Researchers from Murdoch Children's Research Institute and Perth’s Telethon Kids Institute used unique data sets from Western Australia to follow more than 700 thousand children born between 1980 and 2010 until they were 18.
The study published today in the Lancet Infectious Diseases found children were 12 per cent more likely to be hospitalised with an infection for each week they were born before 39 to 40 weeks, 19 per cent more likely to be hospitalised for each 500g reduction in birth weight below 3 to 3.5kg, and 41 per cent for each 5cm reduction in birth length from 45 to 50cm.
The risk was significantly increased even for those born late preterm or early term, or with a near-normal birth weight or birth length.
The study’s lead author Professor David Burgner, from Murdoch Children's, said hospital admissions were highest for children born at less than 28 weeks and the increased risk persisted until the child was 18.
“Our study shows that the health implications of being born even slightly premature and underweight can last throughout childhood,” Professor Burgner said.
“Although we’ve known that extremely premature children have greater risk of infection as babies, the increased risk in those born towards term or near-normal birth weight has not been well recognised, nor the fact that it persists until adolescence.”
“It’s therefore important that we develop interventions to prolong pregnancy and optimise growth within the womb, to reduce the risk of premature birth and low birth weight.”
“We also need to better monitor children at risk in order to prevent severe infections in this group.”
Professor Nick de Klerk from the Telethon Kids Institute said this was the most comprehensive analysis to date of the effect of gestational age, birthweight, and birth length on infectious disease morbidity in childhood and adolescence.
“The results are of particular relevance to low-income and middle-income countries, where around 43.3 million infants are born preterm, of low birthweight, or small for their gestational age,” Professor de Klerk said.