Women experience a notable decline in sexual function approximately 20 months before and one year after their last menstrual period, and that decrease continues, though at a somewhat slower rate, over the following five years, according to a study led by a researcher at Wake Forest Baptist Medical Center.

The study, published ahead of print in the online issue of Menopause: The Journal of the North American Menopause Society, also found that various factors that frequently co-occur with menopause have less direct influence on declining sexual function than menopause itself.

"Sexual functioning in women declines with age, and there has been much debate about how much this is due to menopause, aging or other physical, psychological or social factors," said the study's lead author, Nancy Avis, Ph.D., professor of public health sciences at Wake Forest School of Medicine, part of Wake Forest Baptist. "Our findings support that menopause has a negative effect on sexual functioning in many women."

Additionally, the study found that women who have a hysterectomy before the onset of menopause do not experience a marked decline in sexual function immediately before undergoing the procedure but do so afterward, for as long as five years.

The researchers based their findings on information collected from 1,390 participants in the federally funded Study of Women's Health Across the Nation (SWAN), which began in 1996. These women, who were between the ages of 42 and 52 at the time of enrollment in the study and who had a known date of final menstrual period during their participation, responded to questionnaires dealing with various aspects of sexual function - including desire, arousal, satisfaction and pain - between one and seven times over the course of the study. The researchers analyzed 5,798 of these self-assessments (4,932 from the 1,164 women in the natural menopause group and 866 from the 226 women in the hysterectomy group) and tracked the changes in the respondents' scores on the sexual-function questionnaires relative to either their final menstrual period among women who experienced a natural menopause or the hysterectomy.

Of note, in the natural menopause group the researchers found that race/ethnicity played a major role in the decline of sexual function, with African-American women experiencing a significantly smaller decline and women of Japanese descent experiencing a much greater decline when compared with white women.

"Sexual functioning is an important component of women's lives. More than 75 percent of the middle-aged women in the SWAN study reported that sex was moderately to extremely important to them when the study began," Avis said. "It is important for women and their health care providers to understand all the factors that may impact women's experience of sex in relation to both the natural menopausal transition and hysterectomy, and we hope our findings will contribute to better understanding in this area."

The SWAN project received funding from the National Institutes of Health through the National Institute on Aging, National Institute of Nursing Research and NIH Office on Women's Health in grants U01NR004061, U01AG012505, U01AG012535, U01AG012531, U01AG012539, U01AG012546, U01AG012553, U01AG012554 and U01AG012495.

Article: Change in sexual functioning over the menopausal transition: results from the Study of Women's Health Across the Nation, Avis, Nancy E. PhD; Colvin, Alicia PhD; Karlamangla, Arun S. MD, PhD; Crawford, Sybil PhD; Hess, Rachel MD; Waetjen, L. Elaine MD; Brooks, Maria PhD; Tepper, Ping G. PhD; Greendale, Gail A. MD, Menopause: The Journal of the North American Menopause Society, doi: 10.1097/GME.0000000000000770, published 31 October 2016.