Babies born through IVF are up to twice as likely to suffer potentially deadly heart defects, a major study has found.
Those conceived through assisted reproductive technology such as in vitro fertilisation (IVF) have a significantly higher chance of congenital heart issues.
This risk rises further if they were born a twin, research involving more than 7.7 million people found.
Experts said the discovery could help clinicians make faster diagnoses, with babies often requiring immediate surgery.
Researchers studied health records of all liveborn children born in Denmark, Finland, Norway and Sweden over a period spanning between 20 and 31 years.
Babies born through IVF are up to twice as likely to suffer potentially deadly heart defects, a major study has found
Those conceived through assisted reproductive technology such as in vitro fertilisation (IVF, pictured close-up) have a significantly higher chance of congenital heart issues
They compared data on babies born following assisted reproduction, including IVF, intracytoplasmic sperm injection (ICSI) and embryo freezing, with data on babies conceived naturally.
They assessed how many liveborn children in each group were diagnosed with a major heart defect or with a serious heart defect either in the womb or in the first year of life.
Factors such as child’s year of birth, country of birth, mother’s age at delivery, if the mother smoked during pregnancy, or if the mother had diabetes or heart defects were taken into account.
Heart defects were around 36 per cent more common in babies born after assisted reproduction, compared to babies naturally conceived, with the risk similar regardless of the type used.
Twins or other multiple birth babies were more than twice as likely to have a major heart defect than the rest of the population, at 2.47 and 1.15 per cent, respectively.
Scientists said the findings, published in the peer-reviewed journal Heart, may indicate that there is some common factor underlying infertility in parents and congenital heart disease in their babies.
Heart defects were around 36 per cent more common in babies born after assisted reproduction, compared to babies naturally conceived
Professor Ulla-Britt Wennerholm, of the University of Gothenburg in Sweden, said: ‘Congenital heart defects can be extremely serious requiring specialist surgery when babies are very young, so knowing which babies are at the greatest risk can help us diagnose heart defects as early as possible and ensure the right care and treatment are given.
‘More and more people are conceiving with the help of assisted reproductive technology, so we might expect to see increases in cases of congenital heart defects worldwide.’
Almost 400,000 have been born in the UK using IVF since 1991, according to the Human Fertilisation and Embryology Authority.
Scientists said it was important couples undertaking the procedure were aware of the potential risks, such as other birth defects or lower birth rate.
In an accompanying editorial, Dr Nathalie Auger, from University of Montreal Hospital Research Centre in Canada, said: ‘While most neonates born after assisted reproductive technology are healthy, these procedures are not without risks.
She added: ‘Patients who use assisted reproductive technology tend to differ from the general population.
‘These patients may have underlying morbidities that affect both fertility and the risk of heart defects.’
