Pregnant women with low levels of a certain hormone are twice as likely to have numerically-challenged children
If you’ve always struggled with sums, you can now blame your mother.
A hormone deficiency in pregnant women increases the chances of their children being bad at maths, research has shown.
Children of women with low levels of a thyroid hormone are 60 per cent more likely to fare badly in arithmetic when they reach school age than those whose mothers have normal levels, scientists found.
Children born to mothers with low levels of the hormone thyroxine are 60 per cent more likely to be bad at maths than those born to women with normal levels, according to new research (file photo)
Previous studies had already shown that pregnant women lacking the hormone, thyroxine, are at risk of giving birth to children whose mental development is impaired in infancy.
The new findings are the first to indicate how this might affect a child’s performance at school.
Lead author Dr Martijn Finken, from the VU University Medical Centre in the Netherlands, said: ‘Whether these problems persist into adulthood remains to be seen. We will continue to follow these children to answer this next big question.’
Dr Finken’s team measured thyroxine levels in the mothers of 1,196 healthy children when they were 12 weeks pregnant.
After birth, the children’s progress was followed until age five, when test scores for language and arithmetic were recorded.
The study found that five-year-olds whose mothers had the lowest levels of thyroxine at the end of their first three months of pregnancy were almost twice as likely to score ‘subnormal’ marks in the maths test.
When influences of family background and health factors were stripped out of the results, a 60 per cent difference in the test scores remained.
A ‘subnormal’ test score was defined as coming in the bottom half of the class.
In the future, hormone tests could conceivably be used to identify children likely to need extra help in maths at school, said the researchers.
Dr Finken added: ‘It is possible that these children could benefit from hormonal supplements to boost their brain development in the womb. Such treatment has been tried in the past but as yet has failed to improve cognitive ability.’
The latest findings were published in the European Journal of Endocrinology.
In September last year, Dr Finken published preliminary results after following the children.
At the time, he said it may be possible to deal with the deficiency by testing women’s hormones early in pregnancy and giving thyroxine supplements to those who need them.
Women should take the tablets in the first four weeks of pregnancy, he said.
Commenting on Dr Finken’s work last year, British expert Professor John Lazarus explained that during early pregnancy, an unborn baby is not yet able to produce its own thyroxine.
This leaves it dependent on the mother’s supply – but studies suggest that up to two-thirds of mothers-to-be in Britain are low in the hormone.
Professor Lazarus, who is a former trustee of the British Thyroid Foundation, put the widespread problem down to a lack of iodine in the diet.
Iodine, which is found in milk and fish, is the main ingredient of thyroxine.
He suggested that iodine should be added to salt to boost people’s consumption – a move that has been taken in many other countries.
The professor, who is chairman of the UK Iodine Group, advises women to take iodine during pregnancy. However, it is not currently on the list of supplements the NHS recommends for mothers-to-be.
Professor Lazarus said it is safe for pregnant women to take 100 to 150 micrograms a day.
Experts writing in the journal Lancet Diabetes and Endocrinology this month said boosting the iodine levels of pregnant women would boost babies’ brain power and make billions for the economy.
It would save the NHS £200 per woman in health costs, experts say. And when the child’s boost in intelligence is considered – an average 1.22 IQ points – the benefit to society would be £4,500 per child over their lifetime, they said.
Source: Mail Online
