnancies resulted in 4.06 million live births, 1.31 million induced abortions, and 1.03 million fetal losses. The 2000 pregnancy rate of 104.0 pregnancies per 1,000 women aged 15-44 years is 10 percent lower than the 1990 peak of 115.6. The teenage pregnancy rate dropped 27 percent during 1990-2000, reaching an historic low of 84.5 pregnancies per 1,000 women aged 15-19 years. Rates for younger teenagers declined relatively more than for older teenagers.

Abortion, Induced↗

PubMed2003

Births: final data for 2002.

OBJECTIVES: This report presents 2002 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. METHODS: Descriptive tabulations of data reported on the birth certificates of the 4.022 million births that occurred in 2002 are presented. Denominators for population-based rates are derived from the 2000 U.S. census. Rates for 1991-2001 may differ from those published previously based on the 1990 U.S. census. RESULTS: There were 4,021,726 live births in 2002, essentially unchanged from 2001. The birth rate, fertility rate, and total fertility rates all declined 1 percent in 2002. The teenage birth rate dropped 5 percent, reaching another record low. The birth rates for women 20-24 years declined, whereas the rate for women 25-29 years was stable. The birth rate for women 30-34 years declined, but the rate for women 35-44 years continued to rise. Births to unmarried women changed very little. Smoking during pregnancy was down again. The timeliness of prenatal care continued to improve. The cesarean delivery rate climbed to the highest level ever reported in the United States (26.1 percent) and the rate of vaginal birth after previous cesarean plummeted 23 percent to 12.6 percent. Preterm and low birthweight levels both rose for 2002. The twin birth rate continued to climb, but the rate of triplet/+ births was down slightly.

Adolescent↗

PubMed2003

Revised pregnancy rates, 1990-97, and new rates for 1998-99: United States.

OBJECTIVES: This report presents detailed pregnancy rates for 1990-99. Rates for 1991-97 are revised using populations consistent with the April 1, 2000, census; the revised populations are also used for the new 1998-99 rates. METHODS: Tabular and graphic data on pregnancy rates by age, race, and Hispanic origin, and by marital status are presented and described. RESULTS: In 1999, an estimated 6.23 million pregnancies resulted in 3.96 million live births, 1.31 million induced abortions, and 1.0 million fetal losses. The pregnancy rate in 1999 was 102.1 pregnancies per 1,000 women aged 15-44 years. The 1999 rate was similar to the rates since the mid 1990s, but it was 12 percent below the peak rate in 1990 (115.6). These data extend a consistent series of pregnancy rates from 1976 through 1999. The teenage pregnancy rate dropped steadily through the 1990s, reaching a record low of 86.7 per 1,000 aged 15-19 years in 1999, 25 percent lower than the 1990 peak (116.3). Rates fell more for younger than for older teenagers. The declines reflect reductions in births and abortions.

Abortion, Induced↗

PubMed2003

Revised birth and fertility rates for the 1990s and new rates for Hispanic populations, 2000 and 2001: United States.

OBJECTIVES: This report presents revised birth and fertility rates for 1991-99, as well as previously published revised rates for 2000-2001, based on populations consistent with the April 1, 2000, census. Revised rates for Hispanic subgroups (Mexican, Cuban, Puerto Rican, and other Hispanic) are also included in this report. Rates are presented by age, race, and Hispanic origin of mother; by age, race, Hispanic origin, and marital status of mother; by age and race of father; and by age of mother and by State. This report also presents new rates by age and Hispanic origin (subgroups) of mother for 2000 and 2001. The revised rates are compared with previously published rates that used July 1 population estimates based on the 1990 census. METHODS: Populations for most rates were produced for the Centers for Disease Control and Prevention's National Center for Health Statistics (NCHS) under a collaborative arrangement with the U.S. Census Bureau. Populations for teenage subgroups 15-17 and 18-19 years by race and Hispanic subgroups were produced by NCHS. The populations reflect the results of the 2000 census. This census allowed people to report more than one race for themselves and their household members, and also separated the category for Asian or Pacific Islander persons into two groups (Asian and Native Hawaiian or Other Pacific Islander). These changes reflected the Office of Management and Budget's (OMB) 1997 revisions to the standards for the classification of Federal data on race and ethnicity. Because only one race is currently reported in birth certificate data, the 2000 census populations were "bridged" to the single race categories specified in OMB's 1977 guidelines for race and ethnic statistics in Federal reporting, which are still in use in the collection of vital statistics data. RESULTS: Revised population-based birth and fertility rates from 1991 to 1999, based on the 2000 census, are with few exceptions lower than the rates previously published based on populations projected from the 1990 census. As expected, the differences in rates for American Indians, Hispanics, and Asian or Pacific Islanders were considerable. However, revised rates for most other population subgroups (i.e., non-Hispanic whites and blacks) differed little from those previously published. Regardless of the magnitude, the differences between the 2000-based and 1990-based rates progressively diverged through time so that previously published trends were generally retained but lower. Because of this shift, especially for Hispanic women, the differentials in fertility among population subgroups remain, but were somewhat reduced.

Adolescent↗

PubMed2003

Revised birth and fertility rates for the United States, 2000 and 2001.

OBJECTIVES: This report presents revised birth and fertility rates for 2000 and 2001, based on populations consistent with the April 1, 2000, census. Rates are presented by age, race, and Hispanic origin of mother; by age, race, and Hispanic origin of mother for unmarried women; and by age and race of father. To put the rates for 2000 and 2001 into context, rates are also shown for 1990. METHODS: Populations were produced for the Centers for Disease Control and Prevention's National Center for Health Statistics under a collaborative arrangement with the U.S. Census Bureau. The populations reflect the results of the 2000 census. This census allowed people to report more than one race for themselves and their household members, and also separated the category for Asian or Pacific Islander persons into two groups (Asian; Native Hawaiian or Other Pacific Islander). These changes reflected the Office of Management and Budgets 1997 revisions to the standards for the classification of Federal data on race and ethnicity. Because only one race is currently reported in birth certificate data, the 2000 census populations were "bridged" to the single race categories specified in the Office of Management and Budget's 1977 guidelines for race and ethnic statistics in Federal reporting, which are still in use in the collection of vital statistics data. RESULTS: Population-based birth and fertility rates for 2000 and 2001, based on the 2000 census, are somewhat lower for Hispanics (11 percent for the fertility rate in 2001) and Asian or Pacific Islanders (7 percent) and considerably lower for American Indians (18 percent) than the rates previously published based on populations projected from the 1990 census. Rates for most other population subgroups differ little from those previously published. Because of these patterns, the differentials in fertility among population subgroups remain, but are somewhat reduced. Between 1990 and 2001, teenage birth rates declined, rates for women in their twenties changed little, and rates for women in their thirties and forties rose.

Adolescent↗

PubMed2003

Trends and variations in smoking during pregnancy and low birth weight: evidence from the birth certificate, 1990-2000.

OBJECTIVE: This study compares patterns of tobacco use during pregnancy over time and across population subgroups and examines the impact of maternal smoking on the incidence of low birth weight (LBW). The study also evaluates the use of birth certificates to monitor prenatal smoking. METHODS: The birth certificates of all states (except California) and the District of Columbia for 2000 provided to Centers for Disease Control and Prevention's National Center for Health Statistics were analyzed. Trends in maternal smoking were examined with data from birth certificates and other relevant sources. RESULTS: Smoking during pregnancy was reported for 12.2% of women who gave birth in 2000, down 37% from 1989 (19.5%), when this information was first collected on birth certificates. Throughout the 1990s, prenatal smoking rates were highest for older teenagers and women in their early 20s. Among population subgroups, the highest rates were reported for non-Hispanic white women who attended but did not complete high school. The incidence of LBW among singleton infants who were born to smokers was double that for nonsmokers. This relationship was observed in all age groups, for births to Hispanic and non-Hispanic white and black women, and within educational attainment subgroups. Even light smoking (<5 cigarettes daily) was associated with elevated rates of LBW. CONCLUSION: Although prenatal smoking may be underreported on the birth certificate, the trends and variations in smoking based on birth certificate data have been confirmed with data from other sources. Birth certificate data can be useful in monitoring prenatal smoking patterns. Changes in the birth certificate questions that are to be implemented beginning in 2003 will help to clarify the levels and changes in smoking behavior during pregnancy so that smoking cessation programs can be more effectively designed to meet the needs of the populations at risk.

Adolescent↗

PubMed2002

Births: final data for 2001.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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.

Adolescent↗

PubMed2002

Teenage births in the United States: state trends, 1991-2000, an update.

OBJECTIVES: This report provides State-specific birth rates for teenagers for 1991 and 2000, and the percent change between the time periods. METHODS: Tabular and graphical description of trends in teenage birth rates by age group for each State and territory. RESULTS: Birth rates for teenagers 15-19 years declined significantly in all States, the Virgin Islands and Guam, between 1991 and 2000. Declines by State ranged from 12 to 39 percent. Rates also fell significantly for teenage subgroups 15-17 and 18-19 years.

Adolescent↗

PubMed2002

Births: final data for 2000.

OBJECTIVES: This report presents 2000 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. METHODS: Descriptive tabulations of data reported on the birth certificates of the 4.059 million births that occurred in 2000 are presented. RESULTS: The number of births rose 3 percent in 2000; birth and fertility rates rose 1 to 2 percent. The total fertility rate was above "replacement" for the first time in almost 30 years. Teenage birth rates continued to fall while birth rates for women aged 20-24 years rose slightly, and rates for women in their late twenties and thirties rose 3 to 5 percent. Births to women in their forties and early fifties were also up for 2000. The number of births to unmarried women, the birth rate, and the percent of births that were to unmarried women rose 1 to 3 percent, but birth rates for unmarried teenagers declined. Smoking by pregnant women was down again. The cesarean delivery rate rose 4 percent to 22.9, the fourth consecutive increase; the primary cesarean rate was up and the rate of vaginal births after a previous cesarean was down. The number and rate of twin births continued to rise, but the triplet/+ birth rate declined for the second year in a row. For the first year in almost a decade the preterm birth rate declined (to 11.6 percent); the low birthweight rate, however, was unchanged at 7.6 percent.

Adolescent↗