US births increased 3% between 2005 and 2006 to 4265996, the largest number since 1961. The crude birth rate rose 1%, to 14.2 per 1000 population, and the general fertility rate increased 3%, to 68.5 per 1000 women 15 to 44 years. Births and birth rates increased among all race and Hispanic-origin groups. Teen childbearing rose 3% in 2006, to 41.9 per 1000 females aged 15 to 19 years, the first increase after 14 years of steady decline. Birth rates rose 2% to 4% for women aged 20 to 44; rates for the youngest (10–14 years) and oldest (45–49) women were unchanged. Childbearing by unmarried women increased steeply in 2006 and set new historic highs. The cesarean-delivery rate rose by 3% in 2006 to 31.1% of all births; this figure has been up 50% over the last decade. Preterm and low birth weight rates also increased for 2006 to 12.8% and 8.3%, respectively. The 2005 infant mortality rate was 6.89 infant deaths per 1000 live births, not statistically higher than the 2004 level. Non-Hispanic black newborns continued to be more than twice as likely as non-Hispanic white and Hispanic infants to die in the first year of life in 2004. For all gender and race groups combined, expectation of life at birth reached a record high of 77.9 years in 2005. Age-adjusted death rates in the United States continue to decline. The crude death rate for children aged 1 to 19 years decreased significantly between 2000 and 2005. Of the 10 leading causes of death for children in 2005, only the death rate for cerebrovascular disease was up slightly from 2000, whereas accident and chronic lower respiratory disease death rates decreased. A large proportion of childhood deaths, however, continue to occur as a result of preventable injuries.
- teenage fertility
- infant mortality
- low birth weight
- multiple births
- cesarean rate
- vital statistics
- revised certificates
This annual article is a long-standing feature in Pediatrics. The most current vital statistics information available is presented. Birth information is for 2006 (preliminary data) and 2005 (final data). The most current data available for deaths are for 2005 (preliminary) and 2004 (final). We have also included a special feature on new health data from the revised birth certificate.
The data presented in this report were obtained from vital statistics records: birth certificates, fetal death reports, and death certificates for residents of the United States. Birth data for 2006 and death data for 2005 are preliminary and are based on ≥99% of records. Birth data for 2005 and death data for 2004 and earlier years are final and include all records. More complete descriptions of vital-statistics data systems are available elsewhere.1–6
Current vital-statistics patterns and recent trends through 2005 and 2006 are presented according to age, race, and Hispanic origin as well as other birth and death characteristics. More detailed data are available for final 2005 births than for preliminary 2006 births; thus, some of the detailed analyses of birth patterns are presented by using 2005 data. Data on infant deaths from the linked birth/infant death data set are based on final data for 2004. Hispanic origin and race are collected as separate items in vital records. Persons of Hispanic origin may be of any race, although most births and deaths of infants of Hispanic origin are to white women.3 A number of reporting areas allow for the reporting of multiple-race categories (see “Births: Final Data for 2005”3 and “Deaths: Final data for 2004”4). The mother's marital status for birth data, underlying cause of death for deaths, and birth weight for infant deaths have the following special considerations: the mother's marital status was reported directly on the birth certificates or through the electronic birth-registration process in all but 2 states (Michigan and New York) in 2005 and 2006, and details about the reporting of marital status in those 2 states and methods of edits and imputations applied to other items on the birth certificate are presented in National Center for Health Statistics (NCHS) publications.1,3,5
Cause-of-death statistics in this report are based solely on the underlying cause of death compiled in accordance with the International Classification of Diseases, 10th Revision (ICD-10).7 The underlying cause of death is defined as “(a) the disease or injury which initiated the train of morbid events leading directly to death, or (b) the circumstances of the accident or violence which produced the fatal injury.”7 Ranking for leading causes of death is based on number of deaths.8
Infant mortality refers to the death of an infant <1 year old. Infant mortality rates (IMRs) were computed by dividing the total number of infant deaths in each calendar year by the total number of live births in the same year. Neonatal mortality rates (NMRs) are shown for infants who died between 0 and 27 days of age, and postneonatal mortality rates (PNMRs) are shown for infants who died between 28 days and 1 year of age. Perinatal mortality rates (PMRs) include fetal deaths at ≥28 weeks of gestation and infant deaths at <7 days of age. Fetal mortality rates (FMRs) are shown for fetal deaths at ≥20 and at ≥28 weeks of gestation. FMRs and PMRs were computed by dividing the number of fetal or perinatal deaths by the number of live births plus fetal deaths.
The latest infant mortality statistics according to race and Hispanic origin are from the 2004 period linked birth/infant death data set.9 In this data set, the death certificate was linked with the corresponding birth certificate for each infant who died in the United States in 2004. The purpose of this linkage is to use additional variables available from the birth certificate, such as birth weight, to better interpret infant mortality patterns. Numbers of infant deaths were weighted to compensate for the infant deaths for whom the matching birth certificate could not be identified.9 The weighting procedure results in the same overall IMR as that based on unlinked mortality data; however, small differences may exist because of geographic coverage differences, additional quality control, and weighting.9
Data presented for 2006 births are for selected items that were collected on both the 1989 and the 2003 US Standard Certificates of Live Birth. The 2003 revision is described in detail elsewhere.3,5,10,11 Nineteen states, or reporting areas (California, Delaware, Florida, Idaho, Kansas, Kentucky, Nebraska, New Hampshire, New York [excluding New York City], North Dakota, Ohio, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Vermont, Washington, and Wyoming), and Puerto Rico had implemented the revised birth certificate as of January 1, 2006. The nineteen revised states’ data represent 49% of all births in 2006. Information on prenatal care and smoking during pregnancy are not comparable between the 2003 and the 1989 revisions of the US Standard Certificate of Live Birth (revised).10,11 Accordingly, data on these topics are shown separately for the revised and unrevised reporting areas. Information on prenatal care, smoking during pregnancy, and the expanded health data from the new birth certificate are based on the 12 states (Florida, Idaho, Kansas, Kentucky, Nebraska, New Hampshire, New York [excluding New York City], Pennsylvania, South Carolina, Tennessee, Texas, and Washington) that implemented the revised birth certificate as of January 1, 2005. Data for this 12-state reporting area represent 31% of all 2005 births.3
Seventeen states (California, Connecticut, Florida, Idaho, Kansas, Michigan, Montana, Nebraska, New Hampshire, New Jersey, New York [including New York City], Oklahoma, South Carolina, South Dakota, Utah, Washington, and Wyoming) used the 2003 revision of the US Standard Certificate of Death (revised) for all of 2005. The District of Columbia implemented the 2003 revision for part of 2005. The remaining states collected and reported 2005 death data that were based on the 1989 revision of the US Standard Certificate of Death (unrevised).2 All mortality data items presented in this report are considered comparable between revisions; accordingly, revised and unrevised data are combined.
Population denominators for the calculation of birth, death, and fertility rates are estimates that are based on the population enumerated by the US Census Bureau as of April 1, 2000. Estimates for 2000–2005 and the revised estimates for the intercensal period 1991–1999 were produced under a collaborative arrangement between the US Census Bureau and the NCHS. Reflecting the new guidelines issued in 1997 by the Office of Management and Budget (OMB), the 2000 census included an option for individuals to report >1 race as appropriate for themselves and household members12 and for the reporting of Asian persons separately from Native Hawaiians or other Pacific Islanders. Under the previous OMB standards issued in 1977, data for Asian or Pacific Islander persons were collected as a single group.13 Birth and death certificates for most states currently collect only 1 race for mother and decedent in the same categories as specified in the 1977 OMB guidelines and do not report Asian persons separately from Native Hawaiian or other Pacific Islander persons. Because the transition to the 1997 guidelines is not complete, birth and death certificate data according to race (the numerators for birth and death rates) are currently incompatible with the population data collected in the 2000 census (the denominators for the rates).
To produce birth and death rates for 2000–2006 and revised intercensal rates for the 1991–1999 period, it was necessary to “bridge” the reported population data and birth and death data for multiple-race persons back to single-race categories. In addition, the 2000 census counts were modified to be consistent with the 1977 OMB race categories, that is, to report the data for Asians and Native Hawaiians or other Pacific Islanders as a combined category of Asian or Pacific Islanders.14 The procedures used to produce the bridged populations and characteristics of births to multiple-race women have been described in separate publications.14–16
Data for the international comparisons of births, birth rates, and IMRs were obtained from the 2004 United Nations Demographic Yearbook.17
Nearly 1.7 million persons were added to the US population in 2005 as a result of natural increase, or the excess of births over deaths (Table 1).2,3 The rate of natural increase was 5.7 persons per 1000 population in 2005.
The preliminary estimate of infants born in the United States in 2006 was 4265996, an increase of 3% from the 2005 number (Table 1),1 and the largest number of births reported for the United States since 1961. The crude birth rate for 2006 was 14.2 births per 1000 total population, up 1% from 2005; the general fertility rate (the number of births per 1000 women in their childbearing years) rose 3% in 2006 to 68.5, the highest level since 1991. Birth rates increased among all age groups from 15 to 44 years. The total fertility rate also rose for 2006, by 2%, to 2101.0 births per 1000 women. The total fertility rate estimates the number of births that a hypothetical group of 1000 women would have if they experienced, throughout their childbearing years, the age-specific birth rates observed in a given year. Because it is computed from age-specific birth rates, the total fertility rate is age-adjusted, and it is not affected by changes over time in the age composition.
Racial and Ethnic Composition
General fertility rates rose for each race and ethnic group between 2005 and 2006.1 Increases ranged from 1% for Asian or Pacific Islander women to 5% for non-Hispanic black and Native American women. Rates for non-Hispanic white and Hispanic women rose 2%. Fertility rates differ widely among race and ethnic groups (Table 2). Fertility rates based on preliminary 2006 data ranged from a low of 59.5 for non-Hispanic white women to a high of 101. 5 for Hispanic women.1 The number of births to Hispanic women was >1 million for the first time in the United States. Hispanic births comprised 24% of all births in 2006 compared with 15% in 1990.1,3
Trends in Age-Specific Birth Rates
The birth rate for US teenagers rose 3% in 2006, interrupting a 14-year period of steady declines that have been reported since 1991.1 The preliminary rate for 2006 was 41.9 per 1000 women aged 15 to 19, up from the historic low of 40.5 recorded in 2005.1,3,18 The rate had fallen 34% during 1991–2005. The 2005–2006 increases were widespread and affected most teen population subgroups and age groups (Tables 2 and 3, Fig 1). Birth rates rose 2% for Hispanic (to 83.0 per 1000), 3% for non-Hispanic white (26.6), 4% for Native American (54.7), and 5% for non-Hispanic black teens (63.7). The rate for Asian/Pacific Islander teens (16.7) remained essentially unchanged.
Birth rates rose 3% for young women aged 15 to 17 (to 22.0 per 1000) and 4% for those aged 18 to 19 (to 73.0). The only age group that did not experience an increase among teenagers was the youngest teenagers aged 10 to 14 years; the rate for this group declined slightly from 0.7 to 0.6 per 1000. The increases in teen birth rates in 2006 along with continued population growth translated into a 5% increase in the number of births to teenagers aged 15 to 19 to a preliminary total of 435427 in 2006.1
Childbearing for Women ≥20 years old
Births rates increased for each 5-year age group from 20 to 44 years between 2005 and 2006.1 The largest increase, 4%, was among women aged 20 to 24 years (105.9 per 1000 for 2006). The birth rate rose 1% for women aged 25 to 29 years (to 116.8 per 1000); rates for women aged 30 to 34 and 35 to 39 years each increased 2% to 97.7 and 47.3, respectively. The birth rate for women aged 40 to 44 years rose 3% to 9.4, whereas that for women aged 45 to 49 years was unchanged at 0.6. Birth rates for women aged ≥30 years reached levels in 2006 that had not been reported since the mid- to late 1960s1 (see Table 2 for age-specific rates for 2006).
All measures of childbearing by unmarried women rose steeply in 2006 to historic high levels for the nation according to preliminary data.1 The number of births to unmarried women increased to 1641700, 8% higher than that in 2005. The preliminary total for 2006 is 20% higher than that in 2002, when the recent upturn in nonmarital births began. The birth rate for unmarried women rose from 47.5 births per 1000 unmarried women aged 15 to 44 years in 2005 to 50.6 in 2006, a 7% increase. The 2006 birth rate is 16% higher than the recent low point reported for 2002.1,3 The third key measure of nonmarital childbearing is the percentage of births to unmarried women. This measure rose to 38.5% in 2006, compared with 36.9% in 2005 (Table 4). The increases in the number, rate, and percent of births to unmarried women in 2006 were the largest single-year increases reported in these measures since 1988–1989.1,3,19
Smoking During Pregnancy
Information on smoking during pregnancy was reported according to 2 different and noncomparable questions in 2005. For 36 states, New York City, and the District of Columbia, smoking status was based on the 1989 US Standard Certificate of Live Birth (unrevised), whereas data for 11 states are based on the 2003 revision of the US Standard Certificate of Live Birth (revised). California, Florida, and Vermont are excluded. (California did not report tobacco use, the tobacco-use question on the revised Florida birth certificate is not consistent with the US Standard Certificate of Live Birth, and Vermont implemented the revised birth certificate in mid-2005).3 Trend analysis of prenatal smoking is made complicated by the yearly change in the composition of the revised and unrevised reporting areas. Neither the group of revised states nor the group of unrevised states is representative of all states.
Smoking during pregnancy declined slightly to 10.7% of women who gave birth in 2005 compared with 10.9% in 2004 for the same group of 36 unrevised reporting areas3 (these areas accounted for 56% of US births in 2005). Differences among population subgroups were unchanged from previous years. For 2005, the smoking rate was highest for Native American women (at 17.8%), followed by non-Hispanic white women (13.9%) and non-Hispanic black women (8.5%). Rates for Hispanic (2.9%) and Asian or Pacific Islander (2.2%) women were substantially lower.3
For the 11 states for which revised data on tobacco use are available for 2005, the overall smoking rate was 12.4%; the revised reporting area accounted for 25% of US births in 2005. The revised question on smoking differs considerably from the question on the 1989 certificate, and it was expected that the revised question would elicit higher rates of smoking during pregnancy. Variations among population subgroups according to race and Hispanic origin noted above are also apparent for the revised states.3 It is believed that the new question on prenatal smoking is providing higher-quality, more reliable information, in part because there is a specific time reference (each trimester) and women are afforded the chance to report that their smoking behavior has changed.20–22
Smoking during pregnancy has been repeatedly associated with adverse pregnancy outcomes, including low birth weight (LBW), intrauterine growth retardation, miscarriage, and infant mortality, as well as negative consequences for child health and development.23–25 In the 11 states with the revised question, 11.9% of infants born to smokers were of LBW, compared with 7.5% of infants born to nonsmokers.3
The 2003 revision of the birth certificate also introduced substantive changes to information on the timing of prenatal care.10,11 Accordingly, prenatal care data based on the 1989 and 2003 Standard Certificates of Live Birth are not directly comparable and are presented separately. Trend analysis of prenatal care utilization also is compromised by the changing composition of the revised and unrevised reporting areas.
For the second consecutive year, timely initiation of prenatal care did not improve in the United States in 2005. Prenatal care utilization had risen fairly steadily from 1990 to 2003; levels for 2003–2004 remained essentially unchanged.3 For the 37-state unrevised reporting area in 2005, 83.9% of mothers began care within the first 3 months of pregnancy, a small decline from the level for the same reporting area for 2004 (84.2%). For the 12 revised states, 70.2% of mothers were reported to have begun care within the first 3 months of pregnancy. Among the 7-state reporting area for which comparable data are available from revised certificates for 2004–2005, essentially no change was observed in the percentage of women who received first-trimester care.3
The percentages of women with first-trimester care declined among non-Hispanic white mothers in both revised and unrevised reporting areas between 2004 and 2005. Utilization generally improved, however, for non-Hispanic black and Hispanic mothers in both the revised and unrevised reporting areas for 2005. Essentially no change was observed in the receipt of timely prenatal care for Native American or Asian or Pacific Islander mothers. Sizable gains in prenatal care utilization have been observed since the early 1990s among groups that historically have had lower levels of care: non-Hispanic black, Hispanic, and Native American women.3,26 These gains may be linked to the expansion of Medicaid coverage for pregnant women in the late 1980s.27 Large disparities according to race and Hispanic origin in the receipt of health care during pregnancy continue to persist, however. In 2005, non-Hispanic black, Hispanic, and Native American women were more than twice as likely as non-Hispanic white women to receive late (care beginning in the third trimester of pregnancy) or no care.
The total cesarean-delivery rate rose to 31.1% of all births in 2006, a 3% increase over the 2005 rate and another record high (Table 4).1 The percentage of all births by cesarean delivery has climbed 50% over the last decade, from 20.7% in 1996. Total cesarean-delivery rates have also risen by a similar magnitude for women at low risk (ie, women with a singleton term infant in vertex presentation).28 The continued climb in the total cesarean-delivery rate is attributable to the increasing rate of primary cesarean delivery and the steep decline in the rate of vaginal birth after cesarean delivery. Data for 2005 indicate that the primary cesarean-delivery rate continued to rise, whereas the vaginal-birth-after-cesarean-delivery rate continued to decrease.3
Cesarean-delivery rates increased for births at all gestational ages between 1996 and 2005.3 Among singletons only, cesarean-delivery rates rose by 33% to 50% for each gestational-age category, including very preterm infants (<32 completed weeks of gestation) (see Fig 2).
Among the largest racial and Hispanic-origin groups, total cesarean rates in 2006 were highest for non-Hispanic black (33.1) compared with non-Hispanic white (31.3) and Hispanic women (29.7).
The 2005 twin birth rate was 32.2 per 1000, which was unchanged from 2004 (Table 4).3 The twin birth rate (twins per 1000 total births) had been rising steadily, climbing an average of 3% per year between 1990 and 2004, for a total increase of 42% since 1990 and 70% since 1980. The number of live births in twin deliveries rose 1% between 2004 and 2005 to 133122 births; this number has almost doubled since 1980 (from 68 339).
The downward trend in the rate of triplet and higher-order multiple births (triplet/+) observed since 1999 continued in 2005. The 2005 rate was 161.8 per 100000 births, compared with 176.9 in 2004. The triplet/+ birth rate (the number of triplets, quadruplets, and quintuplets and other higher-order multiples per 100000 live births) climbed by >400% during the 1980s and 1990s and peaked at 193.5 per 100000 births in 1998. This rate has been declining slowly since, however, and the 2005 level is 16% lower than the 1998 high.
The dramatic rise in multiple births over the last 2 decades has been of large public health concern because of their high risk of preterm birth, LBW, long-term morbidity, and early death.3,9,29 Twins are 5 times, and triplets nearly 15 times, more likely than singletons to die within 1 month of birth.9 Two related trends have been closely associated with the rise in multiple births: the older age at childbearing (women in their 30s are more likely than younger women to conceive multiples spontaneously) and the widening use of fertility therapies.30,31
The shift toward earlier delivery observed among singletons (noted in the next section) is even more apparent among multiples. Between 1990 and 2005, the percentage of twins delivered preterm has risen from 48% to 60%, with large increases seen both among twins born at <34 weeks of gestation and at 34 to 36 weeks of gestation. A marked trend toward shorter pregnancies was also observed among triplets over this period.3
The preterm birth rate rose slightly in 2006 to 12.8%, from 12.7% in 2005 (Table 4).1 The percentage of births delivered preterm (ie, at <37 completed weeks of gestation) has risen 21% since 1990 (Fig 3). Small increases were observed for 2005–2006 in the percentages of infants delivered at <34 weeks of gestation (3.63%–3.66%) and at 34 to 36 weeks of gestation (9.09%–9.14%). Since 1990, births at <34 weeks of gestation have risen 10%, and late-preterm births (34–36 weeks of gestation) have risen by 25%.3 Although at lower risk of poor outcome than infants who are born at earlier gestational ages, late-preterm births comprise the bulk of all preterm births, and these infants are at heightened risk when compared with infants delivered at term or later.9,32
Between 2005 and 2006, preterm birth rates were essentially unchanged among non-Hispanic white (11.7%) and non-Hispanic black women (18.4%) but increased slightly among Hispanic women (from 12.1% to 12.2%). Since 1990, preterm rates have risen 38% among non-Hispanic white and 11% among Hispanic births. The preterm rate for non-Hispanic black births declined modestly during the 1990s but has risen 6% since 2000. The disparity in infants born at very short gestation according to race has been linked to the substantial black/white gap in infant mortality.33
Although the increase in preterm birth rates in recent years is influenced by the upturn in multiple births, who tend to be born earlier than singletons, rates have also been on the rise among singletons.3 Between 1990 and 2005, the singleton preterm birth rate rose 13% (from 9.7%). All of the increase was among late-preterm births; the proportion of singleton births at <34 weeks of gestation remained essentially unchanged over this period.3
The trend toward earlier deliveries is also seen among term and higher gestations (≥37 weeks). Among singletons, the percentage of births delivered at ≥40 weeks of gestation declined 14% between 2000 and 2005 and 29% between 1990 and 2005. In contrast, the percentage of births delivered at 37 to 39 weeks of gestation increased 10% and 31% over these time periods, respectively.3
Low Birth Weight
The LBW rate also rose slightly for 2005–2006 from 8.2% to 8.3%.1 The percentage of infants born LBW (<2500 g) has risen fairly consistently in recent years; the 2006 level is 19% higher than that for 1990 (7.0%) (Table 4, Fig 3). The elevation in LBW has also been associated with increases in multiple deliveries; however, LBW among singletons has also risen over this period.3 The percentage of infants born very LBW (VLBW; <1500 g) did not change significantly between 2005 and 2006 (1.48% in 2006), but moderately LBW (1500–2499 g) rose from 6.70% to 6.78%. LBW increased among Hispanics, but was essentially unchanged for non-Hispanic white and non-Hispanic black newborns between 2005 and 2006. The lower an infant's birth weight, the greater the risk of early death or long-term disability. In 2004, nearly one fourth of all VLBW infants compared with less than half of 1% of normal weight infants (≥2500 g) did not survive their first year of life.9
In 2005, 28534 infant deaths (preliminary data) were reported in the United States.2 The preliminary 2005 IMR was 6.89 infant deaths per 1000 live births, which is not significantly different from the 2004 rate of 6.78 (Fig 4, Table 1).2,9 After declining fairly steadily for >40 years, the rate increased in 2002 to 6.9534; rates have been essentially stable since then. The NMR (birth through 27 days of age) was 4.55 in 2005 compared with 4.52 in 2004; the PNMR rose significantly from 2.27 to 2.34 for 2004–2005.2
The 2004 linked birth/infant death data set demonstrates pronounced differences in IMRs according to race and Hispanic origin.9 Infants of non-Hispanic black mothers continued to be more than twice as likely as non-Hispanic white and Hispanic mothers to die in the first year of life (13.60 compared with 5.66 and 5.55 per 1000 live births, respectively). The IMRs for these groups declined somewhat between 1995 and 2000 but have not improved since.
Perinatal and Fetal Morality
The 2004 PMR was 6.69, down slightly from 6.74 in 2003. The PMR is defined as late-fetal (≥28 weeks of gestation) and early-neonatal (<7 days of age) deaths per 1000 live births plus fetal deaths.35 Perinatal morality has been declining fairly consistently for more than half a century.36
In 2004, 25655 fetal deaths of ≥20 weeks of gestation were reported in the United States. This number compares with the 18602 neonatal deaths reported for the same year. The 2004 FMR (fetal deaths per 1000 live births plus fetal deaths) was 6.20 per 1000 live births plus fetal deaths, which is not significantly different from the 2003 level of 6.23. No significant changes were observed between 2003 and 2004 in either early- or late-fetal morality. The early FMR (fetal deaths at 20–27 weeks of gestation) for 2004 was 3.13; the late FMR (fetal deaths at ≥28 weeks of gestation) was 3.09. The overall FMR has declined slowly but steadily between 1990 and 2004. All of the decrease has been in late-fetal morality; early-fetal mortality has not declined.35
Table 5 presents information on fetal and infant mortality according to state for 1995–1997 and 2002–2004. Three years of data are combined to produce more statistically stable state-specific rates. Fifteen states and the District of Columbia reported significant declines in FMRs between these 2 time periods; 4 areas (District of Columbia, Maine, New Mexico, and Oklahoma) reported declines of >20%. Infant mortality declined significantly for 10 states and the District of Columbia; for 3 of these areas (District of Columbia, Iowa, and Minnesota), the magnitude of the decline was >20%. A few states reported increases in their IMRs or FMRs, but none were significant.
The lowest FMR for 2002–2004 was observed in New Mexico; the lowest IMR for this period was in Massachusetts. The highest rates for both outcomes and both time periods were observed for Mississippi.
Leading Causes of Infant Death
More than half of all infant deaths based on preliminary 2005 data were attributable to 5 leading causes: congenital malformations (19.5%); disorders relating to short gestation and LBW, not elsewhere classified (16.5%); sudden infant death syndrome (7.4%); newborn affected by maternal complications of pregnancy (maternal complications) (6.3%); and newborn affected by complication of placenta, cord and membranes (4%).2 The sixth leading cause of death, accidents (unintentional injuries), also accounted for ∼4% of all deaths.
The rank order of leading causes of death can vary according to race or Hispanic origin. For example, in 2004, as in earlier years, disorders related to short gestation and LBW (not congenital malformations) was the leading cause of death among non-Hispanic black and Puerto Rican infants.9
Table 6 shows births, birth rates, and IMRs for the United States and 27 other countries with populations of >2500000 and with IMRs less than the rate for the United States in 2003 and 2004. Malaysia and Croatia were added to the table this year. The countries are ordered from lowest to highest IMR in 2004. For the discussion below, in which 2004 data are not available for a given country, IMRs for 2003 are compared. Six countries had an IMR that was half the US rate in 2004 (2003 for Singapore), and the rate was <5.0 infant deaths per 1000 live births for 22 countries. The US rate remained relatively stable between 2002 and 2004, as did the rate for close to half of the other countries. Only Italy and Cuba showed a distinctive decline in the IMR between 2003 and 2004, whereas New Zealand was the only country to report an increase.
There are a number of potential reasons for the unfavorable position of the United States relative to other countries in relation to the IMR. The high percentage of LBW infants,34 the heterogeneity of the US population, and continuing disparities in health among disadvantaged relative to more advantaged groups are part of the reason.37 There also are a number of researchers who have noted differentials in the reporting of live births versus fetal deaths across countries or have suggested that the reporting of vital events in the United States may be more complete than in other developed countries.37–40 Reporting changes in vital events have been hypothesized as one reason for the rise in the United States of the most vulnerable births (those weighing <1500 g at birth), but the evidence for this hypothesis is limited.38
There were 2447903 deaths (preliminary data) in the United States in 2005 (Table 1), 50288 more than the 2397615 deaths reported in 2004. Age-adjusted death rates are better indicators of the risk of mortality over time than crude death rates, because they control for variations in the age composition of the population. The age-adjusted death rate for 2005 was 798.8 deaths per 100000 US standard population.2 This rate was 0.2% lower than the final 2004 age-adjusted death rate of 800.8 and was a record low for the United States.2,4
Expectation of Life
The estimated expectation of life at birth for a given year represents the average number of years that a group of infants would be expected to live if, throughout their lifetime, they were to experience the age-specific death rates that prevailed during the year of their birth. In 2005, the expectation of life at birth reached a record high of 77.9 years, an increase of 0.1 year from the previous year.2,4 Life expectancy increased from the previous year by 0.2 years for black women, 0.1 year for black men, and remained unchanged for white men and white women, all record highs for the 4 groups. In 2005, life expectancy at birth was 80.8 years for white women, 76.5 years for black women, 75.7 years for white men, and 69.6 years for black men.
Causes of Death
The 15 leading causes of death in 2005 (preliminary data) accounted for >80% of all US deaths (Table 7). Between 2000 and 2005, age-adjusted death rates significantly changed for all of the 15 leading causes of death except for septicemia and assault. The age-adjusted death rate decreased for disease of heart by 18.4%, malignant neoplasms by 7.9%, cerebrovascular diseases by 23.5%, chronic lower respiratory diseases by 2.3%, diabetes mellitus by 2.0%, influenza and pneumonia by 14.4%, and chronic liver disease and cirrhosis by 6.3%. The age-adjusted death rate increased for accidents by 9.2%, nephritis, nephrotic syndrome, and nephrosis by 5.9%, Alzheimer disease by 26.5%, intentional self-harm by 1.9%, essential (primary) hypertension and hypertensive renal disease by 23.1%, and Parkinson disease by 12.3%. Alzheimer disease moved from eighth place in 2000 to the seventh place in the leading-cause-of-death list, and Parkinson disease has moved from 15th in 2000 to the 14th leading cause of death in 2005.
Deaths Among Children
A total of 25018 children and adolescents between the ages of 1 and 19 years died in the United States in 2005 (Table 8).2 The death rate for children 1 to 19 years old in 2005 was 32.2 per 100000 population, 5% lower than the rate of 33.9 in 2000.
For all children aged 1 to 19 years, the first and second leading causes of death in 2005 were accidents and assault. Accidents accounted for 42.4% of all deaths, and assault accounted for 10.9%. The death rate increased for cerebrovascular diseases between 2000 and 2005, and cerebrovascular diseases became the eighth leading cause of death in 2005. The death rate decreased significantly for accidents and chronic lower respiratory diseases between 2000 and 2005. Table 8 provides detailed information on the 5 leading causes of death according to rank in 2005 as well as the number of deaths, the percentage of deaths, and the age-specific death rate for each of the leading causes for 2000 and 2005. Although the rates for some causes increased or decreased in specific age groups, the overall patterns of these death rates did not change significantly from 2000 to 2005.
Expanded Health Data From the New Birth Certificate
The revised 2003 US Standard Certificate of Live Birth includes an array of new health items that can be used to describe patterns and trends in maternal and newborn risk and the utilization and impact of health care.10,11 Selected revised items are now available for >1.2 million births, or 31% of all 2005 births.3,41 Data for this 12-state reporting area (Florida, Idaho, Kansas, Kentucky, Nebraska, New Hampshire, New York [excluding New York City], Pennsylvania, South Carolina, Tennessee, Texas, and Washington) may not be generalizable to the nation as a whole3,41 but, when used responsibly, may expand our understanding of perinatal health in the United States. Illustrative findings for 4 of these new items (prepregnancy diabetes [DM] and gestational diabetes [GDM], admission to an NICU, and surfactant-replacement therapy for the newborn) are presented below.
The 1989 revision of the birth certificate did not differentiate between diabetes developed before pregnancy (DM) and diabetes developed during pregnancy (GDM). The new certificate captures information on both, and these new data suggest that the distinction between DM and GDM is useful in assessing newborn risk. Women with DM were nearly 4 times as likely to give birth to an infant who weighed ≥4500 g (at least 9 lb, 15 oz) and were 3.5 times as likely to have an infant admitted to an NICU compared with women who did not have DM or GDM (Fig 5). (Women could not be reported to have both DM and GDM in birth data.) Indeed, 1 of every 5 infants delivered to a mother with DM was admitted to an NICU compared with 6 of every 100 infants of mothers without diabetes. Women who developed diabetes during pregnancy were less likely than their counterparts with diabetes before pregnancy to have a high birth weight or NICU-admitted infant, but their risk was, nonetheless, much higher than for women reported with neither GDM or DM.
Another potentially informative item on the new certificate is surfactant-replacement therapy given to the newborn. This therapy is primarily used for treatment of respiratory distress among preterm infants. These data indicate that non-Hispanic black newborns were more likely than non-Hispanic white and Hispanic infants to receive surfactant (0.5 compared with 0.4 and 0.3, respectively). The higher overall rate of surfactant receipt of black infants seems to be largely a function of their higher rate of preterm delivery, however. (Preterm rates for this revised reporting area were at least 40% higher for non-Hispanic black infants compared with non-Hispanic white and Hispanic infants.) When examined according to gestational age, non-Hispanic white infants were more likely than their non-Hispanic black and Hispanic counterparts to receive surfactant at nearly all gestational ages (differences between non-Hispanic white and Hispanic term births were not statistically significant). Figure 6 shows the rates of surfactant therapy according to race for infants delivered at <34 weeks of gestation.
For more findings on selected new data items for the revised birth certificate see “Expanded Health Data From the New Birth Certificate: 2005”41 and “Expanded Health Data From the New Birth Certificate: 2004”42 The full public-use 2005 file may be downloaded at: www.cdc.gov/nchs/about/major/dvs/Vitalstatsonline.htm#Downloadable.
Natality data are also available using VitalStats, a new data-access and -analysis tool with interactive prebuilt tables and the ability to build tables and create charts and maps using >100 birth variables. VitalStats is available at www.cdc.gov/nchs/VitalStats.htm.
We thank Stephanie J. Ventura, Brady E. Hamilton, Sharon Kirmeyer, and Martha L. Munson for contributions to the manuscript and content review.
- Accepted December 20, 2007.
- Address correspondence to Joyce A. Martin, MPH, National Center for Health Statistics, Centers for Disease Control and Prevention, 3311 Toledo Rd, Room 7415, Hyattsville, MD 20782. E-mail
The authors have indicated they have no financial relationships relevant to this article to disclose.
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