Women who do not conceive following fertility treatment have poorer mental health in the long run if they are unable to let go of their desire to have a child, a study has found.

Welsh and Dutch researchers looked at over 7,100 women who had undergone fertility treatment in 12 different hospitals between 1995 and 2000. The women were then followed up in 2011 and 2012. Most had completed their last fertility treatment 11-17 years previously.

All were asked a wide range of questions about their personal lives and their fertility problems. They were also asked whether they had gone on to have children and if they had not, whether they still wanted them.

While most of the women had come to terms with their failed fertility treatment, over 400 said they still wanted to have children. The researchers found that the mental health of these women was worse than those who had come to terms with not having children.

"We found that women who still wished to have children were up to 2.8 times more likely to develop clinically significant mental health problems than women who did not sustain a child wish. This link between a sustained wish for children and worse mental health was irrespective of the women's fertility diagnosis and treatment history," noted the study's lead author, Dr Sofia Gameiro, of Cardiff University.

The study found that women had better mental health if the cause of infertility was unknown or due to their male partner, if they started treatment at an older age, if they had a better education, and if they were married or living with their partner rather than single divorced or widowed.

It also found that women who do go on to have a child, but yearn for more children, have poorer mental health than those who never go on to have a child but accept this fact.

"Our study improves our understanding of why childless people have poorer adjustment. It shows that it is more strongly associated with their inability to let go of their desire to have children. It is quite striking to see that women who do have children, but still wish for more children, report poorer mental health than those who have no children but have come to accept it," Dr Gameiro said.

She emphasised that a consultation should always be held with patients after treatment, whether it is successful or not, as this could ‘enable fertility staff to identify patients more likely to have difficulties adjusting to the long-term, by assessing the women's possibilities to come to terms with their unfulfilled child-wish'.

"These patients could be advised to seek additional support from mental health professionals and patient support networks," she said.

Meanwhile, the researchers pointed out that it is not known why some women are able to come to terms with not having children after failed fertility treatment, while others are not.

"Psychological theories would claim that how important the goal is for the person would be a relevant factor. The availability of other meaningful life goals is another relevant factor. It is easier to let go of a child-wish if women find other things in life that are fulfilling, like a career," Dr Gameiro added.

Details of these findings are published in the journal, Human Reproduction.