Objective: To describe the incidence of developmental impairments (DI) among very low birth weight (VLBW) infants at 24 months' corrected age, born in perinatal centers in 1997-2007, and evaluate their changing prognosis of intact development.
Design: Prospective epidemiological study.
Setting: Follow-up clinics of neonatal centers level III.
Methods: Live birth rate, in-hospital mortality, neonatal morbidity, DI and quality of survival were assessed. Neonatal morbidity was analyzed in periods 2000/2, 2003/5, and 2006/7 by the data of Institute of Health Informatics and Statistics. DI and quality of survival were evaluated in cohorts of VLBW infants born in 1997/9 (period I), 2000/2 (period II), 2003/5 (period III) and 2006/7 (period IV).
Results: Live birth rate of VLBW newborns in 1997-2007 increased in total of 39.5%, in-hospital mortality decreased, significantly in 1997-9 (fall of 10%). Neonatal morbidity, except infections, also declined. Significant decrease in DI-CP and visual impairment, was observed after period II, in category 1000-1499 g of 7/1.5%, in infants <1000 g of 8/7% resp. After period II, the prevalence of impaired children 1000-1499 g decreased of 5%, whereas in category < 1000 g only small decrease of 2% occurred in period III. Number of children without impairment increased gradually in both categories.
Conclusions: The study showed significant increase in surviving VLBW infants, especially in category <1000 g. Increased survival rate at concurrent fall in severe neonatal morbidity (except infections) was not accompanied with worsened prognosis of an intact development.