(1) Failure of Head Circumference Growth, but Not Weight Is Associated with Hemodynamically Significant PDA Exposure Among Preterm Infants Born at Less Than 27 Weeks Gestation

Krista Bergquist, University of Iowa, United States; Melanie C. Morris, University of Iowa, United States; Tarah T. Colaizy, University of Iowa, United States; Susan Carlson, University of Iowa, United States; Patrick J. Mcnamara, University of Iowa, United States; Regan E. Giesinger, University of Iowa, Iowa City, IA, United States

Background: Persistent hemodynamically significant patent ductus arteriosus (hsPDA) following preterm birth results in circulatory disturbance whereby pre-ductal [e.g. brain, heart] circulation is hyper-perfused and post-ductal [e.g. enteric] circulation may be hypo-perfused which may impact growth. hsPDA has been associated with impaired neurodevelopment and literature suggests that both somatic growth and brain volume may be adversely affected; however, these studies typically used aggressive fluid restriction and diuretics.

Objectives: To characterize the association between hsPDA beyond the transitional period (>3 days) and postnatal head circumference (HC) and somatic growth at 6 weeks postmenstrual age.

Design/Methods: A retrospective cohort study of neonates born < 27 weeks gestation, admitted between 11/18-06/21, was conducted. Included patients were screened at < 24h postnatal age, day 5-7 and regularly thereafter until resolution of hsPDA was documented. By clinical practice, hsPDA therapy does not include routine use of diuretics or (occas. mild) fluid restriction. Patients with anasarca, genetic/major anomalies or furosemide therapy were excluded. Patients were classified as hsPDA-exposed patients if the Iowa PDA score [Table 1] was ≥6 during the study period and treatment for PDA was received. Duration and magnitude [mean PDA Score*days exposed] of hsPDA exposure were evaluated. A composite primary outcome of death before 42 days [longest shunt duration] or growth failure [weightHC for age loss >-0.8 z-score] at 423 days. Univariate analysis and logistic regression were performed.

Results: A total of 134/150 eligible patients were included. hsPDA-exposed (n=85) infants had a 3-fold higher risk of the composite outcome compared to controls.[Table 2] Failure of HC, but not somatic growth was more likely in hsPDA exposed patients; specifically, both HC z-score and change in HC z-score were lower. Median PDA duration [20.5 (6.3, 28) vs 13 (3, 28), p=0.14] and median cumulative PDA score [137 (48, 181) vs. 96 (10, 176), p=0.1] were higher among patients with HC growth failure. Binary logistic regression, to adjust the risk of composite outcome for gestational age (GA), revealed an OR of 3.1(1.49,6.6) p=0.003 for PDA exposure and an OR of 0.99 (0.78,1.3) p=0.94 for GA.

Conclusion: Extremely preterm neonates exposed to hsPDA beyond the transitional period have a greater risk of death and failure of HC, but not somatic growth which is independent of gestational age at birth. Further studies into later catch-up growth and nutritional modifiers merit consideration.