740 - Bleeding at the edge of viability: Incidence and sequelae of intraventricular hemorrhage in very extreme preterm babies since implementing a Very Extreme Preterm (VEP) program

Publication Number: 2722.740

Kate F. DiNucci, University of Washington School of Medicine, Seattle, WA, United States; Sarah Kolnik, University of Washington - Seattle Children's Hospital, Seattle, WA, United States; Kendell German, University of Washington School of Medicine, Seattle, WA, United States; Cailin White, University of Washington School of Medicine, Seattle, WA, United States; Victoria Quach, University of Washington School of Medicine, Seattle, WA, United States; Kirtikumar Upadhyay, University of Washington School of Medicine, SEATTLE, WA, United States; Tiffany Stanley, University of Washington School of Medicine, Seattle, WA, United States; Niranjana Natarajan, University of Washington School of Medicine, Seattle, WA, United States; Thomas Wood, University of Washington, Seattle, WA, United States; Olivia Moretti, University of Washington School of Medicine, Seattle, WA, United States; Ulrike Mietzsch, University of Washington School of Medicine/ Seattle Children's Hospital, Seattle, WA, United States

Background: Very extreme preterm infants (VEP), those born < 25 weeks (wk) gestational age (GA) or with a birthweight < 500 grams, experience high rates of morbidity and mortality, including intraventricular hemorrhage (IVH). IVH can range from mild to severe and commonly leads to long-term developmental complications and comorbidities. To date, the incidence, severity, and sequelae of IVH in VEPs has not been well documented.

Objective: To determine the incidence and progression of IVH in VEP infants admitted and cared for in a regional VEP program.

Design/Methods: This is a single center cohort study of all VEPs admitted between January 2021 and December 2024 to a high-risk delivery Level IV NICU. Patient demographics, IVH severity, onset, and progression, in-hospital complications and mortality were abstracted. Patients were grouped into no IVH, IVH grade I-II, and IVH grade III-IV. Descriptive analyses were performed.

Results: Of 85 VEPs identified, 15 died prior to cranial ultrasound (CUS) (n=11 22-wks GA, n=2 23-wks, n=2 24-wks) and were excluded. Of the 70 included VEPs, 47.1% had no IVH (33/70), including all 4 VEPs born at 25 wks and < 500g (Figure 1A). Patient characteristics were similar among groups; however, VEPs of younger GA had increased grades of IVH, and those with no IVH or grade I-II IVH were more commonly born via cesarean section than those with grade III-IV IVH (63% and 68% vs 28% p=0.02) (Table 1). For those born at 22, 23, and 24-wks GA, the incidence of any IVH was 73.3% (11/15), 64.0% (16/25), and 38.5% (10/26), and grade III-IV was 53.3% (8/15), 28.0% (7/25), and 11.5% (3/26), respectively (Figure 1B). When assessing laterality, only 4/70 VEPs (6%) experienced a bilateral grade IV and 11/70 (16%) bilateral grade III/IV IVH (Figure 1C). For infants whose initial IVH was less than grade IV, 43.3% (13/30) had progression (Figure 2A). 62.2% (23/37) of infants with IVH reached their worst grade of IVH within seven days of life, and the remaining 37.8% (14/37) progressed to a worse grade after the first week of life (Figure 2B). Posthemorrhagic hydrocephalus and white matter injury were more frequently diagnosed in those with grade III/IV IVH.

Conclusion(s): In this large cohort of VEPs, nearly half of infants had no IVH. A higher grade of IVH was seen in VEPs of lower GA. While the majority of IVH reached its maximal grade within the first week of life, 37.8% experienced later progression. This suggests a prolonged high-risk period beyond the first week after birth in VEP infants and that extended screening may be indicated in this population.

Table 1. Demographics and in-hospital outcomes of all infants and by IVH severity.
Discrete variables represented as N (%). Continuous variables represented as Median (IQR). PROM = preterm rupture of membranes; HELLP = hemolysis, elevated liver enzymes, low platelet count; PVL = periventricular leukomalacia; BPD = bronchopulmonary dysplasia; PDA = patent ductus arteriosus; ROP = retinopathy of prematurity; DOL = day of life.

Figure 1. IVH Incidence and severity.
(A) The worst grade of IVH diagnosed for all infants in the study. (B) The worst grade of IVH diagnosed for infants by gestational age (GA) at birth. (C) Heat map of distribution of IVH grades by side of the brain of infants diagnosed with IVH. Each square represents one diagnosis combination of left and right severity. Color intensity represents number of infants per diagnosis/combination.

Figure 2. IVH progression and timing of worst diagnosis.
(A) Sankey plot of diagnoses of each grade of IVH with progression to more severe grades. (B) The time after birth at which IVH the worst grade of IVH was diagnosed, by GA at birth. BL = bilateral; DOL = day of life; W = week.