Tommy's says there are a number of risk factors which may lead to premature birth including maternal smoking, infections in the womb, twin or triplet pregnancies. Being a teenage or older mother is also linked to increased risk, as is being underweight.
Babies can also be delivered prematurely if doctors decide the health of the mother or baby is at risk, perhaps because the mother has developed pre-eclampsia or if the baby is abnormally small.
Dr Rebecca Jones, from Tommy's Manchester Research Centre at St Mary's General Hospital, said: "It is hard to tell from the figures whether the increase is due to spontaneous births, when the woman goes into labour early, or whether it is due to medically-induced premature delivery. Potential reasons for the increase may be more mothers having babies at a young or late age, more multiple pregnancies because of IVF, changes in smoking rates, or changes in the general health of the population."
Ronald Lamont, a spokesman for the Royal College of Obstetricians and Gynaecologists, said there had been disparities in how different hospitals recorded premature births, and it was possible this had changed.
"If a baby is born at 36 weeks and six days, some will round that up to 37 weeks, when they should round it down to 36. Another reason is that now neonatal doctors can keep more babies born very early alive, so obstetricians like me can deliver them. And if there is a problem with the pregnancy, doctors do have the option to deliver babies safely."
November 2008 |
