Abstract 205

Aims: To determine the incidence of PVL, to identify associated factors and to evaluate the frequency of neurological abnormality at discharge. Patients and methods: Infants with PVL in Switzerland were systematically registered (Swiss Pediatric Surveillance Unit, Swiss Neonatal Network) over three years (1995 to 1997). They were compared to a control group matched for gestational age.

Results: 40 infants with PVL defined as at least 2 cysts with minimal diameter of 2 mm in the periventricular region were identified. In comparison with the matched controls the infants with PVL had received significantly less frequently antenatal cortocosteroids (44% vs 78%, Event Rate Ratio 0.57, 95% confidence interval 0.38-0.68), they had lower umbilical cord arterial pH and lower Apgar scores; there was a trend to arterial hypotonia and hypocapnia associated with PVL. The infants of the study group needed more often mechanical ventilation or nasal CPAP (92% versus 67%; ERR 1.38, CI 1.07-1.77) and had more often intracranial hemorrhage (39% versus 14%; ERR 2.8, CI 1.13-6.96). 56% of the infants with PVL were considered abnormal at the neurological examination at discharge compared to 28% in the control group.

Conclusions: The incidence of PVL in Switzerland is 0.16? for all newborns and 1.2% for preterm infants with a birth weight less than 1500g. Cranial ultrasonography on infants at risk for PVL is important because 44% of the infants with PVL didn't show neurologic abnormalities at discharge.