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Published on: November 20, 2015
Causes and timing of death in extremely premature infants from 2000 through 2011
Ravi M Patel1, Sarah Kandefer, Michele C Walsh
1From the Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta (R.M.P., E.C.H., B.J.S.); the Social, Statistical, and Environmental Sciences Unit, RTI International, Research Triangle Park, NC (S.K.); the Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland (M.C.W., N.S.N.), and Department of Pediatrics, Nationwide Children's Hospital-Ohio State University, Columbus (P.J.S.); the Department of Pediatrics, University of Iowa, Iowa City (E.F.B.); the Division of Neonatology, University of Alabama at Birmingham, Birmingham (W.A.C.); the Department of Pediatrics, Women and Infants Hospital, Brown University, Providence, RI (A.R.L.); the Department of Pediatrics, Wayne State University School of Medicine, Detroit (S.S.); the Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine and Lucile Packard Children's Hospital, Palo Alto, CA (K.P.V.M., M.B.B.); and the Social, Statistical, and Environmental Sciences Unit, RTI International, Rockville (A.D.), and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda (R.D.H.) - both in Maryland.
Insights
Overall mortality declined in extremely premature infants from 2000-2011. Deaths from pulmonary causes, immaturity, infection, and CNS injury decreased, but necrotizing enterocolitis deaths increased.
Area of Science:
- Neonatalogy
- Perinatology
- Pediatric Mortality Research
Background:
- Understanding causes and timing of death in extremely premature infants is crucial.
- This knowledge informs research and family counseling.
- Extremely premature infants (22 0/7 to 28 6/7 weeks gestation) face significant mortality risks.
Purpose of the Study:
- To analyze trends in overall and cause-specific in-hospital mortality.
- To compare mortality across different time periods (2000-2011).
- To identify changes in causes of death for extremely premature infants.
Main Methods:
- Analysis of prospectively collected data on 6075 deaths from 22,248 live births.
- Inclusion of infants with gestational ages from 22 0/7 to 28 6/7 weeks.
- Comparison of mortality rates across three periods: 2000-2003, 2004-2007, and 2008-2011, with adjustments for baseline differences.
Main Results:
- Overall mortality per 1000 live births decreased from 275 (2000-2003) to 258 (2008-2011).
- Pulmonary-related deaths (respiratory distress syndrome, bronchopulmonary dysplasia) significantly decreased.
- Deaths attributed to immaturity, infection, and CNS injury declined, while necrotizing enterocolitis-related deaths increased (30 vs. 23 per 1000 live births).
- 40.4% of deaths occurred within 12 hours of birth; 17.3% occurred after 28 days.
Conclusions:
- Overall mortality in extremely premature infants showed a declining trend between 2000 and 2011.
- Significant reductions were observed in deaths due to pulmonary causes, immaturity, infection, and CNS injury.
- An increase in deaths attributed to necrotizing enterocolitis was noted, highlighting an area for continued focus.
Background:
Understanding the causes and timing of death in extremely premature infants may guide research efforts and inform the counseling of families.
Methods:
We analyzed prospectively collected data on 6075 deaths among 22,248 live births, with gestational ages of 22 0/7 to 28 6/7 weeks, among infants born in study hospitals within the National Institute of Child Health and Human Development Neonatal Research Network. We compared overall and cause-specific in-hospital mortality across three periods from 2000 through 2011, with adjustment for baseline differences.
Results:
The number of deaths per 1000 live births was 275 (95% confidence interval [CI], 264 to 285) from 2000 through 2003 and 285 (95% CI, 275 to 295) from 2004 through 2007; the number decreased to 258 (95% CI, 248 to 268) in the 2008-2011 period (P=0.003 for the comparison across three periods). There were fewer pulmonary-related deaths attributed to the respiratory distress syndrome and bronchopulmonary dysplasia in 2008-2011 than in 2000-2003 and 2004-2007 (68 [95% CI, 63 to 74] vs. 83 [95% CI, 77 to 90] and 84 [95% CI, 78 to 90] per 1000 live births, respectively; P=0.002). Similarly, in 2008-2011, as compared with 2000-2003, there were decreases in deaths attributed to immaturity (P=0.05) and deaths complicated by infection (P=0.04) or central nervous system injury (P<0.001); however, there were increases in deaths attributed to necrotizing enterocolitis (30 [95% CI, 27 to 34] vs. 23 [95% CI, 20 to 27], P=0.03). Overall, 40.4% of deaths occurred within 12 hours after birth, and 17.3% occurred after 28 days.
Conclusions:
We found that from 2000 through 2011, overall mortality declined among extremely premature infants. Deaths related to pulmonary causes, immaturity, infection, and central nervous system injury decreased, while necrotizing enterocolitis-related deaths increased. (Funded by the National Institutes of Health.).
