A top children's doctor has warned "common assumption" was denying some babies with heart disease and feeding problems the tailored care they needed when in hospital.
Dr Nadeem Afzal, based at Southampton Children's Hospital, said a long-held belief babies born with the most severe forms of heart disease were more likely to have feeding and growth difficulties meant others were often overlooked.
He spoke out after completing research which showed that, although more than two-thirds of children (67%) with heart disease had feeding or growth problems, it was not related to the complexity of their condition.
"For too long there has been little information widely available on feeding and growth issues in relation to children with heart disease and this has led to the common clinical assumption that the most complex cases are the most likely to require nutritional input," said Dr Afzal, a consultant paediatric gastroenterologist.
"This has presented us with a situation where those with less severe heart conditions are not assessed on a level playing field and means they could be missing out on the additional support they require."
The study looked at 60 children under a year old who were admitted to Southampton General Hospital with a cardiac diagnosis - ranging from mild or moderate to severe - over the period of two years.
The research team found no correlation between problems such as low weight, frequent stools, the need for nasogastric tube feeding or reflux and the complexity of heart disease, with more than half (56%) of babies with mild or moderate congenital heart disease requiring nutritional support.
Dr Afzal said: "Nutrition in the first year of life has a big impact on a child's growth and development in infancy and through childhood in general, but in children with heart problems it can also affect treatment and can make a big difference in the speed and effectiveness of recovery from surgery.
"The right decisions from a gastrointestinal viewpoint play an important part in the overall health of the child and their future years, which make this vulnerable group of patients a particular priority."
He said the project, presented to members of the European Society of Paediatric Gastroenterology, Hepatology and Nutrition, not only demonstrated the need for dedicated patient-specific planning, but also the importance of combined expertise to provide a complete service.
He added: "What this project shows us is that patient management needs to be tailored to children according to individual needs in all instances, while experts in other fields, such as gastroenterology, are not always required just for the most serious cases but for varying levels of severity."