PC1050: Duration of Hypotension and Intraventricular Hemorrhage in Premature Infants

Background: Intraventricular hemorrhage (IVH) is a major neonatal complication of infants born before 26 weeks gestation. Factors that cause fluctuation in cerebral blood flow including hypotension, especially during the first week of life, are risks for IVH. Understanding the relationship between hypotension duration and IVH severity could help guide our management of a hypotensive premature infant, especially when considering timing of intervention.

Methods: We performed a single-center retrospective cohort study. All consecutive liveborn infants with < 26 weeks completed gestation between the years 2013 and 2020 were eligible for inclusion. Infants with multiple severe congenital anomalies, brain anomalies, severe congenital heart disease, death before head ultrasound, and outborn infants were excluded. Hourly mean arterial pressures (MAP) for the first 72 hours of life were extracted for each infant. Data for duration of hypotension was collected based on two commonly accepted definitions of hypotension: MAP below gestational age (MAP< GA) and MAP below 30 (MAP < 30). The diagnosis and severity of IVH was assessed using head ultrasound at 7 days of life. Chi-squared test or Fisher’s exact test was used to analyze categorical variables and independent sample T-test for continuous variables. We performed a multivariable logistic regression analysis to assess crude and adjusted associations between outcomes and predictive factors.

Results: 198 infants met criteria for inclusion. Of those, 59 (29%) developed IVH by one week of life. MAP less than gestational age was observed in 56% of infants while 95% had hypotension defined as MAP less than 30. Infants that were hypotensive for longer than 60 minutes had higher severity of IVH (p=0.018). In our univariate analysis, Cesarean section delivery, five-minute APGAR score < 7, prolonged rupture of membranes, and chorioamnionitis were significantly associated with hypotension (MAP < GA). A multivariable logistic model revealed hypotension duration longer than 60 minutes, five-minute APGAR score < 7, and mean gestational age to be independently predictive of IVH severity.

Conclusion: Hypotension (defined as MAP< GA) for longer than 60 minutes is associated with higher severity of IVH.