One in every eight women and one in every ten men have experienced infertility at some stage in their lives, according to a UK study.

Infertility was defined as having spent more than one year trying unsuccessfully to conceive. 

Among participants in the 16-74 age bracket, the number was lowest among youngest women and peaked among those aged 35 – 44 years. The infertility rate within the women aged 35-44 was almost 18 per cent.

Women and men with higher education and occupational status, and those who had settled later with a partner were more likely to have experienced infertility.

The odds of infertility were also significantly higher among women who first gave birth at age 35 or older, compared to those who had a child before the age 25.

Almost half of the participants who had experienced trouble conceiving a child did not seek medical help for the issue. The women who had their first child at an older age were more likely to seek help for fertility, the study shows.

"Our finding of inequalities in help seeking between those who are better educated and in higher status jobs is (perhaps) not surprising given evidence of unequal distribution of wealth and power and the associated differential access to health care," lead author Jessica Datta of the London School of Hygiene and Tropical Medicine told Reuters.

Infertility was linked to symptoms of depression and dissatisfaction with sex life, the study shows. However, the researchers note that it is not sure whether depression or sexual dissatisfaction was related to the use of fertility treatments.

Couples wishing for a child need not worry, as most couples will conceive eventually, according to Datta. However, she recommends that anyone having fertility concerns consult their general practitioner. 

“It is generally accepted that over 80 per cent of couples in the general population will conceive within one year if the woman is aged under 40 years and they do not use contraception and have regular sexual intercourse," said professor Ann Berrington of the University of Southampton, who was not part of the new research.

"Of those who do not conceive in the first year, about half will do so in the second year," for a cumulative pregnancy rate over 90 per cent, she said.

There was no significant association between women’s experience of infertility and whether they were happy in their current relationship or not.

The study was conducted by surveying more than 15,000 women and men aged 16 – 74 years.