INFLUENCE OF PRENATAL AND PERINATAL RISK- FACTORS ON THE INCIDENCE AND SEVERITY OF RESPIRATORY-DISTRESS SYNDROME IN PREMATURE NEWBORN-INFANTS

Background Respiratory distress syndrome (RDS) due to surfactant defic iency remains a cause of considerable mortality in the neonatal period . Methods In a retrospective study we analysed the records of 1109 pre mature newborns with a birth weight below 1500 g that were treated on our unit. RDS was assumed if the infants needed mechanical ventilation with oxygen supplementation and the typical radiological signs were p resent on chest x-ray. Results No changes in the incidence of RDS were found during the period of observation. Below 29 weeks gestational ag e 90% of infants suffered from RDS (55% severe RDS grade III or IV). T he incidence was 75% (grade III or IV: 32%) for infants born at 29 and 30 weeks, 48% (grade III or IV: 15%) at 31 and 32 weeks and 33% (grad e III or IV: 6%) for neonates born at 33 weeks of gestation. Using a l ogistic regression analysis model the following parameters wire found to increase the risk for RDS significantly (p < 0.05): no prenatal ste roid treatment, Cesarian section, male gender, APGAR at 5 min < 7, met abolic acidosis (base excess less than or equal to -6 mval) and rectal temperature <36 degrees C on admission. Following gestosis, insuffici ency of the placenta and premature rupture of membranes a decrease in the incidence of RDS was observed. Conclusion We conclude that althoug h some risk factors for RDS will be difficult to exclude (e.g. materna l disease, gender) the incidence and severity of RDS can be reduced by measures like maternal antenatal steroid treatment. Perinatal asphyxi a (low APGAR values and/or acidosis) and hypothermia should be avoided , as these conditions increase the relative risk for developing RDS.