Women who are in a long-term relationship are more likely to experience a decrease in sexual desire, scientists have said. Changes in relationship status were found to affect several different sexual functions, but a libido decline after spending years with the same person was the most pronounced trend overall.

Past studies that have investigated female sexual function have rarely focused on how it evolves over time or how different sexual functions interact between one another.

This is why new research published in Psychological Medicine looks at women's sexual functions – including desire, sexual satisfaction and orgasm – over a period of seven years, and takes into account what kind of relationships these women were in.

Data from 2,173 Finnish women from two large-scale, population-based data registers was collected for the study, seven years apart. The scientists used the female sexual function index, a questionnaire used to assess domains of sexual function in women in clinical trials. Effects of age and relationship duration were taken into account in the statistical analysis.

Boosting sexual desire

The researchers discovered that most aspects of women's sexual functions appeared unstable over the years. Previous sexual function was not a good predictor of future sexual function overall, with satisfaction, pain and arousal changing over time. Sexual satisfaction in particular varied greatly in seven years, but the ability to have an orgasm remained stable for most women – suggesting that sexual satisfaction and orgasm are not always linked.

When it came to boosting women's desire, other sexual functions such as their ability to have an orgasm only had a small impact, but the scientists found out that relationship length and status was perhaps more relevant.

Indeed, women who stayed in the same monogamous relationship from the beginning to the end of the study reported the greatest decrease in their sex drive. Women who had started a new relationship during the course of the study also experienced reduced libido, but to a smaller degree. Finally, women who were single at the end of the observation period reported stable sexual desire.

More studies are needed to better make sense of the variations in female sexual function over time. However, the researchers already say it would be useful to take into account partner-specific factors and relationship characteristics in the treatment of women's sexual dysfunctions.

"Our results advocate tailored psycho-behavioural treatment interventions for female sexual dysfunctions that take partner-specific factors into account", they conclude.