[Improved chance of survival for very small premature infants in Switzerland].

Extremely low birthweight infants are attracting increasing attention in the medical literature, mainly in audits from selected hospitals not representative of the entire population of a country. The Swiss Neonatology Group gathered selected data on mortality, morbidity and medical treatment of all liveborn infants weighing between 500 and 999 g at birth for the years 1979-81, 1983-85 and 1989-91. The results were compared and completed with information from the Swiss Office of Statistics. From 1979-81 to 1989-91 the incidence of extremely low birthweight infants increased from 1.3 to 2.2 per thousand livebirths. At the same time the survival rate increased from 23% to 53%, resulting in three times more infants being discharged from hospital in this weight group. The number of days of mechanical ventilation, which is an indicator of intensity of care, increased from 320 days to 1440 days per year. In contrast to mortality, morbidity scarcely decreased within this 12-year period and was still considerable in 1989-91. 57% of the survivors had chronic lung disease and 15% had sepsis. Intracranial hemorrhage was present in 35% of the survivors and 71% of the deaths. Retinopathy was noted in 38% of survivors. These facts, which are representative of the whole of Switzerland, show the increasing medical and economic significance of this patient group. Before the implications of this development can be fully assessed, extremely low birthweight infants must be followed up until adult life.