New research shows premature babies are more susceptible to infectious diseases not only once they're born, but right through childhood into their late teens.

The study, published in the Lancet Infectious Diseases journal, followed data sets from 700,000 Western Australian children born between 1980 and 2010.

Murdoch Children's Institute Researcher Professor David Burgner said the risk of serious infectious diseases is heightened throughout childhood.

"The risk of being admitted to hospital with infection, so quite severe infection, is at present not only in the first few weeks of life, but actually the risk is then right until we finished the study when the kids turn 18, so it's quite a long-lasting risk."

Professor Burgner said the study found even babies born only slightly premature had a high risk of contracting an infectious diseases.

He said even babies born close to full term, even up to 38 weeks, still had an increased risk compared to those born at 39, 40 weeks.