Elsevier

The Journal of Pediatrics

Volume 151, Issue 5, November 2007, Pages 450-456.e1
The Journal of Pediatrics

Original article
Differences in Mortality between Late-Preterm and Term Singleton Infants in the United States, 1995–2002

https://doi.org/10.1016/j.jpeds.2007.05.002Get rights and content

Objective

To assess differences in mortality between late-preterm (34-36 weeks) and term (37-41 weeks) infants.

Study design

We used US period-linked birth/infant death files for 1995 to 2002 to compare overall and cause-specific early-neonatal, late-neonatal, postneonatal, and infant mortality rates between singleton late-preterm infants and term infants.

Results

Significant declines in mortality rates were observed for late-preterm and term infants at all age-at-death categories, except the late-neonatal period. Despite the decline in rates since 1995, infant mortality rates in 2002 were 3 times higher in late-preterm infants than term infants (7.9 versus 2.4 deaths per 1000 live births); early, late, and postneonatal rates were 6, 3, and 2 times higher, respectively. During infancy, late-preterm infants were approximately 4 times more likely than term infants to die of congenital malformations (leading cause), newborn bacterial sepsis, and complications of placenta, cord, and membranes. Early-neonatal cause-specific mortality rates were most disparate, especially deaths caused by atelectasis, maternal complications of pregnancy, and congenital malformations.

Conclusions

Late-preterm infants have higher mortality rates than term infants throughout infancy. Our findings may be used to guide obstetrical and pediatric decision-making.

Section snippets

Methods

We used the US period-linked birth/infant death data for 1995 to 2002 to compare trends and differences in overall mortality rates by age at time of death between singleton late-preterm infants and term infants born to residents of the 50 states and the District of Columbia. We used aggregated 2000 to 2002 data to compare the differences in cause-specific mortality rates by age at time of death and the ranking of the leading causes of death in these groups. The period-linked data file, compiled

Infant Mortality

Between 1995 and 2002, 187,830 singleton infants died before their first birthday; 18,484 (9.8%) were late-preterm infants, and 67,197 (35.8%) were term infants. Overall infant mortality rates for both late-preterm (by 16.8%, P < .01) and term infants (by 20.0%, P < .01) declined significantly from 1995 to 2002 (Table I). Throughout the study period, overall infant mortality rates were approximately 3 times higher in late-preterm infants than term infants.

From 2000 to 2002, there were 68,697

Discussion

In this national study, we observed significant declines in infant mortality rates for both late-preterm infants and term infants in all the age-at-death categories except the late-neonatal period. Even so, in 2002 late-preterm infants were 3 times more likely than term infants to die before their first birthday and 6 times more likely to die in their first week of life; this disparity has remained relatively unchanged since 1995. Clearly, these 2 groups of infants have distinctly different

References (31)

  • G.J. Escobar et al.

    Rehospitalisation after birth hospitalisation: patterns among infants of all gestations

    Arch Dis Child

    (2005)
  • C. Dani et al.

    Risk factors for the development of respiratory distress syndrome and transient tachypnoea in newborn infants

    Eur Respir J

    (1999)
  • F.F. Rubaltelli et al.

    Epidemiology of neonatal acute respiratory disordersA multicenter study on incidence and fatality rates of neonatal acute respiratory disorders according to gestational age, maternal age, pregnancy complications and type of delivery

    Biol Neonate

    (1998)
  • M.L. Wang et al.

    Clinical outcomes of near-term infants

    Pediatrics

    (2004)
  • D.J. Henderson-Smart

    The effect of gestational age on the incidence and duration of recurrent apnoea in newborn babies

    Aust Paediatr J

    (1981)
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    The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the affiliated agencies.

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