Association of early fluid load with serious complications invery/extremely low birth weight preterm infants

Objective To investigate the relationship between early postnatal fluid load and severe complications such as bronchopulmonary dysplasia (BPD), neonatal necrotizing enterocolitis (NEC), brain injury in premature infants (BIPI), hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants with very low and extremely low birth weight. Methods A total of 147 preterm infants with birth weight less than 1 500 g and gestational age less than 32 weeks who were hospitalized in the Neonatal Intensive Care Unit of the Affiliated Hospital of Xuzhou Medical University from August 2018 to August 2021 were selected as research subjects. According to the occurrence of diseases, they were divided into two groups: an experimental group and a control group. A case-control retrospective study was conducted to compare the differences in fluid intake between the experimental groups (including the BPD group, the NEC group, the BIPI group, and the hsPDA group) and the control group on days 1, 2, 3, and 4 after birth and the total fluid intake in the first four days. A receiver operating characteristic (ROC) curve was plotted to predict the optimal daily fluid intake and total fluid intake in the first four days after birth for preterm infants with very low and extremely low birth weight. Results The total fluid intake in the BPD group, NEC group, BIPI group and hsPDA group on days 1, 2, 3 and 4 and the first four days after birth were higher than those in the control group, with statistical differences (P<0.05). In the NEC group, the cut-off values of fluid intake on days 1, 2, 3 and 4 and the first four days were 98.9 ml/kg, 123.5 ml/kg, 131.3 ml/kg, 147.8 ml/kg and 492.1 ml/kg. In the BPD group, the cut-off values of fluid intake on day1, 2, 3, 4 and the first 4 days were 95.3 ml/kg, 112.1 ml/kg, 123.4 ml/kg, 141.4 ml/kg and 476.2 ml/kg. In the BIPI group, the cut-off values of fluid intake on days 1, 2, 3 and 4 and the first four days were 88.6 ml/kg, 95.4 ml/kg, 120.0 ml/kg and 128.6 ml/kg and 430.9 ml/kg. The cut-off values of fluid intake in the hsPDA group were 98.7 ml/kg, 102.7 ml/kg, 124.0 ml/kg, 140.8 ml/kg and 496.5 ml/kg on days 1, 2, 3 and 4 and the first four days, respectively. The ROC curve showed that the cut-off value of fluid intake on the second and fourth day in the BPD group was 0.87 and 0.86, respectively, with the best reference significance. Conclusions High fluid load in preterm infants with very low and extremely low birth weight may increase the risk of BPD, NEC, BIPI and hsPDA.