Mortality for Newborns of Birthweight less Than 1500 g in Spanish Neonatal Units (2002-2005)

ABSTRACT

The purpose of this study was to analyze the mortality and its prognostic factors in a Spanish cohort of very low birthweight (VLBW) infants during the period 2002 to 2005. Using the Spanish Society of Neonatology database (SEN 1500), 8942 infants with a birthweight < 1500 g were recruited. The overall mortality was 17.3%. However, this incidence underwent a significant decrease over the study period, from 19.4% in 2002 to 15.2% in 2005 (p = 0.003). Mortality ranged from 12.4% in 25% of the participating neonatal units to 19.4% in a further 25%. Mortality was higher in outborn infants (25.8%) than in inborn infants (16.6%) (p < 0.001). The mortality rates of these neonates are also presented by 100-g intervals (401 to 1500) and for the different hospitalization times: in the delivery room, within 24 hours and 28 days of birth, at 36 weeks of postmenstrual age, and on discharge. Of note was that mortality was greatest within 24 hours and 28 days of birth in each of the weight groups (p < 0.001). In conclusion, in the cohort of infants < 1500 g examined, mortality in the period from 2002 to 2005 was still high, especially among newborns weighing < 1000 g. We did, however, observe a decreasing trend in mortality rates for the participating neonatal units over the 4 study years. Our findings highlight the need to promote intrauterine transport and improve neonatal transport as well as the management of these infants in the delivery room and within the first 28 days of life.

Very low birthweight - mortality - trend - network

REFERENCES

• 1 Horbar J D, Badger G J, Carpenter J H et al.. for the members of the Vermont Oxford Network. Trends in mortality and morbidity for very low birth weight (VLBW) infants: The Vermont Oxford Network Experience, 1991-1999.  Pediatr Res. 2001;  49 303A
• 2 Horbar J D, Carpenter J, Kenny M et al.. Vermont Oxford Network 2004 Database Summary. Burlington, Vermont; 2005
• 3 Horbar J D, Carpenter J, Kenny M et al.. Vermont Oxford Network 2005 Database Summary. Burlington, Vermont; 2006
• 4 Lee S K, McMillan D D, Ohlsson A et al.. Variations in practice and outcomes in the Canadian NICU Network: 1996-1997.  Pediatrics. 2000;  106 1070-1079
• 5 Lemons J A, Bauer C R, Oh W et al.. Very low birth weight outcomes of the National Institute of Child Health and Human Development Neonatal Research Network, January 1995 through December 1996.  Pediatrics. 2001;  107(1) E1
• 6 Chan K, Ohlsson A, Synnes A et al.. Survival, morbidity, and resource use of infants of 25 weeks' gestational age or less.  Am J Obstet Gynecol. 2001;  185 220-226
• 7 Stollman A L. for the Members of the Vermont Oxford Network. Trends in mortality and morbidity for very low birth weight infants, 1991-1999.  Pediatrics. 2002;  110 143-151
• 8 Hintz S R, Poole W K, Wright L L et al.. Changes in mortality and morbidities among infants born at less than 25 weeks during the post-surfactant era.  Arch Dis Childh Fetal Neonatal Ed. 2005;  90 128-133
• 9 Tin W. Oxygen therapy: 50 years of uncertainty.  Pediatrics. 2002;  110 615-616
• 10 Vento M, Asensi M, Sastr J et al.. Oxidative stress in asphyxiated term infants resuscitated with 100% oxygen.  J Pediatr. 2003;  142 240-246
• 11 Horbar J D, Carpenter J, Soll R F et al.. Factors associated with the timing of the first dose of surfactant for infants 23 to 29 weeks gestation.  Pediatr Res. 2002;  51 348A
• 12 Horbar J D, Carpenter J, Soll R F et al.. Trend to earlier initiation of surfactant therapy from 1998 to 2000.  Pediatr Res. 2002;  51 407A
• 13 Soll R F, Conner J M, Howard D. for the Early Surfactant Replacement Study Group. Early surfactant replacement therapy in spontaneously breathing premature infants with RDS.  Pediatr Res. 2003;  53 397A
• 14 Jackson J K, Vellucci J, Johnson P, Kilbride H W. Evidence-based approach to change in clinical practice: introduction of expanded nasal continuous positive airway pressure use in an intensive care nursery.  Pediatrics. 2003;  111 e542-e547
• 15 Wilson A, Gardner M N, Armstrong M A et al.. Neonatal assisted ventilation: predictors, frequency, and duration in a mature manager care organization.  Pediatrics. 2000;  105 822-830
• 16 Kuzma-O'Reilly B, Duenas M, Greecher C et al.. Evaluation, development and implementations of potentially better practices in neonatal intensive care nutrition.  Pediatrics. 2003;  111 e461-e470
• 17 Mercier C M, Conner J M, Soll R F. for The Extremely Low Birth Weight Infant Follow-Up Group. Survival and outcomes of infants with birth weight less than 1001 grams.  Pediatr Res. 2002;  51 292A
• 18 Mercier C M, Conner J M, Howard D, Cohen H, Magoon M. and Soll RF for the ELBW Follow-up Centers. Expanded follow-up of health and developmental outcome of infants with birthweight (bw) less than 1001 grams.  Pediatr Res. 2003;  53 494A
• 19 Valls i Soler A, Paramo Andrés S, Centerno Monterubio C et al.. Morbimortalidad en recién nacidos de muy bajo peso en el control de la calidad de la asistencia perinatal.  An Pediatr (Barc). 2003;  58 464-470
• 20 Movimiento anual de la población. Anuario Estadístico de España 2002. Demografía. Instituto Español de Estadística.  Madrid. 2003; 
• 21 Movimiento anual de la población. Anuario Estadístico de España 2003. Demografía. Instituto Español de Estadística.  Madrid. 2004; 
• 22 Movimiento anual de la población. Anuario Estadístico de España 2004. Demografía. Instituto Español de Estadística.  Madrid. 2005; 
• 23 Movimiento anual de la población. Anuario Estadístico de España 2005. Demografía. Instituto Español de Estadística.  Madrid. 2006; 
• 24 Darlow B A, Cust A E, Donoghue D A. Improved outcomes for very low birthweight infants: evidence from New Zealand national population based data.  Arch Dis Childh Fetal Neonatal Ed. 2003;  88 F23-F28
• 25 Tommiska V, Heinonen K, Ikonen S et al.. A national short-term follow-up study of extremely low birth weight infants born in Finland in 1996-1997.  Pediatrics. 2001;  107 e2
• 26 Lucey J F, Rowan C A, Shiono P et al.. Fetal infants: The fate of 4172 infants with birth weights of 401 to 500 grams. The Vermont Oxford Network experience (1996-2000).  Pediatrics. 2004;  113 1559-1566
• 27 Markestad T, Kaaresen P I, Ronnestad A et al.. Early Death, Morbidity, and Need of Treatment Among Extremely Premature Infants.  Pediatrics. 2005;  115 1289-1298
• 28 Pollack M M, Koch M A, Bartel D A et al.. A comparison of neonatal mortality risk prediction models in very low birth weight infants.  Pediatrics. 2000;  105 1051-1057
• 29 Costeloe K, Hennessy E, Gibson A T, Marlow N, Wilkinson A R. for The Epicure Study Group. The EPICure study: Outcomes to discharge from hospital for infants born at the threshold of viability.  Pediatrics. 2000;  106 659-671
• 30 Suresh G K, Horbar J D, Kenny M, Carpenter J H. Vermont Oxford Network . Major birth defects in very birth weight infants in the Vermont Oxford Network.  J Pediatr. 2001;  139 366-373
• 31 Liu S. for The Fetal And Infant Health Study Group of The Canadian Perinatal Surveillance System . Relationship of prenatal diagnosis and pregnancy termination to overall infant mortality in Canada.  JAMA. 2002;  287 1561-1567
• 32 Elsmen E, Hansen P, Hellstrom-Westas L. Preterm male infants need more initial respiratory and circulatory support than female infants.  Acta Paediatr. 2004;  93 529-533
• 33 Bhaumik U, Aitken I, Kawachi I, Ringer S, Orav J, Lieberman E. Narrowing of sex differences in infant mortality in Massachusetts.  J Perinatol. 2004;  24 94-99
• 34 Morse S B, Wu S S, Ma C, Ariet M, Resnick M, Roth J. Racial and gender differences in the viability of extremely low birth weight infants: a population-based study.  Pediatrics. 2006;  117(1) e106-e112
• 35 Regev R H, Lusky A, Dolfin T, Litmanovitz I, Arnon S, Reichman B. Excess mortality and morbidity among small-for-gestational-age premature infants: A population-based study.  J Pediatr. 2003;  143 186-191
• 36 Aucott S W, Donohue P K, Northington F J. Increased morbidity in severe early intrauterine growth restriction.  J Perinatol. 2004;  24 435-440
• 37 Bartels D B, Kreienbrock L, Dammann O, Wenzlaff P, Poets C F. Population based study on the outcome of small for gestational age newborns.  Arch Dis Childh Fetal Neonatal Ed. 2005;  90 F53-F59
• 38 Walsh M C, Morris B H, Wrage L A et al.. Extremely low birthweight neonates with protracted ventilation: mortality and 18-month neurodevelopmental outcomes.  J Pediatr. 2005;  146 798-804
• 39 Kantak A D, Lewallen P, Lewis W et al. for the NIC/Q. Project investigators of the Vermont Oxford Network Collaborative Quality Improvement for Neonatal Intensive Care.  Pediatrics. 2001;  107 14-22
• 40 Horbar J D, Plsek P E, Leahy K. NIC/Q 2000: Establishing habits for improvement in neonatal intensive care units.  Pediatrics. 2003;  111 e397
• 41 Wilson-Costello D, Friedman H, Minich N, Fanaroff A A, Hack M. Improved survival rates with increased neurodevelopmental disability for extremely low birth weight infants in the 1990s.  Pediatrics. 2005;  115(4) 997-1003
• 42 Hosono S, Ohno T, Kimoto H, Shimuzu M, Harada K. Morbidity and mortality of infants born at the threshold of viability: ten years' experience in a single neonatal intensive care unit, 1991-2000.  Pediatr Int. 2006;  48(1) 33-39
• 43 Ohlinger J, Brown M S, Laudert S, Swanson S, Fofah O. on behalf of the CARE Group . Development of potentially better practices for the neonatal intensive care unit as a culture of collaboration: communication, accountability, respect, and empowerment.  Pediatrics. 2003;  111 e471
• 44 Horbar J D, Plsek P E, Leahy K, Schriefer J. Introduction to evidence-based quality improvement in neonatal and perinatal medicine: The NIC/Q 2000 experience.  Pediatrics. 2003;  111 e395
• 45 Kilbride H W, Powers R, Wirtschafter D D et al.. Evaluation and development of potentially better practices to prevent neonatal nosocomial bacteremia.  Pediatrics. 2003;  111 e504
• 46 Kilbride H W, Wirtschafter D D, Powers R J, Sheehan M B. Implementation of evidence-based potentially better practices to decrease nosocomial infections.  Pediatrics. 2003;  111 e519
• 47 Kaempf J W, Campbell B, Sklar R S et al.. Implementing potentially better practices to improve neonatal outcomes after reducing postnatal dexamethasone use in infants born between 501 and 1250 grams.  Pediatrics. 2003;  111 e534
• 48 Sharek P J, Baker R, Litman F et al.. Evaluation and development of potentially better practices to prevent chronic lung disease and reduce lung injury in neonates.  Pediatrics. 2003;  111 e426
• 49 McLendon D, Check J, Carteaux P et al.. Implementation of potentially better practices for the prevention of brain hemorrhage and ischemic brain injury in very low birth weight infants.  Pediatrics. 2003;  111 e497
• 50 Moore K A, Coker K, Edwards W H. Implementing potentially better practices for improving family-centered care in neonatal intensive care units: successes and challenges.  Pediatrics. 2003;  111 e450
• 51 Saunders R P, Abraham M R, Crosby M J, Thomas K, Edwards W H. Evaluation and development of potentially better practices for improving family-centered care in neonatal intensive Care Units.  Pediatrics. 2003;  111 e437
• 52 Rogowski J A, Staiger D, Horbar J D, Kenney M, Carpenter J, Geppert J. Quality-based selective referral for neonatal intensive care units. Paper presented at: International Health Economics Association June 2003 San Francisco, CA;
• 53 Rogowski J A, Horbar J D, Plsek P E et al.. Economic implications of neonatal intensive care unit collaborative quality improvement.  Pediatrics. 2001;  107 23-29
• 54 Rogowski J. Using Economic information in a quality improvement collaborative.  Pediatrics. 2003;  111 e411
• 55 Rogowski J A, Horbar J D, Staiger D O, Kenny M, Carpenter J, Geppert J. Indirect versus direct hospital quality indicators for very low birth weight infants.  JAMA. 2004;  291 202-209