Grades I-II intraventricular hemorrhage in extremely low birth weight infants: effects on neurodevelopment.

OBJECTIVE: To quantify the effect of grades I-II intraventricular hemorrhage (IVH) on the neurosensory and cognitive outcomes of extremely low birth weight infants.

STUDY DESIGN: Of 706 extremely low birth weight infants without major malformations admitted to our center from 1992 to 2000, 537 survived to 20 months' corrected age (CA) and had cranial ultrasound studies performed, of whom 490 (91%) had complete neurodevelopmental assessments. Infants with severe cranial ultrasound abnormalities or meningitis were excluded, leaving a population of 362 infants, 258 of whom had a normal cranial ultrasound and 104 had an isolated grade I-II IVH. The groups had similar birth weight (808 vs 801 grams) and gestational age (26.5 vs 26.3 weeks). Outcomes of infants with normal cranial ultrasound were compared with those with grades I-II IVH at 20 months' CA. Outcomes included the Bayley Scales of Infant Development Mental Developmental Index (MDI) and major neurosensory abnormality. Logistic regression was used to assess the effect of grades I-II IVH on outcomes while adjusting for other risk factors.

RESULTS: Extremely low birth weight infants with grades I-II IVH had a significantly lower mean MDI score than infants with normal cranial ultrasound (74 +/- 16 vs 79 +/- 14, P = .006). They had higher rates of MDI <<70 (45% vs 25%; OR, 2.00; 95% CI, 1.20 to 3.30; P = .008), major neurologic abnormality (13% vs 5%; OR, 2.60; 95% CI, 1.06 to 6.36; P = .036), and neurodevelopmental impairment (47% vs 28%; OR, 1.83; 95% CI, 1.11 to 3.03; P = .018) at 20 months' CA, even when adjusting for confounding factors.

CONCLUSIONS: Extremely low birth weight infants with grades I-II IVH have poorer neurodevelopmental outcomes at 20 months' CA than infants with normal cranial ultrasound. Advanced radiologic imaging may indicate additional brain injury associated with grade I-II IVH, which could explain these outcomes.