Risk factors for intraventricular hemorrhage in a birth cohort of 3721 premature infants

In our study we determined possible risk factors for intraventricular hemorrhage grade III to IV (IVH) based on a regional German neonatal data base and tried to build a logistic-regression model to predict the risk of IVH according to gestational age.

We identified 3721 premature infants, 22 to 36 completed weeks of gestational age, born from 1994 through 1997. 136 (3.7%) IVH were diagnosed sonographically. 60 (44%) infants with IVH died. We examined the following variables as risk factors for IVH: gestational age, sex, blood pH of 7.2 or less, body temperature of 35 degrees C or less, multiple birth, small-for-gestational age, intubation after birth, transport to another hospital.

In the full logistic regression model sex, blood pH of 7.2 or less, multiple birth, and small-for-gestational age were not associated with a significant risk of IVH. Body temperature of 35 degrees C or less was associated with an increased risk of IVH (adjusted odds ratio, 1.92; 95% confidence interval, 1.09 to 3.40). Intubation after birth increased the risk of IVH in neonates under 28 weeks of gestational age (OR, 3.72; 95% CI, 1.65 to 8.38) only to a moderate extent, but significantly in neonates 32 to 36 weeks of gestational age (OR, 16.51; 95% CI: 7.35 to 36.18). The risk of IVH was mainly related to gestational age. Neonates delivered before 28 weeks of gestation (OR, 75.72; 95% CI, 46.14 to 124.30) faced the highest risk of IVH. Transport to another hospital was connected with an increased risk of IVH regardless of gestational age (adjusted OR, 1.95; 95% CI, 1.07 to 2.56).

The frequency of IVH could be reduced significantly, if extremely premature infants, the vast majority of patients suffering from IVH, did not have to be transferred postnatally to another hospital.