Preterm twin gestation and cystic periventricular leucomalacia

Objective: To identify risk factors for the development of cystic periventricular leucomalacia (PVL) in twin gestation. Design: Retrospective case-control study. Setting: Tertiary care university hospital, Department of Paediatrics, Division of Neonatology, Graz, Austria. Patients: Preterm twin gestations with one sibling having developed cystic PVL, diagnosed by ultrasound scans, compared with their co-twins without PVL, in hospital between 1988 and 2000. Main outcome measures: Perinatal and postnatal risk factors for the development of PVL. Results: Eighteen preterm twin gestations were included. Monochorionicity was evident in 47% of the pregnancies, and twin to twin transfusion syndrome occurred in two cases (11%). Fetal distress correlated inversely with PVL (15% v 53%, p  =  0.019, relative risk (RR)  =  2.057, 95% confidence interval (CI)  =  1.067 to 3.968). Hypocarbia with PCO₂ levels below 30 mm Hg (4 kPa) was diagnosed in 29% of the cases compared with 6% of the controls (p  =  0.038, RR  =  1.944, 95% CI  =  1.113 to 3.396). There were no significant differences between groups with regard to premature rupture of the membranes, early onset infection, respiratory distress syndrome, mechanical ventilation, arterial hypotension, persistent ductus arteriosus, and hyperbilirubinaemia. Asphyxia was only evident in three controls. Three infants died and another three were lost to follow up. None of the cases compared with 62% of the controls were diagnosed as having developed normally (p < 0.001), and 14 cases (82%) compared with two controls (15%) developed cerebral palsy (p < 0.001). Conclusion: Hypocarbia was the only risk factor strongly associated with cystic PVL. The general outcome of the infants was poor.