BABIES born late are at a "small but significantly increased" risk of being stillborn, according to a major new study covering more than 15 million pregnancies.

Researchers from Queen Mary University of London found that the risk of stillbirth increased for each week that a pregnancy continues past term - defined as 37 weeks gestation.

They also found that there was a "small but significantly increased risk of stillbirth" among mothers whose pregnancy continued until 41 weeks, compared to those who delivered at 40 weeks.

However they stressed that this was still low - accounting for one additional stillbirth for every 1,449 pregnancies.

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The study also highlighted an increase risk of stillbirth among black mothers.

Compared to white women, black women at term were also found to be 1.5 to 2 times more likely to suffer stillbirth at all gestational ages.

Lead researcher Professor Shakila Thangaratinam said: “While there is an additional risk of stillbirth at 41 weeks, compared to 40 weeks, it is small.

"Women who prefer not to have medical interventions such as induction of labour may therefore acknowledge this small additional risk, and choose to wait until 41 weeks so that they have more time to go into labour naturally.

"Meanwhile, other women may prefer to have discussions with their healthcare providers on induction after 40 weeks.

"So this is all about helping women make informed decisions on timing of delivery.”

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More than 3,000 babies are stillborn every year in the UK. In 2017/18 - the most recent year for which figures are available - there were 222 recorded stillbirths in Scotland.

Around a third of stillbirths occur in babies born at 37 weeks or later who were considered to be healthy prior to their death.

Due to evidence of an increased risk of stillbirth beyond 41 weeks, women are routinely offered an induction at this point to bring on labour.

However, today's study - published in the journal PLOS Medicine - is the largest to date to examine the risk of stillbirth between 37 and 41 weeks.

The findings are based on a total of 15,124,027 pregnancies, including 17,830 stillbirths and 2,348 newborn deaths.

These were drawn from 13 existing studies carried out in the UK, US, Denmark and Norway.

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The researchers also analysed the data to assess the risk of infants dying within 28 days of birth depending on gestation.

They found no difference in neonatal death rates among babies born at 37 to 41 weeks.

However, neonatal deaths were 87 per cent more common among babies born at 42 weeks compared to 41 weeks.

Professor Thangaratinam added: “This is the largest study of its kind, and finally provides precise estimates of potential risks of stillbirth. Now that we understand the extent to which stillbirth risks increase with each week of pregnancy, we should be incorporating this information in all discussions around delivery plans in pregnant women at term.

“We were surprised to see how much poorer pregnancy outcomes were for black women – they were up to twice more likely to experience stillbirth than white women. Healthcare professionals need to take these added risks into account when developing care plans for these women.”