A new study from UK has shown that one in three premature babies have lower scores on tests when compared with children born full-term.

Researchers at University of Bristol's School of Clinical Sciences, who conducted the study, also found that at least a third of all preemies in the study had special educational needs (SEN). Children enrolled in school a year earlier due to their premature birth status were at particular risk of suffering from learning disabilities.

Some 15 million babies are born preterm (before 37 weeks) every year, and the numbers are rising, says the World Health Organization. India, Nigeria and the U.S. top the list of countries that have maximum numbers of preterm births.

Preterm babies are at higher risk of learning disabilities, cerebral palsy, problems associated with breathing, vision and hearing loss and digestive problems, according to the National Institutes of Health.

The present study was based on data from 12,000 participants enrolled in Bristol's Children of the 90s study. Researchers found that children sent to school a year earlier due to their birth status had lower scores on Key Stage 1 (KS1) test than full-term children.

"Our research indicates that children who were born prematurely are at higher risk of poor school performance and in greater need of additional educational support at primary school. Some of the social and educational difficulties these children face may be avoidable by recognising the impact that their date of birth has on when they start school," said Dr David Odd, Senior Clinical Lecturer at the University of Bristol's School of Clinical Sciences and lead author of the study, according to a new study.

The study," 'Preterm Birth, Age at School Entry and Educational Performance' is published 17 October 2013, in PLOS ONE.