In preterm infants, does fluid restriction, as opposed to liberal fluid prescription, reduce the risk of important morbidities and mortality?

Aim To answer the clinical question: 'In preterm infants, does fluid restriction, as opposed to liberal fluid prescription, reduce the risk of important morbidities (namely, intraventricular haemorrhage, necrotising enterocolitis, bronchopulmonary dysplasia and patent ductus arteriosus) and mortality?' Methods Literature searches were conducted of Medline, Embase and Cochrane Library. Results were limited to human clinical trials on infants and those published in English. The reference lists of relevant articles were screened for further articles. Studies that examined measures which inform diagnostic criteria of morbidities of interest (such as echocardiographic changes) but did not go further to confirm or exclude presence of said morbidities in study populations were excluded. Results A total of 110 articles were found and screened by title and abstract. The final analysis included five randomised controlled trials and five case control studies. Among the randomised controlled trials, there is some suggestion (though not unanimous) that liberal fluid regimens are associated with an increased risk of patent ductus arteriosus, necrotising enterocolitis and mortality. Case control studies focused on patent ductus arteriosus and bronchopulmonary dysplasia or chronic lung disease, with all but one study suggesting an increased risk of these complications with liberal fluid regimens. Conclusion Further investigation is needed to clarify the optimal fluid regimen for preterm infants to ensure adequate hydration and nutrition without contributing to serious complications.