647 - Temporal Patterns and Associated Factors of Intraventricular Hemorrhage in Extremely Preterm Infants

Publication Number: 2631.647

Channing S. Pooley, Tufts University School of Medicine, Charlestown, MA, United States; Hoda El-Shibiny, Brigham's Women Hospital, Boston, MA, United States; Elisa Abdulhayoglu, Brigham & Women's Hospital, Lynnifeld, MA, United States; Mohamed El-Dib, Brigham and Women's Hospital / Harvard Medical School, Boston, MA, United States

Background: Germinal matrix-intraventricular hemorrhage (GMH-IVH) is the most common intracranial hemorrhage in extremely preterm infants born < 28 weeks' gestation and contributes substantially to neonatal morbidity. Although cranial ultrasonography (cUS) is the standard for detecting IVH, the timing of hemorrhage onset remains unclear. At Brigham and Women's Hospital (BWH), routine cUS screening is performed on days of life 1, 3, and 7 in infants < 28 weeks GA.

Objective: This study aims to identify clinical factors associated with timing of IVH onset. Understanding early vs late IVH characteristics may guide prevention and monitoring.

Design/Methods: This is a retrospective cohort study of infants born at < 28 weeks' gestation between January 2016 and December 2024 at BWH. Data were obtained from the Vermont Oxford Network database and electronic medical record review. cUS reports were reviewed for all infants. Infants were classified as grade I-IV, and severe IVH was classified as grade III-IV. Infants with IVH were further categorized by timing: early (diagnosed < 36 hrs), late (defined as no IVH in first cUS and newly diagnosed IVH in cUS >36 hrs), or unknown (no cUS available < 36 hrs). A secondary analysis compared early vs late severe IVH. Continuous variables were analyzed using Mann-Whitney U or Kruskal-Wallis tests, and categorical variables using chi-square or Fisher's exact tests.

Results: Among 382 infants born at < 28 weeks' gestation, 167 (44%) developed IVH. Of these, 80 (21%) had severe (grade III-IV) IVH. Among infants with IVH, 78 (48%) were classified as early ( < 36 hrs), 70 (42%) as late (>36 hrs), and 24 (14%) as of unknown timing. Vaginal delivery was significantly more frequent in the early IVH group (44% vs 19%, p = 0.001). Birth weight trended lower in the late IVH group (p = 0.078). In the subgroup with severe IVH, PDA was more common in the early cases (p=0.026) and pneumothorax was more common among late cases (p = 0.019). No significant differences were seen between early and late IVH groups in gestational age or other perinatal factors.

Conclusion(s): Vaginal delivery and PDA were associated with early-onset IVH, while pneumothorax was associated with late-onset IVH. Lower birth weight trended toward late hemorrhage. These findings suggest that both delivery factors and neonatal management may influence the timing of IVH in extremely preterm infants. Pneumothorax was more common in late severe IVH, implicating respiratory factors in delayed hemorrhage. Further study is needed to determine if these associations reflect illness severity, practice patterns, or modifiable risk factors.

Table 1: Demographic and Clinical Characteristics of Cohort: Early IVH <36hrs vs Late IVH >36hrs
Categorical variables compared using chi-square or Fisher's exact test; continuous variables compared using Wilcoxon rank-sum test. p < 0.05 considered significant. GM/IVH, germinal matrix/intraventricular hemorrhage; GA, gestational age; DR, delivery room; ETT, endotracheal tube; BPD, bronchopulmonary dysplasia; ROP, retinopathy of prematurity; PVL, periventricular leukomalacia; GI, gastrointestinal; LOS, length of stay. Data presented with * are statistically significant.

Table 2: Demographic and Clinical Characteristics of Severe IVH Cohort: Early IVH <36hrs vs Late IVH >36hrs
Categorical variables compared using chi-square or Fisher's exact test; continuous variables compared using Wilcoxon rank-sum test. p < 0.05 considered significant. GM/IVH, germinal matrix/intraventricular hemorrhage; GA, gestational age; DR, delivery room; ETT, endotracheal tube; BPD, bronchopulmonary dysplasia; ROP, retinopathy of prematurity; PVL, periventricular leukomalacia; GI, gastrointestinal; LOS, length of stay. Data presented with * are statistically significant.