Research has shown that premature births rose by 16 per cent in 25 years but survival rates have improved dramatically.
A University study found that the risk of neonatal death from premature birth more than halved.
There was also a 10 per cent reduction in stillbirth associated with pre-term births.
University researchers analysed data relating to nearly 90,000 births in Scotland between 1980 and 2005.
The study will help better understand the trends and causes behind premature births to inform better treatments for expectant mothers.
The number of babies born prematurely increased from 54 per 1,000 births between 1980 and 1985 to 63 per 1,000 births between 2000 and 2005.
The increase in survival rates for babies who are born prematurely backs up decisions by doctors to medically induce births to prevent potential complications.
Improvements in survival rates of premature babies were greater for medically induced or pre-planned Caesarean section births than when labour occurred naturally.
The findings support the shift towards more medically induced early births.
Medically induced preterm deliveries increased by more than 40 per cent.
This compares with a 10 per cent increase in early births from natural onset of labour.
Researchers found the growing number of expectant mothers with diabetes had resulted in an increase in the numbers of babies born prematurely.
They found a seven-fold increase in premature births where the mothers were diabetic before becoming pregnant.
Premature births linked to gestational diabetes, where expectant mothers develop diabetes during pregnancy, also increased four-fold over the study period.
High blood pressure in expectant mothers, however, remained the major factor linked to pre-term births.
However, the proportion of babies born prematurely as a result of this condition decreased over the 25-year study period.
The increase in diabetes as a factor in premature births is also interesting and may be because there are more women with pre-existing diabetes – which is linked to obesity – as well as better diagnosis of expectant mothers with gestational diabetes.
The study was published in the journal PLoS Medicine.
It was carried out in collaboration with Information Services Division and NHS Scotland and funded by the Chief Scientist Office, Scottish Government and the charity Tommy’s.
Premature births are linked to more than 66 per cent of single baby still births, 65 per cent of single baby neonatal deaths and 67 per cent of infants who have a prolonged stay in the neonatal unit.
Photo credit: Tommy's.