Women in long-term relationships may experience a decrease in sexual desire.
Female sexual functioning is influenced by many factors, from a woman's mental well-being to age, time, and relationship quality.
Studies show that sexual dysfunction is common among women, with approximately 40 million American women reporting sexual disorders.
A large study of American adults between the ages 18-59 suggests that women are more likely to experience sexual dysfunction than men, with a 43 percent and 31 percent likelihood, respectively.
Treatment options for sexual dysfunction in women have been shown to vary in effectiveness, and the causes of female sexual dysfunction still seem to be poorly understood.
New research sheds light on the temporal stability of female sexual functioning by looking at the relationship between various female sexual functions and relationship status over a long period of time.
Studying the link between relationship status and female sexual desire
Previous studies that examined sexual functions in women did not look at temporal stability and possible interactions between different female sexual functions.
But researchers from the University of Turku and Åbo Akademi University - both in Finland - looked at the evolution of female sexual desire over a period of 7 years.
The new study was led by Ph.D. candidate in psychology Annika Gunst, from the University of Turku, and the results were published in the Psychological Medicine science journal.
Researchers examined 2,173 premenopausal Finnish women from two large-scale data collections, one in 2006 and the other 7 years later, in 2013.
Scientists used the Female Sexual Function Index - a short questionnaire that measures specific areas of sexual functioning in women, such as sexual arousal, orgasm, sexual satisfaction, and the presence of pain during intercourse.
Researchers took into consideration the possible effects of age and relationship duration.
The average age of the participants at the first data collection was 25.5 years. Given that the mean age was quite low and the average age of menopause is much later, at 51 years, the researchers did not think it necessary to account for the possible effects of hormonal changes.
Relationship status influences sexual desire over time
Of the functions examined, women's ability to orgasm was the most stable over the 7-year period, while sexual satisfaction was the most variable.
The ability to have an orgasm improved across all groups during the study, with single women experiencing the greatest improvement.
Women with a new partner had a slightly lower improvement in orgasmic ability than single women, but a higher improvement than women who had been in the same relationship over the 7-year period.
The study found that women who had stayed in the same monogamous relationship over the entire 7-year observation period experienced the greatest decrease in sexual desire.
By contrast, women who had found a new partner over the study duration experienced lower decreases in sexual desire.
Women who were single at the end of the observation period reported stable sexual desire.
According to the researchers, relationship-specific factors or partner-specific factors that have no connection with the duration of the relationship do have an impact on women's sexual functions. Consequently, healthcare professionals should account for partner-specific factors when they treat sexual dysfunction in women.
However, researchers also point out that sexual function needs to be further examined in a short-term study to have a better understanding of the diversity in sexual function variation.
Strengths and limitations of the study
Researchers point out the methodological strengths of the study, as well as its limitations.
Firstly, because the study was longitudinal, it reduced the so-called recall bias, meaning that participants reported their own experience with higher accuracy.
The study also benefited from a large study sample, validated measures, and structural equation modeling, which reduces errors in measurement.
However, the authors note that the long 7-year timeframe may not account for short-term fluctuations, and varying sexual functions may interact differently when studied over a long period of time.
The study did not examine sexual dysfunctions.
Finally, the authors mention that they did not have access to data about cohabitation, or about the duration of singlehood.