Researchers also found the risk of ending up in hospital for other serious psychiatric disorders including schizophrenia was markedly higher in women unable to become pregnant due to infertility.
The academics behind the study, presented at the annual conference of the European Society for Human Reproduction and Embryology (ESHRE) in Istanbul, said their results were “only the tip off the iceberg” because many more would be affected, but not so badly as to need in-patient treatment.
British fertility specialists argued the results were “shocking” evidence that infertility should be classed as a disease.
They said it added weight to the argument that IVF should receive greater public funding, because infertility was a disease in its own right.
Birgitte (corr) Baldur-Felskov and colleagues at the Danish Cancer Society Research Centre looked for hospitalisations for mental health problems in almost 100,000 women who had previously seen a specialist about infertility. They compared two groups: those who went on to have a child and those who did not.
In women who remained childless, the risk of being hospitalised for alcoholism or substance abuse was 103 per cent higher – or just over twice as high – as it was in women who managed to get pregnant after seeing an infertility specialist.
Their risk of being hospitalised for schizophrenia was 47 per cent higher, as was their chance of ending up in a ward due to an eating disorder, although the latter finding was not statistically significant.
She said of their results: “This is only the tip of the iceberg. We were only able to analyse the risk of severe psychiatric disorders resulting in hospitalisation.”
There would be many other women who were affected but treated as outpatients, and perhaps even more not treated at all, she explained.
Dr Baldur-Felskov also said the results suggested that the psychological impact of unwanted childlessness was not just a transient phase.
This was because the risks were equally strong more than a decade after women had seen a fertility specialist, as they were in the years immediately following their attempts to get pregnant.
She said women should be made aware of the increased risk of psychiatric disorders after having unsuccessful fertility treatment.
The group did find, however, that women who failed to give birth were at a 10 per cent lower risk of ending up in hospital for depression than those who became mothers.
Dr Allan Pacey, chairman of the British Fertility Society, said: “I was aware that women who were unable to have children were not happy and had difficulty with their ongoing lives, but these results are really shocking.”
He said the study showed that infertility was “more than just wanting to have a baby”.
He added: “I think it illustrates my personal frustration with all those people who say infertility isn’t a disease and it shouldn’t be funded because having a baby is a lifestyle choice.”