Thesis supervisor:
Senior Lecturer Heili Varendi, University of Tartu
Senior Research Fellow Anneli Kolk, University of Tartu
Opponent:
Uwe Ewald, Uppsala University, Sweden
Summary:
Advances in perinatal care have improved the survival of VLGA (born <32 weeks' gestation) infants dramatically, but these infants remain at substantial risk for a wide spectrum of long-term morbidities. Therefore, it is mandatory that any assessment of quality of care for VLGA infants includes the long-term outcome.
The aims of the studies were to describe outcome and acute respiratory morbidity of VLGA infants in Estonia, to identify risk factors for adverse outcome, and to benchmark the quality of perinatal services in the country.
A nationwide prospective cohort study comprised 360 live-born VLGA infants born in Estonia in 2007-2008. Perinatal data were collected to the neonatal research register. A historical cohort of 264 VLGA infants born in 2002-2003 was selected for analysis of changes in the short-term outcome. A sub-cohort of 155 surviving VLGA infants born in 2007 was compared with a matched full-term control group at 2 years of corrected age. The infants underwent physical, neurological, and developmental assessment. Acute respiratory morbidity was identified by parental interviews.
The survival until discharge increased significantly (78% in 2002-2003 vs 85% in 2007-2008) with proactive perinatal management and less invasive neonatal care and without concomitant increases in neonatal morbidity. However, the morbidity rates were higher when compared with comparable data from high income countries. At follow-up, neurodevelopmental impairment was noted in 12% of VLGA infants, with 8% affected by cerebral palsy, 5% with cognitive delay, and 10% with language delay. The mean Cognitive, Language, and Motor Composite Scores assessed using the Bayley-III scales were in VLGA group in excess of 0.5 SD lower than in full-term infants. Wheezing during respiratory infections and somatic growth failure were significant problems among VLGA infants.
Major neonatal morbidities, predictive of poor long-term outcome, were the main risk factors for adverse outcomes.
The results showed that for VLGA infants in Estonia, the survival is comparable and the rates of early morbidities and impairments at 2 years are partly higher when compared to similar studies from high income countries. The challenge for perinatal services in Estonia is to reduce neonatal morbidity of VLGA infants without compromising their survival.