An African American male infant born at 23 6/7 weeks gestation via vaginal delivery with APGAR scores of 7 and 7 at 1 and 5 minutes, respectively, was intubated shortly after delivery. An echocardiogram showed a small patent ductus arteriosis and a small patent foramen ovale with left to right shunting. The patient’s initial hospital course was complicated by necrotizing enterocolitis for which he was treated with a Penrose drain and a course of intravenous (IV) piperacillin/tazobactam. On his second day of life, an ultrasound of the brain showed grade III bilateral intraventricular hemorrhage (IVH) without ventriculomegaly. Over the course of the next few days, his head circumference increased each day, and his fontanelle became full with splayed sutures. A follow-up ultrasound of the brain demonstrated significant ventriculomegaly that had not been present on the initial ultrasound (Figure 28-1).
A. Initial ultrasound of the brain of a 2-day-old male infant. B. Follow-up ultrasound.
Intraventricular hemorrhage of prematurity
What is the incidence of IVH in premature infants, and what are the causes?
IVH is a challenging problem for physicians caring for premature infants. Approximately 45% of neonates born before 30 weeks gestation with a low birth weight (≤ 1500 g) have IVH.1 Several studies have shown that the incidence of IVH decreases with increasing gestational age and birth weight.2
In full-term infants, causes of IVH include spontaneous hemorrhage from the choroid plexus, tumors, or arteriovenous malformations (AVMs). In premature infants such as the patient described above, the predominant cause of IVH is hemorrhage from the immature germinal matrix.3 The germinal matrix is located in the subependymal region found at the external angle of the lateral ventricles. The germinal matrix reaches its maximal size at 23 weeks gestation, halves in sizes by 32 weeks, almost completely involutes by 36 weeks, and disappears by the 39th week. Risk of hemorrhage corresponds with birth, while the germinal matrix is still present, with the highest risk in infants born at 23 weeks gestation and the lowest risk after 35 weeks. The timing of IVH has a bimodal distribution in which approximately 50% of IVH occurs within 12 hours of birth and 95% by day 4 of life.4,5 Both obstetrical and neonatal causes of ICH in premature infants have been proposed, but IVH in these patients is most likely multifactorial. Possible obstetrical factors include vaginal delivery, amnionitis, and maternal preeclampsia. Potential neonatal factors include respiratory distress syndrome, hypoxia, hypercarbia, and fluctuations in blood pressure.
Efforts to prevent IVH when a low-birth-weight premature infant is born have previously centered around medications such as phenobarbital, vitamin K, antenatal steroids, vitamin E, and indomethacin, each ...