Sexual dysfunction among women of reproductive age: A systematic review and meta-analysis

Abstract Background Available statistics show a high prevalence of sexual dysfunction (SD) among women worldwide. Various factors affect SD among women of reproductive age. Objective To evaluate studies on the prevalence and determinants of SD in different parts of the world. Materials and Methods MEDLINE, EMBASE, Web of Science, Scopus and ProQuest databases were systematically reviewed during 2000–2019. All original articles were reviewed. The STROBE checklist was used to evaluate the quality of the papers. I2 was calculated to determine heterogeneity. Fixed effects and/or random-effects models were applied to estimate the pooled prevalence. Meta-regression analysis was also performed to identify the sources of heterogeneity. Results Based on the results of the meta-analysis (21 eligible studies), the pooled prevalence with 95% confidence interval of SD was estimated at 50.75% (41.73–59.78). The prevalence of pain and disorders in arousal, sexual desire, lubrication, orgasm, and sexual satisfaction were calculated (39.08%, 48.21%, 50.70%, 37.60%, 40.16%, and 35.02%, respectively). Also, age, depression, low education level, increased duration of the marriage, and the presence of chronic diseases were the highest risk factors for SD. Conclusion The prevalence of SD in women of reproductive age varies in different countries. Considering the importance of female SD, further studies are needed to facilitate the development of relevant educational interventions.


Introduction
Sexual dysfunction (SD) is any dissatisfaction with one's sexual function which leads to distress.
The diagnostic and statistical manual of mental disorders classifies female sexual dysfunction (FSD) as orgasmic, interest/arousal, and genitopelvic pain/penetration disorders (1). Healthy sexual functioning is a major indicator of a healthy mental function. Negligence of sexual desire leaves irreparable effects on humans. The physical and psychological pressures caused by poor sexual satisfaction lead to sexual deviation and health problems (2). While sexuality is critically important in couples' marital satisfaction, sexual problems are inevitable in any marriage.
They may negatively affect marital satisfaction, cause conflicts, and ultimately lead to divorce (3,4). FSD is a common problem experienced by nearly 40-45% of women (5). According to a study conducted in Australia, 36% of women report at least one new SD in a span of 12 months (6). A similar rate (31.5%) was reported in a study of Iranian women aged 20-60 yr (7). In another study, it was reported as 20-40% (8). The existence of disorders in sexual desire, arousal, lubrication and orgasm in reproductive aged women has been documented by a previous study (9). Based on the available research, 30-60% of women experience SD at least once in their lives (4). A study on 821 women in Iran found the absence of sexual pleasure and orgasm in the sexual lives of 39% and 10.5% participants, respectively (10). Another study estimated the prevalence of anorgasmia in Iranian women at 27% (11). A variety of factors including mental health, sexual relationships, partner's sexual function, personality-related factors, duration of the relationship, infertility, drugs, chronic diseases, pelvic surgery, cancers, and postpartum changes can affect women's sexual function (12,13). Other factors, such as hormonal changes, menstruation, lactation, menopause, and multiple births, may also have significant effects on women's sexual function (5). Also, the literature confirms that SD is associated with mental health problems, including depression and anxiety. This may be due to their lower ability to find an intimate partner, less social integration, and generally lower performance (14). Despite efforts to control sexual problems during the past decades, the existing statistics indicate the relatively unchanged high prevalence and extent of SD among women throughout the world (15). Considering the importance of sexual disorders as a health concern and an important factor affecting the quality of life of couples and the high and variable incidence of SD among reproductive-age women, this study used a meta-analysis to evaluate the prevalence and determinants of SD in Iran and other countries.
The aim of this study was to evaluate the prevalence of SD and its most important risk factors in women of reproductive age using the worldwide review studies.

Search strategy
The current study was a systematic review and meta-analysis reported based on the preferred reporting items for systematic OR "sexual problem" AND "women" OR "reproductive age women" OR "fertility age women."

Study selection
All extracted articles were entered in Endnote Blinding and task separation was applied in the study selection procedure. The inter-rater agreement was 87%.

Quality assessment
The studies included in this review were assessed by two quality assessment The "metabias" command was applied to check the publication bias, and if there was any publication bias, the prevalence rate was adapted with the "metatrim" command using trim-and-fill method (19). In all analyses, a significance level of 0.05 was rated.  and South America (n = 1). The prevalence of SD was reported in all studies. Table II shows the most important risk factors of SD in

Discussion
Sexual relations are essential for human survival and reproduction and have major spiritual and cultural connotations. According to the World Health Organization, SD is a "disorder in sexual desire and the psychophysiological transforms that defined the sexual response cycle and which results in signed distress and relational problem" (41). SD may involve dyspareunia, sexual desire and arousal disorders, and orgasmic dysfunction. These are all major public health issues with considerable negative effects on a person's daily life (42). Nationwide policies to resolve such issues cannot be developed unless the prevalence rate of SD is known. An increasing number of population studies have evaluated FSD under various cultural settings during the past decade. The aim of this systematic review is to provide an overview of the prevalence of FSD among women of reproductive age in different countries, cultural backgrounds, and age groups. It is hoped that the results would better clarify the effects of FSD on women's lives. Since the sexual behavior in Iran has become a taboo due to the historical, cultural, and religious reason and religious prohibitions, it isn't easy for women to talk about it; so dealing with the issue of sexual needs has always been accompanied by shame and anxiety. Further studies in this field are necessary to better understand the challenges (9).
While a larger number of studies were available, they were not included in the analysis as they had applied other tools for the assessment of FSD or did not have an accessible full-text. Moreover, only studies on samples of women have entered the analysis. Based on the obtained results, the FSD had a very high prevalence rate and affected about 51% of women. A meta-analysis by Hosseini Tabaghdehi and coworkers reported the prevalence rate of FSD as 48% (34). In a review study, Aggarwal and coworkers calculated the prevalence rate of SD as 55.6% (43).
In this study, the arousal disorder had the greatest prevalence (about 48%). Pain and disorders in sexual desire, lubrication, orgasm, and sexual satisfaction had prevalence rates of 39%, 51%, 38%, 40%, and 35%, respectively. Ramezani and coworkers found disorder in sexual desire as the most prevalent (65.8%) form of SD. They reported the prevalence rates of sexual pain, arousal disorder, and orgasmic disorder as 35.2%, 59.6%, and 35.2%, respectively (9). In a review study, Aggarwal and coworkers highlighted the orgasmic disorder as the most prevalent (91.7%) form of SD. Moreover, lubrication disorder affected 19% of the women (43).
In the present study, increasing age and duration of marriage increased the prevalence of different forms of FSD, that is, pain and disorders in desire, arousal, lubrication, orgasm, and satisfaction. Also, the increase in age affects the sexual response cycle and the physiology of marital affection and creates hormonal changes. As a result, sexual desire and frequency decrease, which ultimately leads to a reduction in marital satisfaction (44).
Other factors increasing the prevalence of FSD included depression, low education, and chronic illnesses. Convery and coworkers reported that women with a higher educational level had a lower SD and attributed this to reasons such as increased awareness and less negative attitudes (45). Also, chronic diseases due to decreased physical strength, reduced ability to perform daily activities, hospitalization, and, eventually, depression caused by the disease can be a major contributors to sexual problems (46). On the other hand, depressed people experience persistent insensibility, more frustration, helplessness, worthless, guilt, and generally lose their attachment to life, work, and even sex (47).
In this meta-analysis, we only focused on studies evaluating the prevalence of SD in women of reproductive age. While the different prevalence of FSD in various populations may demonstrate the effects of conditions (e.g., culture) on sexual problems, they may also be caused by women's unwillingness to discuss their sexual problems, their perception of sexual problems, and the prevailing sexual culture in different countries. Nevertheless, considering the high prevalence of SD in many countries including Iran, and since SD has a significant impact on marital satisfaction, the intimacy between couples and their quality of life, healthcare providers are recommended to provide women of reproductive age with SD-related advice and counseling to promote public health and marital satisfaction. A limitation of this study was collecting data from cross-sectional studies performed only on women of reproductive age. Moreover, as women might be unwilling to respond to questions about their private sexual life, the results obtained by the reviewed studies may be inaccurate. Furthermore, only studies using the FSFI were included in this systematic review and based on this questionnaire, we classified SD into six domains (hypoactive desire disorder, arousal disorder, orgasmic disorder, dyspareunia, lubrication disorder, and satisfaction disorder). The diagnostic and statistical manual of mental disorders (DSM5) has classified SD into three domains: sexual interest/arousal, genito-pelvic pain/penetration, and orgasmic disorder. This may be the most important limitation of our study. Finally, the education level of the respondents (which might have affected their responses to the items in the questionnaire) was not considered in the selected studies. One of the strengths of this study is an exclusive review of studies that only used the FSFI questionnaire, as well as the examination of studies that were conducted only on women of reproductive age, which reduces the bias.

Conclusion
The prevalence of SD varies in women of reproductive age in different countries. Considering the importance of female SD, further studies are needed to facilitate the development of relevant educational interventions.