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.
KEYWORDS
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
Manuel MoroM.D.
Servicio de Neonatología, Hospital Clínico San Carlos, C/ Martín Lagos s/n
28040, Madrid, Spain