Published: 30-04-2013 00:00 | Updated: 30-10-2014 10:18

Better than expected prognosis for extremely preterm infants

Every year in Sweden more than 250 babies are born over 14 weeks prematurely. Although the survival rate has improved in recent years, knowledge of the neurological and physical development of these infants is incomplete. A study published in the scientific periodical JAMA now shows that three out of four extremely preterm babies were normally developed or had mild disabilities by the age of 30 months.

The study is part of EXPRESS, a joint project involving researchers from several collaborating universities, including Karolinska Institutet. Internationally speaking, EXPRESS is one of the largest and most detailed follow-up studies of extremely preterm infants.

In the present study, 456 surviving extremely preterm babies were followed up at the age of 30 months and compared to babies born full-term in terms of cognition, language, motor function, cerebral palsy (CP), and visual/auditory function. One important point of inquiry was whether the higher survival rate has been achieved at the cost of increasing numbers of disabled children.

The results show that the majority (73 per cent) of the extremely preterm babies had only slight disabilities, if any. 42 per cent had no disability at all, compared to 78 per cent of the full-term group, while 31 per cent had only slight disabilities, compared to 19 per cent of the full-term group. Furthermore, there was a relatively low incidence of cerebral palsy (CP) in extremely preterm infants (seven per cent) and only six of the babies had CP severe enough to probably confine them to a wheelchair.

The researchers believe that the positive development can be traced to the regional centralisation of the peri and neonatal care of babies born extremely prematurely and to effective collaboration between the regional and county hospitals and between obstetricians and paediatricians.

"The families' involvement in the care process and the high proportion of babies that were breast-fed during early infancy are probably also contributing factors," says the study's lead author, Professor Fredrik Serenius of Uppsala University.

The EXPRESS (Extremely Preterm Infant Study in Sweden) study is a national programme involving obstetricians, paediatricians, eye doctors and psychologists at medical and social science faculties and university hospitals in Sweden. It was set up to better understand long and short-term prognoses and is led by Professor Karel Maraál in Lund. The institutions that participated in this present study were the universities of Uppsala, Lund, Gothenburg, Umeå, Linköping and Örebro and Karolinska Institutet. It was financed with grants from a number of bodies, including the Swedish Research Council, the Lilla Barnet fund, the EU's Seventh Framework Programme and several county and regional authorities in Sweden through agreements with the respective universities.


Neurodevelopmental outcome in extremely preterm infants at 2.5 years after active perinatal care in Sweden.
Serenius F, Källén K, Blennow M, Ewald U, Fellman V, Holmström G, et al
JAMA 2013 May;309(17):1810-20