453 - Postnatal Maximal Weight Loss, Fluid Administration, and Outcomes in Extremely Preterm Newborns

Poster Number: 453
Publication Number: 453.335

Gregory C. Valentine, University of Washington, Tacoma, WA, United States; Krystle M. Perez, University of Washington School of Medicine, Snohomish, WA, United States; Tommy Wood, University of Washington School of Medicine, Seattle, WA, United States; Dennis E. Mayock, University of Washington, LAKE FOREST PARK, WA, United States; Bryan A. Comstock, University of Washington, Seattle, WA, United States; Mihai Puia-Dumitrescu, University of Washington School of Medicine, Seattle, WA, United States; Patrick Heagerty, University of Washington, Seattle, WA, United States; Sandra E. Juul, University of Washington, Seattle, WA, United States

Background: Physiologic weight loss is important in the fetal-to-neonatal transition, but the threshold at which physiologic weight loss becomes pathologic, if any, remains uncertain. While studies have evaluated the impact of fluid administration or weight loss on adverse outcomes, there is a paucity of literature assessing both factors on outcomes, noting one may influence the other.

Objective: We sought to determine effects of total fluid administration (TFA) and weight loss patterns in the first week after birth on in-hospital neonatal outcomes among a contemporary cohort of extremely preterm (EP) neonates.

Design/Methods: We implemented a retrospective, sub-study of the Preterm Epo Neuroprotection Trial (PENUT) evaluating maximal weight loss (MWL) and average TFA in the first week after birth, and their association with neonatal mortality and in-hospital morbidities. Outcome analyses were based upon 3 separate MWL categories: high (>15%), intermediate (5-15%), and low ( < 5%, including weight gain); and three averaged TFA categories: low ( < 120 mL/kg birthweight/day), intermediate (120-150 mL/kg birthweight/day), and high (>150 mL/kg birthweight/day). Outcomes included bronchopulmonary dysplasia, grade 2b or 3 necrotizing enterocolitis (NEC), patent ductus arteriosus (PDA) requiring surgical intervention, intracranial hemorrhage at days 7-9 after birth, and mortality prior to discharge.

Results: Among 883 EP neonates, MWL between 5-15% from birthweight was associated with decreased adjusted odds of NEC compared to MWL >15% (OR 0.49, 95% CI 0.25-0.98) (Table 1). Average TFA >150 mL/kg birthweight/day over the first 7 days after birth was associated with increased adjusted odds of NEC (OR 3.22, 95% CI 1.40-7.42) and PDA requiring surgery (OR 2.14, 95% CI 1.10-4.15) compared to TFA < 120 mL/kg birthweight/day (Table 2). Neonates born at 24 weeks’ gestation had a mean (SD) MWL of 11.2% (7.8%) compared to 9.4% (5.7%) in those born at 27 weeks’ gestation (Figure 1). The median day of MWL for all included neonates was day 3 (Figure 1). Increasing total fluids and higher maximal weight loss was not associated with BPD in our adjusted analysis. Similarly, mortality was similar in all groups.Conclusion(s): MWL between 5%-15% is a potentially optimal window of weight loss. Increasing average TFA is associated with adverse neonatal outcomes. Prospective studies evaluating promotion of MWL between 5-15% and relationship to outcomes in extremely preterm newborns are needed.
Table 1. Examining maximal weight loss categories and odds of in-hospital outcomes of infants surviving at least 7 days including adjustment for average total fluid administration.
Table 2: Examining average total fluid administration categories and odds of in-hospital outcomes of infants surviving at least 7 days including adjustment for maximal weight loss percentage.