Cerebellar hemorrhage in the preterm infant: Ultrasonographic findings and risk factors

Cerebellar hemorrhage (CBH) in premature infants is increasingly diagnosed secondary to improved neuroimaging techniques and survival of very small preterm infants. Information is limited, however, on the incidence, topography, and risk factors for CBH in the preterm infant. Objectives. To define the incidence of CBH in preterm infants diagnosed by neonatal cranial ultrasound ( US), describe the sonographic features of CBH, and identify maternal and perinatal risk factors associated with this lesion. Methods. A systematic electronic database search identified preterm infants born 1998-2002 with US diagnosis of CBH. For 35 cases of CBH we double-matched ( according to gestational age, gender, and year of birth) 70 preterm controls with normal cranial USs and performed detailed medical-record reviews for both patients and controls. Results. Unilateral CBH was seen in 25 patients (71%), vermian hemorrhage was seen in 7 (20%), and combined bihemispheric and vermian hemorrhage was seen in 3 (9%). Isolated CBH occurred in 8 patients (23%); the remaining infants had associated supratentorial lesions. The incidence of CBH in preterm infants weighing < 750 g at birth showed significant increase over the study period. Univariate analyses identified maternal, intrapartum, and early postnatal hemodynamic risk factors; multivariate regressions indicated that emergent caesarian section, patent ductus arteriosus, and lower 5-day minimum pH independently increased the odds of CBH. Neonatal mortality and morbidity were significantly higher among patients with CBH compared with preterm controls. Conclusions. CBH is an important complication of extreme preterm birth and has been underrecognized in surviving preterm infants. Predictors of CBH seem to be multifactorial and include combined maternal, intrapartum, and early postnatal factors.