Children born through fertility treatments are 33 percent more likely to develop psychiatric problems than those conceived through natural births, according to a University of Copenhagen study.

Researchers said that autism or schizophrenia problems are not developed due to fertility procedures, but mothers who find it difficult to get pregnant are in fact passing down the genes.

Researcher Dr Allan Jensen said that fertility doctors need to be aware of these small consequences among children born to women who had fertility problems. However, this knowledge "should always be balanced against the physical and psychological benefits of a pregnancy."

For the study, researchers compared mental disorders in children conceived naturally and those born to mothers who had undergone fertility treatments like IVF. Overall 2,430,826 children, born between 1969 and 2006, in Denmark were involved in the study. Among these children, five percent of them were born to women with registered fertility problems.

Researchers found that 170,240 children were admitted to hospital for a psychiatric disorder. But, children born to mothers with fertility problems faced a 33 percent heightened risk of developing psychiatric disorders.

They said that children conceived through fertility procedures are also more likely to suffer from psychoses, affective disorders, anxiety and other neurotic disorders, mental and behavioural syndromes including eating disorders, autism and attention deficit hyperactivity disorder.

The study also found that 1.9 per cent of all diagnosed psychiatric disorders in Denmark are linked to mother's infertility.

"In my opinion this figure supports our interpretation of the results - that the increased risk is real but modest," Jensen said in a press release.