Limits of viability: chances of survival and outcome

The borderline for viability has been further reduced in the last decade in the developed countries; there are reports of surviving infants after 22 w eeks gestation. In the data of large neonatal collaboration networks, the 5 0th percentile for survival is in the range of 24-25 weeks. Procedural impr ovements in perinatology and methodological changes in outcome studies prec lude an extrapolation of older outcome results for this new generation of e xtremely premature infants. The first short-term morbidity data disclose a subnormal development or serious sequelae in more than 50% of survivors, wh ile longterm outcome studies are obviously lacking. Neonatologists' modes of practice worldwide also have an impact on the morb idity and mortality of such infants. In addition to accepted standards of c are of pregnancies at risk for premature birth in a perinatal center, a str ong involvement of parents in the decision making regarding resuscitation o f extremely premature, technology-dependent infants is called for. Every pe rinatal center caring for extremely premature infants has an obligation to implement a follow-up program or to participate in an outcome study network .