Little progress has been made in improving the long-term health of extremely premature babies, and with pre-term births on the rise across Europe, rates of serious disability are likely to increase, doctors said on Wednesday.
A decade of advances in medicine mean more babies born at between 22 and 26 weeks gestation manage to survive, but rates of severe health complications remain as high as they were in 1995, according to research by neonatal specialists in Britain.
The findings of two separate studies published in the British Medical Journal suggest the number of children and adults with disabilities caused by premature birth will rise in coming years.
Babies born before 27 weeks of gestation - 13 weeks before they would be considered full term - face a battle for survival. Many of those who do survive face problems such as lung conditions, learning difficulties and cerebral palsy.
Rates of premature birth are rising in many European countries and are particularly high in Britain and the United States.
"As the number of children that survive pre-term birth continues to rise, so will the number who experience disability throughout their lives," said Neil Marlow, of University College London's Institute for Women's Health, who worked on both studies and presented the results at a briefing in London.
He said this was "likely to have an impact on the demand for health, education and social care services."
The two studies, led by Marlow and Kate Costeloe of Queen Mary, University of London, compared a group of babies born in the UK between 22 and 26 weeks' gestation in 2006 with those born between 22 and 25 weeks over a 10-month period in 1995.
The first one looked at the immediate survival rates and the health - until they went home from hospital - of extremely premature babies born in 2006 and compared them with 1995 rates.
Researchers found the number of babies born at 22 to 25 weeks and admitted to intensive care increased by 44 percent during this period. The number of babies who survived long enough to go home from hospital increased by 13 percent.
There was no significant increase in survival of babies born before 24 weeks - the current legal limit for abortion in Britain - and the number of babies who had major health complications was unchanged over the decade.
Costeloe said what while survival rates for babies born at less than 27 weeks gestation were moving in the "right direction", there was still room for improvement.
"We can't be complacent, because the fact of the matter is, that in 2006 if at this gestation you were alive at the end of the first week, you had no greater chance of going home (from hospital) than you would have done had you managed to survive the first week of life in 1995."
The second study looked at the health of the 2006 babies when at three years old and compared this with 1995. It found that while 11 percent more babies survived to three without disabilities the proportion of survivors born between 22 and 25 weeks with severe disability was about the same - at 18 percent in 1995 and 19 percent in 2006.
The researchers also found a link between gestational age and the risk of disability, with babies born earlier more likely to have serious health complications at three years of age.