Over a third of children born before the seventh month of pregnancy are disabled. According to a new study the degree of disability rises the earlier they are born.
The investigation by French researchers was prompted by the fact that more and more children born prematurely in advanced economies are able to survive, thanks to better-equipped hospitals and better-trained staff.
A team led by Pierre-Yves Ancel and Beatrice Larroque of the National Institute of Health and Medical Research (Inserm) looked at the health of 1,817 five-year-old French children who had been born between 22 and 32 weeks of pregnancy.
They compared this with a 'reference group' of 396 children who had been born at 39-40 weeks of gestation.
The children were all assessed for cognitive skills according to the mental processing composite (MPC) scale, a benchmark that is roughly equivalent to IQ.
They were also checked for hearing or visual problems and for walking with or without an aid.
Among children born very pre-term, five percent had severe disability, nine percent had moderate disability and 25 percent minor disability. Cerebral palsy was diagnosed in nine percent of children in this category.
In the reference group, severe disability was found in 0.3 percent of children, moderate disability in three percent and minor disability among eight percent.
Between 13 and 21 percent of children born at 24-28 weeks had an MPC of 70 or below, compared to only three percent in the reference group, where the MPC averaged more than 106.
Special healthcare resources, such as physiotherapists, speech therapists, neurologists and day-care centres, were used by 42 percent of five-year-olds born at 24-28 weeks and by 31 percent of those born between 29 and 32 weeks.
By comparison, only 16 percent of children born at 39-40 weeks needed this help.
The authors say these figures show how cognitive and neuromotor problems increase as the time of pregnancy decreases.
Preventing such disabilities at the outset, and unlocking better ways to treat children with the disabilities, are essential, they say.
But, they admit, 'These results raise questions about health and provision of rehabilitation services, and the cost of these services to families and society.'
The study said between 1.1 and 1.6 percent of babies in Europe today are born before 33 weeks of gestation. In France, a country of 62 million, almost 10,000 infants are born before 33 weeks, it said.