Estimated pregnancy rates by outcome for the United States, 1990-2004

OBJECTIVES: This report presents detailed pregnancy rates for 1990-2004, updating a national series of rates extending since 1976. Data from the National Survey of Family Growth (NSFG) are used to interpret trends in teenage pregnancy and in total pregnancy and fertility rates. METHODS: Tabular and graphical data on pregnancy rates by age, race and Hispanic origin, and by marital status are presented and described. Birth data are from the birth registration system for all births registered in the United States and reported by state health departments to the National Center for Health Statistics; abortion data are from the Guttmacher Institute and the National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention; and fetal loss estimates are from pregnancy history information collected by the NSFG. RESULTS: In 2004 an estimated 6,390,000 pregnancies resulted in 4.11 million live births, 1.22 million induced abortions, and 1.06 million fetal losses. The estimated pregnancy rate for 2004 was 103.0; the rate varied little between 1995 and 2004. The teenage pregnancy rate dropped 38 percent during 1990-2004, reaching an historic low of 72.2 pregnancies per 1,000 women aged 15-19 years. Rates for younger teenagers declined relatively more than for older teenagers.     

Trends in pregnancy rates for the United States, 1976-97: an update.

OBJECTIVES: This report presents detailed pregnancy rates for 1996 and 1997 to update a recently published comprehensive report on pregnancies and pregnancy rates for U.S. women. METHODS: Tabular and graphic data on pregnancy rates by age, race, and Hispanic origin, and by marital status are presented and described. RESULTS: In 1997 an estimated 6.19 million pregnancies resulted in 3.88 million live births, 1.33 million induced abortions, and 0.98 million fetal losses. The 1997 pregnancy rate of 103.7 pregnancies per 1,000 women aged 15-44 years is the lowest recorded since 1976 (102.7), the first year for which a consistent series of national pregnancy rates is available. The 1997 rate was 10 percent lower than the peak rate in 1990 (115.6). The teenage pregnancy rate dropped steadily through 1997, falling to a record low of 94.3 pregnancies per 1,000 teenagers 15-19 years, 19 percent below the 1990 level (116.3). Rates for younger teenagers declined more than for older teenagers.     

Reproduction rates for 1990-2002 and intrinsic rates for 2000-2001: United States.

OBJECTIVE: This report presents revised rates of reproduction for 1990-93, reproduction rates for 1994-2002, and intrinsic rates for 2000-2001. The revised rates for 1991-93 are based on populations consistent with the April 1, 2000, census, as are the rates for 1994-2002. METHODS: Tabular and graphic data on the reproduction and intrinsic rates by race and Hispanic origin of mother are presented and described. RESULTS: Rates of reproduction (total fertility, gross reproduction, and net reproduction rates), the intrinsic rate of natural increase, and the intrinsic birth rate were lower in 2001 (and 2002) than 1990. Among the race and Hispanic subgroups, the reproduction rates were lower for all groups except Cubans and whites (total). The overall intrinsic death rate increased between 1990 and 2001 with the rate declining for whites (total) but increasing for blacks (total).     

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.     

Foodborne botulism in the United States, 1990-2000

Foodborne botulism, a potentially lethal neuroparalytic disease, is caused by ingesting preformed Clostridium botulinum neurotoxin. We reviewed surveillance data and reports from 1990 to 2000. Of 263 cases from 160 foodborne botulism events (episode of one or more related cases) in the United States, 103 (39%) cases and 58 events occurred in Alaska. Patients' median age was 48 years; 154 (59%) were female; the case-fatality rate was 4%. The median number of cases per event was 1 (range 1-17). Toxin type A caused 51% of all cases; toxin type E caused 90% of Alaska cases. A particular food was implicated in 126 (79%) events. In the lower 49 states, a noncommercial food item was implicated in 70 (91%) events, most commonly home-canned vegetables (44%). Two restaurant-associated outbreaks affected 25 persons. All Alaska cases were attributable to traditional Alaska Native foods. Botulism prevention efforts should be focused on those who preserve food at home, Alaska Natives, and restaurant workers.     

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.     

Estimates of pregnancies and pregnancy rates for the United States, 1976-85.

After increasing by 9 per cent in the period 1976-80 in the United States, pregnancy rates declined by 4 per cent between 1980 and 1984 (from 111.9 to 107.3 pregnancies per 1,000 women aged 15-44 years). Between 1984 and 1985, the rate rose by less than 1 per cent to 108.2. More detailed data by age and race, available only through 1983, indicate that the decline in the 1980-83 period was not shared by all age groups. For example, pregnancy rates continued to increase for women in their thirties, and teenage pregnancy remained substantially the same. In 1983, 61 per cent of all pregnancies ended in live birth, 26 per cent in induced abortion, and 13 per cent in fetal loss. Pregnancy rates in that year were two-thirds higher for women of races other than White than for White women, and pregnancies of other-than-White women were more likely to terminate as an induced abortion or fetal loss. However, White teenagers and teenagers of other races were about equally likely to have their pregnancy end in induced abortion or fetal loss.     

Tularemia--United States, 1990-2000

Tularemia is a zoonotic disease caused by the gram-negative coccobacillus Francisella tularensis. Known also as "rabbit fever" and "deer fly fever," tularemia was first described in the United States in 1911 and has been reported from all states except Hawaii. Tularemia was removed from the list of nationally notifiable diseases in 1994, but increased concern about potential use of F. tularensis as a biological weapon led to its reinstatement in 2000. This report summarizes tularemia cases reported to CDC during 1990-2000, which indicate a low level of natural transmission. Understanding the epidemiology of tularemia in the United States enables clinicians and public health practitioners to recognize unusual patterns of disease occurrence that might signal an outbreak or a bioterrorism event.     

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.     

Trichinosis surveillance, United States, 1987-1990.

Since the Public Health Service began recording statistics on trichinosis in 1947, the number of cases reported by state health departments each year has declined. In the late 1940s, health departments reported an average of 400 cases and 10-15 deaths each year; from 1982 through 1986, the number declined to an average of 57 cases per year and a total of three deaths for the period. From 1987 through 1990, 206 cases of trichinosis from 22 states, including 14 multiple-case outbreaks, were reported to CDC. In 1990, two large outbreaks associated with commercial pork accounted for 106 cases. In the 192 instances in which a suspect food item was identified, pork was implicated in 144 (75%) cases, walrus meat in 34 (18%), and bear meat in 14 (7%). Sausage, the most frequently implicated pork product, was associated with 128 of the 139 cases for which a form of ingested pork was specified. Before 1990, the proportion of cases of trichinosis attributable to consumption of commercial pork had declined steadily. This decline was probably due to a combination of factors, including laws prohibiting the feeding of garbage to hogs, the increased use of home freezers, and the practice of thoroughly cooking pork. Although the incidence of trichinosis has decreased substantially since national reporting was initiated in 1947, a dramatic increase in 1990, resulting from two large outbreaks, emphasizes the need for further education and control measures.     

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.     

Trends in characteristics of births by State: United States, 1990, 1995, and 2000-2002.

OBJECTIVE: This report presents U.S. and State-level data on births, birth rates, fertility rates, sex ratio, marital status, and educational attainment by race and Hispanic origin for 1990, 1995, and 2000-2002. METHODS: Data are presented in detailed tables, summary tables, maps, and graphs. RESULTS: In 2002 there were 4,021,726 live births in the United States, 136,486 fewer than in 1990. Despite a slight decline in the number of births nationwide, a few States witnessed significant increases in the number of live births with most of these States located in the western United States. Some of the westward shift in number of births is attributable to a growing population and some to the age and race composition of the individual States. However, real differences in fertility by State persist even when the effects of age structure and race and ethnic composition of the States' population are taken into account. This report also presents data on sex ratios, percentage unmarried, and educational attainment of mothers. Several observations from these data are noteworthy. The proportion of births to unmarried mothers increased nationally and in every State between 1990 and 2002. Nationally the percentage of mothers with fewer than 12 years of education fell, and the percentage with 16 or more years increased for all racial and ethnic groups. However, at the State level, the percentage of women with fewer than 12 years of education increased for nearly a quarter of the States, despite near universal increases in the percentage of women with 16 or more years of education.     

Highlights of trends in pregnancies and pregnancy rates by outcome: estimates for the United States, 1976-96.

OBJECTIVES: This report presents key findings from a comprehensive report on pregnancies and pregnancy rates for U.S. women. The study incorporates birth, abortion, and fetal loss data to compile national estimates of pregnancy rates according to a variety of characteristics including age, race, Hispanic origin, and marital status. Summary data are presented for 1976-96. Data from the National Survey of Family Growth (NSFG) are used to show information on sexual activity and contraceptive practices, as well as women's reports of pregnancy intentions. METHODS: Tabular and graphic data on pregnancy rates by demographic characteristics are presented and interpreted. Birth data are from the birth registration system for all births registered in the United States and reported by State health departments to NCHS; abortion data are from The Alan Guttmacher Institute (AGI) and the National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention (CDC); and fetal loss data are from pregnancy history information collected in the NSFG. RESULTS: In 1996 an estimated 6.24 million pregnancies resulted in 3.89 million live births, 1.37 million induced abortions, and 0.98 million fetal losses. The pregnancy rate in 1996 was 104.7 pregnancies per 1,000 women aged 15-44 years, 9 percent lower than in 1990 (115.6), and the lowest recorded since 1976 (102.7). Since 1990 rates have dropped 8 percent for live births, 16 percent for induced abortions, and 4 percent for fetal losses. The teenage pregnancy rate has declined considerably in the 1990's, falling 15 percent from its 1991 high of 116.5 per 1,000 women aged 15-19 to 98.7 in 1996. Among the factors accounting for this decline are decreased sexual activity, increases in condom use, and the adoption of the injectable and implant contraceptives.     

Chancroid in the United States, 1981-1990: evidence for underreporting of cases.

Chancroid, a bacterial sexually transmitted disease (STD) characterized by genital ulceration, has reemerged in the United States during the last decade. From 1950 to 1980, cases were infrequently reported. After an epidemic in California in 1981, however, the numbers of cases increased, peaking in 1987 at 5,035. Despite a subsequent decline in numbers of reported cases to 4,223 in 1990, new areas continue to report outbreaks. Interpreting chancroid surveillance data is difficult because confirmatory culture media are not commercially available. In addition, states may not require that unconfirmed or even confirmed cases be reported. To determine if chancroid is more widely distributed than surveillance figures indicate, CDC contacted STD clinics in 115 health departments, located in 32 states, the District of Columbia, and Puerto Rico--areas chosen because they had reported five or more cases of chancroid in any single year during 1986-1990--to determine if cases might be occurring but not reported. Only 16 of the 115 clinics had culture media available for Haemophilus ducreyi, and only nine had laboratory facilities complete enough to definitively diagnose chancroid, syphilis, or genital herpes, the most common STDs characterized by genital ulcers. Five or more clinically likely cases occurring in 1990 were identified in 24 states, seven more than surveillance figures indicated. Surveillance can be improved if a) states utilize the definitions for chancroid cases adopted for use in 1990 and b) microbiology laboratories utilize enhanced diagnostic methods.     

Divergent trends in maternal cigarette smoking during pregnancy: United States 1990-99

While examination of causes for trends in smoking have largely focused on how changes have occurred with maternal age and, less commonly, time period, little is known as to how age, period and birth cohort interact on trends in the prevalence of smoking during pregnancy. We performed a population-based, retrospective cohort study based on the vital statistics records comprised of White (n=24,499,629) and Black (n = 5,096,625) women delivering in the United States in 1990-99. Smoking prevalence rates were derived by seven 5-year maternal age groups (15-19 to 45-49 years), two time periods (1990-94 and 1995-99), and eight 5-year maternal birth cohorts (1945-49 to 1980-84) after adjusting for the confounding effects of gravidity, education, marital status, and lack of prenatal care through multivariable logistic regression models. The prevalence of smoking was 17.3% among Whites, and 13.5% among Blacks, with substantial variations by age, time period, and birth cohort. The rate declined with increasing age among Whites during the 1990-94 and 1995-99 periods. Among Blacks, the rates increased steeply with advancing age up to 25-29 years and began to decline thereafter. Smoking rates declined among both Whites and Blacks with increasing birth cohort within each age strata. These rates were highest among multigravid women (gravida > or = 2), and lowest among primigravid women. The rates among Whites declined with increasing maternal age for each gravida. Among Blacks, smoking rates for each gravida increased with advancing age up to 25-29 years, and plateaued among older women. Variation in smoking prevalence by age, time period, and birth cohort provides impetus for designing interventions to reduce smoking. Such studies should not only consider cross-sectional trends, but also the divergent patterns by age and cohort among women of different race/ethnic groups and gravidity.     

Legionellosis --- United States, 2000-2009

Legionnaires disease (LD), a serious, sometimes lethal pneumonia, and Pontiac fever (PF), an influenza-like, self-limited illness, are the two most common forms of legionellosis, which is caused by Legionella bacteria. Legionellosis cases are reported to CDC through the National Notifiable Disease Surveillance System (NNDSS) and a Supplemental Legionnaires Disease Surveillance System (SLDSS) designed to manage surveillance data on travel-related cases and enhance outbreak detection. For this report, cases reported to NNDSS during 2000-2009 from the 50 states and the District of Columbia (DC) were assessed, and crude and age-adjusted incidence rates per 100,000 persons were calculated. U.S. legionellosis cases reported annually increased 217%, from 1,110 in 2000 to 3,522 in 2009, and the crude national incidence rate increased 192%, from 0.39 per 100,000 persons in 2000 to 1.15 in 2009. Because NNDSS is a passive surveillance system dependent on health-care providers and laboratories reporting cases, the actual incidence of legionellosis in the United States likely is higher. Although NNDSS does not record legionellosis cases by type, 99.5% of the legionellosis cases reported to SLDSS during 2005-2009 were classified as LD and 0.5% as PF. Legionellosis surveillance was added to the population-based Active Bacterial Core surveillance (ABCs) system in January 2011 to assess reasons for these increases in numbers of reported cases. The rise in reported cases reinforces the need for health-care providers in all parts of the United States to test and treat adults with severe community-acquired pneumonia for LD, to be vigilant for health-care--associated LD, and to report legionellosis cases to public health authorities.