The impact of malnutrition in premature infants on hospital length of stay: A retrospective study in a metropolitan neonatal intensive care unit.

Abstract

Background: The importance of nutrition for the preterm infant is clear, as providing both the appropriate quality and quantity of nutrition to premature infants has been shown to influence infant growth, morbidity, and neurodevelopment outcomes. Nutrition is a lifesaving and life-sustaining intervention in the neonatal intensive care unit (NICU). Therefore, identifying, preventing, and resolving malnutrition in the NICU are all necessary to provide optimal care to the preterm infant. Identifying malnutrition within the first 28 days of life can discern infants struggling to maintain adequate growth and development and having a higher-than-average risk of a longer length of stay (LOS). Addressing malnutrition in the NICU and reducing LOS for these infants dramatically impacts their health outcomes, family distress and decreases the financial burdens of a lengthy stay in the NICU. This study aimed to identify the impact of a malnutrition diagnosis on the 28th day of life on the overall LOS of the subjects. Methods: The records of 53 patients with birth weight > 600 grams < 2500 grams, 24 weeks to < 37 weeks gestational age (GA), > 27-day LOS admitted to the NICU from July 2024 to December 2024 were included in the retrospective chart review. The charts for preterm malnutrition were reviewed for the six malnutrition indicators, including decline in weight for age z score, weight gain velocity, nutrient intake, days to regain birth weight, linear growth velocity, and decline in length for age z score. A final summary malnutrition category was assigned to each patient: no malnutrition, mild malnutrition, moderate malnutrition, or severe malnutrition. The summary was further defined as not having malnutrition or having malnutrition for the final statistical review. Analysis of not having malnutrition and having malnutrition with mean LOS was analyzed using a t-test: two samples assuming unequal variances for statistical significance. Results: Using the malnutrition classification criteria, the overall prevalence of malnutrition was (n=28, 53%) in the population (n=53), mild malnutrition was (n=19, 36%) and moderate malnutrition was (n=9, 17%). No subjects met the criteria for severe malnutrition. The mean LOS was 49.6 ± days for no malnutrition (n=25, 43%), 57.1±24.2 days for mild malnutrition and 92.3 ± 27.4 days for moderate malnutrition. The mean LOS of the total number of patients that met the malnutrition criteria was 68.4 ± 29.9 days. The mean GA= 29.76 ± 2.8 weeks and the mean birth weight = 1321 ± 472.61 grams. Racial disparities noted in the literature were comparable to the results of this study, the Black/African American (AA) babies were born at smaller birth weights and had a longer LOS. Birth weight class and gestational age in this study followed the literature trends for a longer LOS with the infants having smaller birth weight and born at < 28 weeks gestation. The highest risk of a longer LOS with prenatal risks included chronic hypertension with 61±17.2 days LOS, advanced maternal age with 59±19.9 days LOS, and pregnancies with multiples (twins) with 77.5±52.2 days LOS. The highest risk of complications during pregnancy included problems of the uterus, cervix, or placenta, with 89.3±38.6 days LOS with malnutrition, infections of amniotic fluid or lower genital tract with 80.5±31.5 days LOS with malnutrition, and hypertension developed during pregnancy with 57.6±26.3 days LOS with malnutrition. Preterm complications with the highest LOS included bronchopulmonary dysplasia (BPD) at 90.6±19.6 days LOS, necrotizing enterocolitis (NEC) with 88 days LOS and congenital heart disease (CHD) with 85.8±33.4 days LOS. Statistically comparing the LOS of infants with BPD and malnutrition to all subjects without BPD and with malnutrition, infants with BPD and malnutrition resulted in a higher LOS using the t-test: two-sample assuming unequal variances, (M=90.6±19.6), t(19)= 3.28, p =0.002. The main objective is to determine if malnutrition affects LOS using the t-test: two sample, assuming unequal variances. The t-test results (M=68.4 ± 29.9), t (45) =-2.8, p=0.003 indicate a statistically significant difference in LOS between infants with malnutrition and those without malnutrition. The results suggest that malnutrition affects the length of stay in the NICU. Conclusion: The findings of this small retrospective study indicate that the presence of malnutrition does increase the probability of a longer overall length of stay. Many factors drive the need for a longer stay in the NICU, such as feeding intolerance and other diagnoses mentioned in the research. Many intertwined factors go along with malnutrition in affecting LOS, such as the diagnosis of BPD, which may play a role in increasing LOS and in the development of malnutrition. This research emphasizes the critical role of an interdisciplinary approach in neonatal care. Cumulatively, this work identifies the need for malnutrition assessments to identify neonatal malnutrition within the NICU to guide the multidisciplinary team in meeting the infants' needs for growth and development with reduced required length of stay in the NICU. Malnutrition can impact the bottom-line dollar costs for hospitals and parents, and the social and behavior well-being of the infants’ caretakers. If ignored, that decision will affect the child throughout their life.