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Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
No improvement in outcome of nationwide extremely low birth weight infant populations between 1996-1997 and 1999-2000
Viena Tommiska1, Kirsti Heinonen, Liisa Lehtonen
1National Research and Development Centre for Welfare and Health, Helsinki, Finland. viena.tommiska@hus.fi
Insights
Outcomes for extremely low birth weight infants in Finland remained stable regarding mortality but saw increased neonatal morbidities like respiratory distress syndrome and septicemia. Regional variations in mortality persisted, highlighting the need for further audits.
Area of Science:
- Neonatalogy
- Perinatal Medicine
- Public Health
Background:
- Extremely low birth weight (ELBW) infants represent a vulnerable population with significant short- and long-term health challenges.
- Understanding temporal trends in ELBW infant outcomes is crucial for evaluating and improving perinatal care.
- Finland has a national registry system that facilitates longitudinal studies on ELBW infants.
Purpose of the Study:
- To investigate changes in the outcomes of extremely low birth weight infants born in Finland between two distinct periods in the late 1990s.
- To identify any temporal trends in mortality and major morbidities among ELBW infants.
- To examine regional variations in outcomes within Finland.
Main Methods:
- A national cohort study included all infants with a birth weight under 1000 grams born in Finland during 1996-1997 and 1999-2000.
- Data were collected from a national ELBW infant research register, including perinatal and follow-up information.
- Cerebral palsy and visual impairment data were obtained from hospital records and national registers.
Main Results:
- No significant changes in prenatal, perinatal, neonatal, or postneonatal mortality rates were observed between the two periods (survival rates: 40% vs 44%).
- Incidence of respiratory distress syndrome and septicemia increased, as did overall intraventricular hemorrhage, though severe grades (3-4) did not change.
- Rates of oxygen dependency, severe retinopathy of prematurity, cerebral palsy, and severe visual impairment remained stable.
Conclusions:
- While overall mortality for ELBW infants in Finland did not change significantly in the late 1990s, certain neonatal morbidities showed an increase.
- Persistent regional differences in mortality were noted, suggesting the need for further investigation into causal factors.
- Long-term follow-up studies of geographically defined cohorts are essential for reliable outcome assessment and to guide improvements in perinatal care.
Objective:
Our goal was to investigate whether outcome in extremely low birth weight infants changes over time in Finland.
Patients And Methods:
All infants with a birth weight <1000 g born in Finland in 1996-1997 and 1999-2000 were included in the study. Perinatal and follow-up data were collected in a national extremely low birth weight infant research register. Data concerning cerebral palsy and visual impairment were obtained from hospitals, the national discharge, and visual impairment registers.
Results:
A total of 529 and 511 extremely low birth weight infants were born during 1996-1997 and 1999-2000. No changes were detected in prenatal, perinatal, neonatal, and postneonatal mortality rates between the periods. The survival rates including stillborn infants were 40% and 44%. The incidence of respiratory distress syndrome and septicemia increased from 1996-1997 to 1999-2000 (75% vs 83% and 23% vs 31%). The overall incidence of intraventricular hemorrhage increased (29% vs 37%), but the incidence of intraventricular hemorrhage grades 3 through 4 did not (16% vs 17%). The rates of oxygen dependency at the age corresponding with 36 gestational weeks, retinopathy of prematurity stages 3 to 5, cerebral palsy, and severe visual impairment did not change. Mortality remained higher in 1 university hospital area during both periods compared with the other 4 areas, but no regional differences in morbidity were detected during the later period.
Conclusions:
No significant changes were detected in birth or mortality rate in extremely low birth weight infants born in Finland during the late 1990s, but some neonatal morbidities seemed to increase. Regional differences in mortality were detected in both cohorts. Repeated long-term follow-up studies on geographically defined very preterm infant cohorts are needed for establishing reliable outcome data of current perinatal care. Regional differences warrant thorough audits to assess causalities.
