Intraventricular Hemorrhage and Survival, Multimorbidity, and Neurodevelopment.

Importance: Intraventricular hemorrhage (IVH) has proven to be a challenging and enduring complication of prematurity. However, its association with neurodevelopment across the spectrum of IVH severity, independent of prematurity, and in the context of contemporary care remains uncertain. Objective: To evaluate national trends in IVH diagnosis and the association with survival and neurodevelopmental outcomes at 2 years of age. Design, Setting, and Participants: This whole-population cohort study was conducted using data from the UK National Neonatal Research Database. Infants born at less than 29 weeks' gestation with any grade of IVH between January 2013 and December 2019 in England were included and matched with controls. Data analysis occurred from November 2023 to June 2024. Exposure: IVH grades 1 to 4 (Papile classification). Main Outcomes and Measures: The primary outcome was survival without severe neurodevelopmental impairment (NDI) at 2 years' corrected age including severe delays (inability to understand or use >5 words or signs; being unable to walk, sit, or use hands; blindness; or uncorrectable hearing impairment). Secondary outcomes included gross and fine motor function, receptive and expressive communication, vision, hearing, and overall developmental progress. Outcomes were derived from clinician-entered data and analyzed using multiple logistic regression. Results: Between 2013 and 2019, of 26 756 infants born at less 29 weeks' gestation in England, 8461 received a diagnosis of IVH (5570 low-grade and 2891 high-grade, and 8328 were included in the study. Overall, 5519 included infants had low-grade IVH with a median [IQR] gestational age of 26 (25-27) weeks, of which 2477 (48.88%) were male. Of the 2809 included infants with high-grade IVH, the median (IQR) gestational age was 25 (24-26) weeks and 1710 (60.88%) were male. The mean (SD) incidence of high-grade IVH (108 [6.7] per 1000 live extremely preterm births) and low-grade IVH (208 [10.4] per 1000 live extremely preterm births) increased between 2013 and 2019, although this did not reach statistical significance for high-grade IVH. Survival without severe NDI decreased significantly after high-grade IVH (a 74% reduction; aOR, 0.26; 95% CI, 0.22-0.31), and to a lesser extent after low-grade IVH (a 12% reduction; aOR, 0.88; 95% CI, 0.79-0.98). Although low-grade IVH was associated with functional impairments, most survivors, 2283 of 4379 infants (52.15%), had no NDI, and the association with NDI was accounted for by grade 2 IVH. Decreased survival without severe NDI was observed with increasing grade of IVH, decreasing gestation, bilateral compared to unilateral injuries, and increasing morbidity count (severe retinopathy of prematurity, bronchopulmonary dysplasia, and surgical necrotizing enterocolitis). Impairments in gross motor function and communication were common, especially among those with high-grade IVH (with prevalences of 44.55% [715 of 1605 infants] and 48.91% [784 of 1603 infants], respectively). Conclusions and Relevance: In this cohort study, IVH was highlighted as a persistent issue with substantial neurodevelopmental implications despite advances in care. This study offers useful data for counseling families; however, follow-up to school age is necessary to grasp the full impact of these injuries on children's lives.