TOP 69 - Incidence and Severity of Intraventricular Hemorrhage by Gestational Week in At-Risk Infants: A Contemporary Multicenter Cohort Study

Publication Number: 3800.TOP 69

Isabelle M. Kiefaber, University of Washington School of Medicine, Seattle, WA, United States; Mihai Puia-Dumitrescu, 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; Kendell German, University of Washington School of Medicine, Seattle, WA, United States; Sarah E. Kolnik, University of Washington - Seattle Children's Hospital, Seattle, WA, United States; Samia Aleem, Duke University School of Medicine, Durham, NC, United States; Rachel G. Greenberg, Duke Clinical Research Institute, Durham, NC, United States; Veeral Tolia, Pediatrix, Dallas, TX, United States; Janessa Law, University of Washington School of Medicine, Seattle, WA, United States

Background: Infants born ≤30 0/7 weeks’ gestation and those with very low birth weight (VLBW, < 1500 g) are at highest risk for developing intraventricular hemorrhage (IVH). Advances in perinatal and neonatal care—including antenatal corticosteroids, delayed cord clamping, noninvasive respiratory support, and early breast milk feeding—have reduced IVH incidence, particularly among infants ≥28 0/7 weeks. Current American Academy of Pediatrics (AAP) guidelines recommend serial cranial ultrasounds (CUS) for all infants < 30 0/7 weeks’ gestation, but these recommendations are based on studies predating recent improvements in neonatal care with none addressing 29 week infants specifically. The contemporary incidence and severity of IVH in infants born from 29 0/7 to 29 6/7 weeks remain poorly defined.

Objective: To review IVH rates in all infants ≤30 0/7 weeks’ gestation and infants born < 32 weeks with birthweight < 1500 g, and to compare the rates and severity of IVH in infants born 29 0/7 – 29 6/7 weeks’ gestation to infants in the 28 0/7 – 28 6/7 and 30 0/7 – 30 6/7 week’s gestational age groups in the modern era, potentially informing future refinement of CUS screening recommendations.

Design/Methods: We are conducting a retrospective cohort study using the Pediatrix BabySteps Clinical Data Warehouse, which aggregates de-identified data from more than 300 U.S. NICUs and qualifies as exempt of Institutional Board Review. Eligible infants were born between January 1, 2010, and December 31, 2023, at ≤30 6/7 weeks’ gestation or < 32 weeks with birthweight < 1500 g. Infants with genetic diagnoses or complex congenital heart disease were excluded. Maternal and neonatal variables—including prenatal steroid exposure, delivery mode, Apgar scores, ventilatory support, hemodynamic instability, and infection—were collected. IVH grade, periventricular leukomalacia, and post-hemorrhagic ventricular dilation were obtained from serial CUS reports. Summary statistics will describe IVH incidence and severity by completed gestational week at birth. Planned analyses include Chi-square and Wilcoxon tests to compare infants with and without IVH risk factors (e.g., sepsis, PDA treatment, vasopressor use). Multivariable logistic regression will assess independent associations between gestational week and IVH occurrence or grade. Data extraction and cleaning are complete for more than 85,305 infants eligible for this study from 350 sites. Statistical analyses are underway, with preliminary results expected by January 2026.