Temporal trends of intraventricular hemorrhage of prematurity in Nova Scotia from 1993 to 2012.

OBJECT Intraventicular hemorrhage (IVH) and posthemorrhagic hydrocephalus (PHH) are common in premature newborns. The epidemiology of these conditions has been described, but selection bias remains a significant concern in many studies. The goal of this study was to review temporal trends in the incidence of IVH, PHH, and shunt surgery in a population-based cohort of very preterm infants with no selection bias. METHODS All very preterm infants (gestational age ≥ 20 and ≤ 30 weeks) born from 1993 onward to residents of Nova Scotia were evaluated by the IWK Health Centre's Perinatal Follow-Up Program, and were entered in a database. Infants born to residents of Nova Scotia from January 1, 1993, to December 31, 2012, were included in this study. The incidences of IVH, PHH, and shunt surgery were calculated, basic demographic information was described, and chi-square test for trends over time was determined. RESULTS Of 1334 successfully resuscitated very preterm infants who survived to their initial screening ultrasound, 407 (31%) had an IVH, and 149 (11%) had an IVH Grade 3 or 4. No patients with IVH Grade 1 or 2 developed PHH. The percentage of very preterm infants with IVH Grade 3 or 4 has significantly increased over time (p = 0.013), as have the incidence of PHH and shunt surgery (p = 0.001 and p = 0.011, respectively) in infants with Grade 3 or 4 IVH. The proportion of patients with PHH receiving a shunt has not changed over time (p = 0.813). CONCLUSIONS The increasing incidence of high-grade IVH-and PHH and shunt surgery in infants with high-grade IVH-over time is worrisome. This study identifies a number of associated factors, but further research to identify preventable and treatable causal factors is warranted.