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Changes in mortality and morbidities among infants born at less than 25 weeks during the post-surfactant era
  1. S R Hintz1,
  2. W K Poole2,
  3. L L Wright3,
  4. A A Fanaroff4,
  5. D E Kendrick2,
  6. A R Laptook5,
  7. R Goldberg6,
  8. S Duara7,
  9. B J Stoll8,
  10. W Oh9,
  11. for the NICHD Neonatal Research Network
  1. 1Division of Neonatology, Stanford University Medical Center, Palo Alto, CA, USA
  2. 2Research Triangle Institute, Research Triangle Park, NC, USA
  3. 3Department of Pediatrics, National Institute of Child Health and Human Development, Bethesda, MD, USA
  4. 4Case Western Reserve University, Cleveland, OH, USA
  5. 5Department of Pediatrics, University of Texas-Southwestern Medical Center, Dallas, TX, USA
  6. 6Duke University, Durham, NC, USA
  7. 7Department of Pediatrics, University of Miami, Miami, FL, USA
  8. 8Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
  9. 9Department of Pediatrics, Brown University, Providence, RI, USA
  1. Correspondence to:
    Assistant Professor Hintz
    Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University, 750 Welch Road, Suite 315, Palo Alto, CA 94304 USA;


Objectives: To compare mortality and death or major morbidity (DOMM) among infants <25 weeks estimated gestational age (EGA) born during two post-surfactant era time periods.

Study design and patients: Comparative cohort study of very low birthweight (501–1500 g) infants <25 weeks EGA in the NICHD Neonatal Research Network born during two post-surfactant era time periods (group I, 1991–1994, n  =  1408; group II, 1995–1998, n  =  1348). Perinatal and neonatal factors were compared, and group related mortality and DOMM risk were evaluated.

Results: Mortality was higher for group I (63.1% v 56.7%; p  =  0.0006). Antenatal steroids (ANS) and antenatal antibiotics (AABX), surfactant (p<0.0001), and bronchopulmonary dysplasia (p  =  0.0008) were more prevalent in group II. In a regression model that controlled for basic and delivery factors only, mortality risk was greater for group I than for group II (odds ratio (OR) 1.4, 95% confidence interval (CI) 1.2 to 1.7); the addition of AABX and surfactant, or ANS (OR 0.97, 95% CI 0.79 to 1.2) to the model appeared to account for this difference. There was no difference in DOMM (86.8% v 88.4%; p  =  0.2), but risk was lower for group I in regression models that included ANS (OR 0.70, 95% CI 0.52 to 0.94).

Conclusion: Survival to discharge was more likely during the more recent period because of group differences in ANS, AABX, and surfactant. However, this treatment shift may reflect an overall more aggressive management approach. More consistent application of treatment has led to improving survival of <25 week EGA infants during the post-surfactant era, but possibly at the cost of greater risk of major in-hospital morbidities.

  • AABX, antenatal antibiotics
  • ANS, antenatal steroids
  • BPD, bronchopulmonary dysplasia
  • DOMM, death or major morbidity
  • EGA, estimated gestational age
  • extremely premature
  • mortality
  • outcome
  • surfactant
  • very low birth weight

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  • This study was supported by National Institutes of Health grant and GCRC numbers: U10 HD21364, U10 HD21373, U10 HD21385, U10 HD21415, U10 HD21397, U10 HD27851, U10 HD27881; M01 RR 00997, U10 HD27853; M01 RR 08084, U10 HD27856; M01 RR 00750, U10 HD27871; M01 RR 06022, U10 HD27904, U10 HD27880; M01 RR 00070, U10 HD34216, U10 HD34167; M01 RR02635; M01 RR 02172, M01 RR 02032, U01 HD36790, U01 HD19897

  • Competing interests: none declared