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Mortality trends in extremely premature neonates: insights from the CDC WONDER database from 1999 to 2023
Rebecca Hammond1, Martin Phan1, Olivia Foley1
1Department of Medical Education, School of Medicine, Creighton University, Omaha, NE, United States.
Insights
Mortality for extremely premature infants decreased overall from 1999-2023, but disparities persist among racial groups and between urban and rural areas. Outcomes for extremely premature neonates are not evenly distributed across all demographic groups in the U.S.
Area of Science:
- Neonatal Health
- Public Health
- Epidemiology
Background:
- Premature birth, especially extreme prematurity (born <28 weeks gestation), is a leading cause of infant morbidity and mortality.
- Advances in antenatal and neonatal care have improved survival rates for extremely premature infants.
- Understanding mortality trends and disparities is crucial for targeted interventions.
Purpose of the Study:
- To evaluate trends in mortality rates for extremely premature neonates (<1 year old) in the United States from 1999 to 2023.
- To determine if these mortality trends are evenly distributed across various demographic groups, including sex, race, region, and urban/rural locality.
- To assess the impact of the COVID-19 pandemic on extreme prematurity mortality trends.
Main Methods:
- Utilized the CDC WONDER database for national infant mortality data (1999-2023).
- Employed Joinpoint regression analysis to assess Crude Mortality Rate (CMR) trends, including Annual Percent Change (APC) and Average Annual Percent Change (AAPC).
- Stratified data analysis by infant sex, race/ethnicity, geographic region, and urban versus rural location.
Main Results:
- A total of 92,917 deaths were recorded for extremely premature neonates from 1999-2023, with an overall significant decrease in CMR (AAPC -1.14%).
- Significant CMR declines were observed for both males and females, and for Black/African American and White neonates.
- Mortality rates decreased in urban areas but showed no significant decrease in rural areas; the West region showed a non-significant decline.
Conclusions:
- Despite overall improvements, significant disparities in extreme prematurity mortality persist among different demographic groups in the U.S.
- Outcomes for extremely premature infants are not equitably distributed across racial and geographic lines.
- No substantial changes in mortality trends were directly attributable to the COVID-19 pandemic during the study period.
Introduction:
Premature birth is associated with significant morbidity and mortality. Risk increases with younger gestational age. The ICD-10-CM code classifies extremely immature neonates as being born at less than 28 weeks gestation. Antenatal and neonatal interventions have improved outcomes overall. This study evaluates trends in extreme prematurity related mortality to determine if outcomes are evenly distributed among demographic groups, including pre and post COVID data.
Methods:
The CDC WONDER database was utilized to gather data on extreme immaturity related mortality in infants <1 year old from 1999 to 2023. Joinpoint regression was subsequently utilized for data analysis, analyzing crude mortality rate (CMR), annual percent change (APC), and average annual percent change (AAPC), stratifying data by sex, race, region, and urban vs. rural locality.
Results:
Extreme immaturity resulted in 92,917 deaths among neonates in their first year of life from 1999 to 2023. Overall CMR significantly decreased across the study period [AAPC -1.14* 95% CI (-1.45, -0.83)], with both female and male neonates experiencing a significant decrease in CMR [AAPC -1.32* 95% CI [-1.63, -1.06] and AAPC -1.10* 95% CI [-1.57, -0.68] respectively]. Black or African American neonates had a higher CMR than all other racial and ethnic groups. Of all the racial and ethnic groups, CMR significantly decreased only for Black or African American and White neonates [AAPC -1.98* 95% CI [-2.62, -1.46] and AAPC -1.12* 95% CI [-1.42, -0.82] respectively]. All US regions experienced significant declines in CMR except for the West [AAPC -0.72 95% CI (-1.32, 0.19)]. CMR decreased in urban localities but did not decrease in rural localities [AAPC -0.93* 95% CI [-1.24, -0.59] vs. AAPC 0.12 95% CI [-0.51, 0.96]].
Conclusions:
While medical advancements have improved outcomes for neonates born extremely premature, these outcomes are not evenly distributed amongst demographic groups in the United States. There was no large change in trends associated with the COVID-19 pandemic.
