Survival rates for extremely premature babies have been constantly increasing in Sweden. Between 1973 and 1979, 46 surviving children were registered who were born before the 28th week of pregnancy. Now over 1 000 children survive over a corresponding period and four out of five extremely premature babies today reach the age of one.

But what happens then? New findings suggest that premature babies form a risk group for developing high blood pressure, cardiovascular disease and lung problems at an earlier age than other children and adults. Almost all extremely premature babies need ventilator treatment as newborns for acute lung disease. Many children present persistent lung problems for months, some for the whole of their first year. Sixty per cent also have problems with the cardiovascular system that require medical or surgical treatment. The further development of heart and lung function in these children is largely unknown.

The EXPRESS study offers a unique opportunity to map the long-term cardiovascular and respiratory health of these children. The detailed data that has been gathered on all surviving children enables a continued follow-up with very good knowledge of early background factors. A detailed survey of the significance of early nutrition and growth for the cardiovascular and respiratory systems is also underway. In the CHARM study, the children who participated in the EXPRESS study are invited to participate at the age of six and a half in a detailed survey of blood pressure, cardiovascular and respiratory function, and physical activity.

The number of children who were born extremely prematurely is growing rapidly and they now total several thousand. The first generation of survivors are now young adults. It is high time to find out how important organs such as the cardiovascular and respiratory systems develop and function after the neonatal period and during childhood in order to improve neonatal care, prevent and diagnose chronic health problems, and evaluate the need for further support and interventions.

Data collection for EXPRESS CHARM is currently underway in three regions: Stockholm, Umeå and Skåne. The data collection is expected to be completed in 2013 and the first results of the study will be presented in 2014. The researchers in charge of the study are Professor Mikael Norman, Karolinska University Hospital, Reader Magnus Domellöf, Norrland University Hospital and Professor Vineta Fellman, Skåne University Hospital.