Live births of infants less than 23 weeks gestation disproportionately affect infant mortality rates in the United States

Objective Lack of standardization of infant mortality rate (IMR) calculation between regions in the United States makes comparisons potentially biased. This study aimed to quantify differences in the contribution of early previable live births (<20 weeks) to U.S. regional IMR. Study Design Population-based cohort study of all U.S. live births and infant deaths recorded between 2007 and 2014 using Centers for Disease Control and Prevention's (CDC's) WONDER database linked birth/infant death records (births from 17–47 weeks). Proportion of infant deaths attributable to births <20 vs. 20 to 47 weeks, and difference (ΔIMR) between reported and modified (births ≥20 weeks) IMRs were compared across four U.S. census regions (North, South, Midwest, and West). Results Percentages of infant deaths attributable to birth <20 weeks were 6.3, 6.3, 5.3, and 4.1% of total deaths for Northeast, Midwest, South, and West, respectively, p < 0.001. Contribution of < 20-week deaths to each region's IMR was 0.34, 0.42, 0.37, and 0.2 per 1,000 live births. Modified IMR yielded less regional variation with IMRs of 5.1, 6.2, 6.6, and 4.9 per 1,000 live births. Conclusion Live births at <20 weeks contribute significantly to IMR as all result in infant death. Standardization of gestational age cut-off results in more consistent IMRs among U.S. regions and would result in U.S. IMR rates exceeding the healthy people 2020 goal of 6.0 per 1,000 live births.

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State-level trends in sudden unexpected infant death and immunization in the United States: an ecological study

BMC Pediatrics ◽

10.1186/s12887-021-02733-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jacqueline Müller-Nordhorn ◽

Konrad Neumann ◽

Thomas Keil ◽

Stefan N. Willich ◽

Sylvia Binting

Keyword(s):

United States ◽

Infant Mortality ◽

Infant Death ◽

Immunization Coverage ◽

The United States ◽

Mortality Rates ◽

Sleep Position ◽

Live Births ◽

Unexpected Infant Death ◽

Rate Ratios

Abstract Background Sudden unexpected infant death (SUID) continues to be a major contributor to infant mortality in the United States. The objective was to analyze time trends in SUID and their association with immunization coverage. Methods The number of deaths and live births per year and per state (1992–2015) was obtained from the Centers for Disease Control and Prevention (CDC). We calculated infant mortality rates (i.e., deaths below one year of age) per 1000 live births for SUID. We obtained data on immunization in children aged 19–35 months with three doses or more of diphtheria-tetanus-pertussis (3+ DTP), polio (3+ Polio), and Haemophilus influenzae type b (3+ Hib) as well as four doses or more of DTP (4+ DTP) from the National Immunization Survey, and data on infant sleep position from the Pregnancy Risk Assessment Monitoring System (PRAMS) Study. Data on poverty and race were derived from the Current Population and American Community Surveys of the U.S. Census Bureau. We calculated mean SUID mortality rates with 95% confidence interval (CI) as well as the annual percentage change using breakpoint analysis. We used Poisson regression with random effects to examine the dependence of SUID rates on immunization coverage, adjusting for sleep position and poverty (1996–2015). In a second model, we additionally adjusted for race (2000–2015). Results Overall, SUID mortality decreased in the United States. The mean annual percent change was − 9.6 (95% CI = − 10.5, − 8.6) between 1992 and 1996, and − 0.3 (95% CI = − 0.4, − 0.1) from 1996 onwards. The adjusted rate ratios for SUID mortality were 0.91 (95% CI = 0.80, 1.03) per 10% increase for 3+ DTP, 0.88 (95% CI = 0.83, 0.95) for 4+ DTP, 1.00 (95% CI = 0.90, 1.10) for 3+ polio, and 0.95 (95% CI = 0.89, 1.02) for 3+ Hib. After additionally adjusting for race, the rate ratios were 0.76 (95% CI = 0.67, 0.85) for 3+ DTP, 0.83 (95% CI = 0.78, 0.89) for 4+ DTP, 0.81 (95% CI = 0.73, 0.90) for 3+ polio, and 0.94 (95% CI = 0.88, 1.00) for 3+ Hib. Conclusions SUID mortality is decreasing, and inversely related to immunization coverage. However, since 1996, the decline has slowed down.

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Extremely Low Birth Weight and Infant Mortality Rates in the United States

PEDIATRICS ◽

10.1542/peds.2012-2471d ◽

2013 ◽

Vol 131 (5) ◽

pp. X3-X3

Keyword(s):

United States ◽

Birth Weight ◽

Infant Mortality ◽

Low Birth Weight ◽

The United States ◽

Mortality Rates ◽

Extremely Low Birth Weight

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The evolution of infant mortality inequality in the United States, 1960–2016

Science Advances ◽

10.1126/sciadv.aba5908 ◽

2020 ◽

Vol 6 (29) ◽

pp. eaba5908

Author(s):

Nick Turner ◽

Kaveh Danesh ◽

Kelsey Moran

Keyword(s):

United States ◽

Infant Mortality ◽

The United States ◽

Mortality Rates ◽

County Level ◽

Level Data ◽

Antipoverty Programs ◽

The Relationship ◽

Over Time ◽

Mortality Inequality

What is the relationship between infant mortality and poverty in the United States and how has it changed over time? We address this question by analyzing county-level data between 1960 and 2016. Our estimates suggest that level differences in mortality rates between the poorest and least poor counties decreased meaningfully between 1960 and 2000. Nearly three-quarters of the decrease occurred between 1960 and 1980, coincident with the introduction of antipoverty programs and improvements in medical care for infants. We estimate that declining inequality accounts for 18% of the national reduction in infant mortality between 1960 and 2000. However, we also find that level differences between the poorest and least poor counties remained constant between 2000 and 2016, suggesting an important role for policies that improve the health of infants in poor areas.

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Comparison of Neonatal and Infant Mortality Rates between Infants Born in South Korea and Those Born in the United States

Neonatal Medicine ◽

10.5385/nm.2014.21.4.211 ◽

2014 ◽

Vol 21 (4) ◽

pp. 211 ◽

Cited By ~ 2

Author(s):

Ji Sun Lee ◽

Jung Min Yoon ◽

Eun Jung Cheon ◽

Kyong Og Ko ◽

Jae Won Shim ◽

...

Keyword(s):

United States ◽

Infant Mortality ◽

South Korea ◽

The United States ◽

Mortality Rates

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Letters to the Editor

PEDIATRICS ◽

10.1542/peds.41.4.854a ◽

1968 ◽

Vol 41 (4) ◽

pp. 854-855

Author(s):

Myron E. Wegman

Keyword(s):

United States ◽

Infant Mortality ◽

International Comparison ◽

Live Birth ◽

Quantitative Data ◽

The United States ◽

The Other ◽

Letters To The Editor ◽

Live Births ◽

Definition Of

Dr. Thomas is, of course, quite correct in noting that various reporting countries use different definitions of live births, a problem which does complicate the matter of precise comparisons. On the other hand, the report from which Dr. Thomas quotes, International Comparison of Perinatal and Infant Mortality, goes on to analyze several instances in which quantitative data on definitions are available. The major problem, of course, has to do with definition of a live birth; for example, the Swedish definition of a live birth was not the same as that in the United States until 1959.

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Letter To The Editor

PEDIATRICS ◽

10.1542/peds.45.6.1044 ◽

1970 ◽

Vol 45 (6) ◽

pp. 1044-1044

Author(s):

Alfred Yankauer

Keyword(s):

United States ◽

Infant Mortality ◽

Infant Death ◽

The United States ◽

Mortality Rates ◽

European Countries ◽

Death Rates ◽

Letter To The Editor

Second, Dr. Yankauer: "Disgraceful and totally unacceptable" are inflammatory adjectives. They stir up uncomfortable feelings of personal guilt and blame. It would be reassuring if the differences between infant mortality rates in the United States and those of several small European countries with relatively homogenous populations and stable traditions could be explained away as statistical artefacts. Unfortunately the differences cannot be explained away. Clear evidence for their substance is the fact that infant death rates after the first month of life are three times as high in the United States as in Sweden.

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ANNUAL SUMMARY OF VITAL STATISTICS—1967

PEDIATRICS ◽

10.1542/peds.42.6.1005 ◽

1968 ◽

Vol 42 (6) ◽

pp. 1005-1008

Author(s):

Myron E. Wegman

Keyword(s):

United States ◽

Infant Mortality ◽

The United States ◽

Vital Statistics ◽

Downward Trend ◽

Vital Rates ◽

Population Groups ◽

Infant Deaths ◽

Live Births ◽

Second Year

0nmany occasions previously this annual article has included serious criticism of the record of the United States as to infant mortality. It is satisfying, therefore, to report that 1967 marked a second year of a downward trend and that early tentative reports for 1968 are encouraging that the trend has continued. Nevertheless, as will be seen later, there is still a long way to go, and there are too many unacceptably high rates in particular population groups. Each year at this time a report is presented of the national situation in respect of the most significant vital rates, that is live births and infant deaths.

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Infectious Disease-Related Deaths of Low Birth Weight Infants, United States, 1968 to 1982

PEDIATRICS ◽

10.1542/peds.84.2.296 ◽

1989 ◽

Vol 84 (2) ◽

pp. 296-303

Author(s):

Janine M. Jason

Keyword(s):

Infectious Disease ◽

United States ◽

Birth Weight ◽

Infant Mortality ◽

Low Birth Weight ◽

Infectious Diseases ◽

The United States ◽

Mortality Rates ◽

Mortality Data ◽

Tract Infections

Infant mortality rates in the United States are higher than in any other developed country. Low birth weight (LBW) is the primary determinant of infant mortality. Despite city, state, and federal programs to prevent LBW, decreases in infant mortality in the 1980s appear to be largely secondary to improved survival of LBW infants rather than to a decline in the rate of LBW births. Because prevention of mortality due to infectious disease is feasible, it was of interest to examine the role of infectious diseases in LBW infant mortality. US vital statistics mortality data for 1968 through 1982 were analyzed in terms of LBW infant mortality associated with infectious and noninfectious diseases. These analyses indicated that the rates of infectious disease-associated early neonatal and postneonatal LBW mortality increased during this time; late neonatal rates did not decline appreciably. Infectious diseases were associated with 4% of all LBW infant deaths in 1968; this had increased to 10% by 1982. Although LBW infant mortality rates associated with noninfectious diseases did not differ for white and black populations, infectious disease-associated mortality rates were consistently higher for blacks than whites in both metropolitan and nonmetropolitan areas. Chorioamnionitis was involved in 28% of infectious disease-associated early neonatal LBW deaths. Sepsis was an increasingly listed cause of death in all infant age periods, whereas respiratory tract infections were decreasingly listed. Necrotizing enterocolitis increased as a cause of late neonatal mortality. These data suggest that infectious diseases are an increasing cause of LBW infant mortality and these deaths occur more frequently in the black population targeted by prevention programs. More research concerning specific causes and prevention of infections in the LBW infant may help reduce US infant mortality.

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