[Periventricular leukomalacia and persistent hyperechogenicity: relationship between ultrasound findings and sequelae].

OBJECTIVES: The objective of this study was to know the incidence of periventricular leukomalacia and persistent periventricular echodensities in neonates with a birth weight < 1,500 g and to correlate cranial ultrasound findings with the developmental outcome of these babies at 18 months of corrected age.

PATIENTS AND METHODS: We performed a cohort study of 319 newborns weighing 1500 g or less who were admitted to the Neonatal Intensive Care Unit of "12 de Octubre" Hospital between July 1990 and April 1994. Scans were performed while they were hospitalized and 183 surviving infants were followed up to 18 months of corrected age. Relative risks (rr) and 95% confidence intervals (95% CI) were calculated for sequelae according to neonatal cranial ultrasound abnormalities. Ninety-six infants with normal scans were considered as the control group. Persistent periventricular echodensities were classified as mild, moderate or severe.

RESULTS: The incidence of periventricular leukomalacia was 3% (10/319) and of persistent periventricular echodensites was 11.2% (36/319). The percentage of sequelae was 5% for control infants, 15.6% (rr = 3, CI 95% = 0.94-8.8) for persistent periventricular echodensities, independent of its severity, 50% (rr = 9.7, CI 95% = 2.6-35) for moderate persistent periventricular echodensities and 78% (rr = 15.6, CI 95% = 6-38) for periventricular leukomalacia.

CONCLUSIONS: Periventricular leukomalacia multiplies the number of sequelae by 15. Persistent periventricular echodensities, independent of its severity, does not multiply the number of sequelae significantly. However, moderate persistent periventricular echodensities multiply the number of sequelae by 9.