It has long been dismissed as an old wives’ tale that morning sickness signals a healthy pregnancy.
But experts now say it is probably true – giving encouragement to sufferers, who famously include the Duchess of Cambridge.
More than four in five women battle nausea in the first 12 weeks of pregnancy, and around half experience vomiting.
Scientists at the University of Reading say the sickness may be a good thing as it is caused by a hormone vital for a healthy pregnancy.
It has long been dismissed as an old wives’ tale that morning sickness signals a healthy pregnancy – but experts now say it is probably true (stock image)
Endokinin, which acts on the brain to cause morning sickness, also ensures good blood flow through the placenta so that oxygen and nutrients can reach the unborn baby.
Professor Philip Lowry, from the University of Reading’s school of biological sciences, said he hoped the news would bring ‘psychological relief’ to pregnant women.
‘There may be a temptation to use endokinin-blocking drugs to treat morning sickness during pregnancy, but these findings suggest that such drugs could affect the health of the pregnancy and must be avoided,’ he said.
Awful as morning sickness can be, it does not endanger babies and usually clears up by weeks 16 to 20 of a woman’s pregnancy.
However some women, such as the Duchess of Cambridge, suffer a more severe form of nausea and vomiting, hyperemesis gravidarum, which can see them admitted to hospital and given fluids through a drip.
Kate developed acute morning sickness weeks into her current pregnancy, having been hospitalised when she was expecting Prince George and suffering again with Princess Charlotte.
The news will give encouragement to sufferers, who famously include the Duchess of Cambridge.
The expert review, led by Professor Lowry, states: ‘Although morning sickness is very unpleasant, the “old wives’ tale” that it results in a healthy baby now has a credible scientific explanation.’
The body releases endokinin, which improves blood flow in the placenta, to ensure the baby is not starved of nutrients.
However, its entry into the bloodstream stimulates receptors in the brain known to cause nausea and vomiting.
The review, published in the Journal of Molecular Endocrinology, references a study of 800 pregnant women from last year. It found that, for those with a history of miscarriage, vomiting and nausea in subsequent pregnancies was linked to higher odds of a successful birth.
Doctors advise women with morning sickness to get lots of rest, drink plenty of fluids and eat small, frequent meals high in carbohydrates.
Death risk for mums-to-be who stop taking medication
Women are dying because they stop taking medication during pregnancy, a major audit has found.
Scares over the impact of drugs on unborn babies mean many mothers-to-be stop taking vital treatments as soon as they become pregnant.
The national maternity audit, compiled by researchers at Oxford University, examined 124 women who died and 46 who fell ill in the UK and Ireland between 2013 and 2015. It raised particular concerns about women with epilepsy who had uncontrolled seizures when they stopped taking their drugs and women with mental health problems who decided to stop medication.
Scientists have previously warned that most pregnant women needlessly avoid common medicines for fear of harming their unborn baby. Thousands believe even mild treatments – such as antibiotics or paracetamol – could be harmful.
But women are also avoiding medication for life-threatening conditions, the report reveals, The team identified nine epileptic women who died suddenly during pregnancy or shortly after giving birth. All either decided to stop taking the drugs or were told to by their GP.
Studies have raised concerns about the impact of epilepsy drugs on unborn children. But experts say the risk of seizures can be managed with expert help.
Professor Marian Knight, who led the research, said: ‘I cannot over-emphasise the importance of seeking specialist advice before women stop or change their medicines in early pregnancy.’