Abstract
Objective This study was aimed to examine differences in infant mortality outcomes across maternal
age subgroups less than 20 years in the United States with a specific focus on racial
and ethnic disparities.
Study Design Using National Center for Health Statistics cohort-linked live birth–infant death
files (2009-2013) in this cross-sectional study, we calculated descriptive statistics
by age (<15, 15–17, and 18–19 years) and racial/ethnic subgroups (non-Hispanic white
[NHW], non-Hispanic black [NHB], and Hispanic) for infant, neonatal, and postneonatal
mortality. Adjusted odds ratios (aOR) were calculated by race/ethnicity and age. Preterm
birth and other maternal characteristics were included as covariates.
Results Disparities were greatest for mothers <15 and NHB mothers. The risk of infant mortality
among mothers <15 years compared to 18 to 19 years was higher regardless of race/ethnicity
(NHW: aOR = 1.40, 95% confidence interval [CI]: 1.06–1.85; NHB: aOR = 1.28, 95% CI:
1.04–1.56; Hispanic: aOR = 1.36, 95%CI: 1.07–1.74). Compared to NHW mothers, NHB mothers
had a consistently higher risk of infant mortality (15–17 years: aOR = 1.12, 95% CI:
1.03–1.21; 18–19 years: aOR = 1.21, 95% CI: 1.15–1.27), while Hispanic mothers had
a consistently lower risk (15–17 years: aOR = 0.72, 95% CI: 0.66–0.78; 18–19 years:
aOR = 0.74, 95% CI: 0.70–0.78). Adjusting for preterm birth had a greater influence
than maternal characteristics on observed group differences in mortality. For neonatal
and postneonatal mortality, patterns of disparities based on age and race/ethnicity
differed from those of overall infant mortality.
Conclusion Although infants born to younger mothers were at increased risk of mortality, variations
by race/ethnicity and timing of death existed. When adjusted for preterm birth, differences
in risk across age subgroups declined and, for some racial/ethnic groups, disappeared.
Key Points
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Infant mortality risk was highest for adolescents <15 years old across racial/ethnic
groups.
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Racial/ethnic disparities in timing of death were present even among the youngest
adolescents.
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Infants of NHB adolescents had greatest risk of mortality, especially as age increased.
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Preterm birth influenced infant mortality risk, especially among NHB adolescents.
Keywords
infant mortality - pregnancy in adolescence - racial disparities - birth outcomes
