Many regional, national or international neonatal networks, such as the Vermont Oxford Network or the EuroNeoNet, collect data on the outcome of very low birth weight infants (VLBWI) for benchmarking in order to improve quality of care. Whereas physicians use these data to assure quality of the outcomes of interest and to target interventions and new treatments, data collected on a national level may be used by political or healthcare organisations to reorganise their healthcare system. Furthermore, pregnant mothers with threatened preterm delivery may use data from individual units to decide at which perinatal centre they want treatment to be provided. Specifically, pregnant mothers and their families may want to know the chances of survival to discharge and the risk for morbidity as both outcomes may affect their life dramatically. This aspect is extremely important in the situation of threatened preterm delivery at the threshold of viability for decision making on a provision of life support.

The obstetrical approach at the lower limit of viability may vary widely. In a prospective study comparing 10 different regions across Europe, some key obstetric interventions such as administration of corticosteroids, antenatal transfer to a level III perinatal centre and caesarean section for fetal reasons were provided very differently for pregnant mothers and their preterm babies at the threshold of viability.1 Furthermore, the rate of births declared as stillbirths were more than 10 times …