Objective: To describe obstetric intervention for extremely preterm births in ten European regions and assess its impact on mortality and short term morbidity.
Design: Prospective observational cohort study.
Setting: Ten regions from nine countries participating in the 'Models of Organising Access to Intensive Care for Very Preterm Babies in Europe' (MOSAIC) project.
Population: All births from 22 to 29 weeks of gestation (n = 4146) in 2003, excluding terminations of pregnancy.
Methods: Comparison of three obstetric interventions (antenatal corticosteroids, antenatal transfer and caesarean section for fetal indication) rates at 22-23, 24-25 and 26-27 weeks to that at 28-29 weeks and the association of the level of intervention with pregnancy outcome.
Main outcome measures: Use of antenatal corticosteroids, antenatal transfer and caesarean section by two-week gestational age groups as well as a composite score of these three interventions. Outcomes included stillbirth, in-hospital mortality and intraventricular haemorrhage (IVH) grades III and IV and/or periventricular leucomalacia (PVL) and bronchopulmonary dysplasia (BPD).
Results: There were large differences between regions in interventions for births at 22-23 and 24-25 weeks. Differences were most pronounced at 24-25 weeks; in some regions these babies received the same care as babies of 28-29 weeks, whereas elsewhere levels of intervention were distinctly lower. Before 26 weeks and especially at 24-25 weeks, there was an association between the composite intervention score and mortality. No association was observed at 26-27 weeks. For survivors at 24-25 weeks, the intervention score was associated with higher rates of BPD, but not with IVH or PVL.
Conclusions: There are large differences between European regions in obstetric practices at the lower limit of viability and these are related to outcome, especially at 24-25 weeks.