Background The EXPRESS study has shown favourable peri-and neonatal outcomes of extremely preterm infants (EPT, < 27weeks) in Sweden compared with similar studies.
Objective To determine whether there are differences in peri- and neonatal outcomes in spite of favourable national rates and whether outcomes can be related to regional differences in the use of perinatal interventions.
Methods Population-based prospective study of all EPT children born in Sweden from April1, 2004, to March 31, 2007. Of 1011 births, 707 were born alive and 497 survived to one year. Each region was assigned a perinatal activity score (PAS) based on the rate of selected perinatal interventions. Mortality rates were calculated, adjusted for background factors and related to PAS.
Results There were few regional differences in demographic background data. PAS varied from 74 to 100 (median 82) between regions. When 3 regions with the highest PAS (median 98) were compared with 4 regions with lower PAS (median 79), the following adjusted odds ratios (AOR) were found for infants born at 22–26 weeks: Perinatal death, AOR 0.6 (95%CL 0.4–0.8), infant mortality 0.6 (95% Cl 0.4–0.9). There was no increase in the odds for survival with severe neonatal morbidity; AOR 0.7 (95% Cl 0.5–1.0). When stratified by gestational age, increased survival was confined to infants born at 22–24 weeks. Regional differences were nullified when early deaths (< 12 hours) were excluded.
Conclusions There are differences in peri- and neonatal outcomes between regions in Sweden which can be explained by the intensity of perinatal interventions.