Mortality and morbidity in extremely preterm infants (22 to 26 weeks of gestation): Austria 1999-2001.

OBJECTIVE

The aim of this retrospective study was to analyze the mortality and morbidity for extremely preterm infants with a gestational age from 22 to 26 weeks. All infants were born in Austria during the years 1999-2001.

METHODS

Data were collected from 16 neonatal intensive care units in Austria. Main outcome criteria were mortality, the rates of chronic lung disease (CLD) and severe retinopathy of prematurity (ROP, stage > or =3) to determine the short-term outcome; the rate of cerebral palsy (CP) at the corrected age of twelve months to assess the long-term outcome.

RESULTS

Overall, 796 preterm infants with a gestational age less than 27 weeks were born in Austria and 581 (73%) were registered as live-born infants. Of those live born, 508 (87%) were analyzed. The mortality rates were 83%, 76%, 43%, 26% and 13% for 22, 23, 24, 25 and 26 weeks' gestation, respectively. The rates of CLD were 33% (22 weeks), 36% (23 weeks), 42% (24 weeks), 31% (25 weeks) and 22% (26 weeks). The rates of ROP of stage > or =3 were 0% (22 weeks), 29% (23 weeks), 23% (24 weeks), 18% (25 weeks) and 10% (26 weeks). The rates of CP at the corrected age of 12 months were 33%, 50%, 33%, 26% and 25% for 22, 23, 24, 25 and 26 weeks' gestation, respectively.

CONCLUSIONS

The results of this national study are in accordance with the international literature: mortality and morbidity increased with decreasing gestational age.