Comparison of sexual function in infertile women with polycystic ovary syndrome and endometriosis: A cross-sectional study

Abstract Background Infertility is one of the issues affecting sexual function (SF). Infertility is also one of the complications of polycystic ovary syndrome (PCOS) and endometriosis. Objective This research seeks to assess and compare SF and the prevalence of sexual dysfunction in infertile women with PCOS and endometriosis. Materials and Methods A cross-sectional study was carried out with a sample of 630 (210 infertile women with endometriosis, 210 infertile women with PCOS, and 210 healthy women of childbearing age as the control group). SF was assessed by the female sexual function index (FSFI). Descriptive statistics and inferential statistics were used to analyze the data. The primary outcome measured was FSFI score. Secondary outcome was hospital anxiety and depression scale score. Results The results showed that the mean score of the total FSFI in the 2 groups of PCOS and endometriosis was lower than the control group (p < 0.001). In addition, women with higher education (university education) had a higher total FSFI. Conclusion Sexual dysfunction rates are high in infertile women with endometriosis and PCOS. Infertility service providers in infertility centers need to pay attention to this issue.


Introduction
Worldwide estimation of infertility prevalence was 9% and had similar rates in developed and less developed countries (1). The world health organization defines infertility as "a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse" (2). A person with infertility faces complex biological, psychological, social, and ethical problems (3). Infertility is a 2-person problem, and it affects the marital and sexual life of any couple (4). Sexual problems are common in infertile couples and have been reported affecting between 5% and 55% of infertile couples (5). One of the factors affecting infertile women is sexual function (SF), a key factor in physical and marital health and can significantly reduce the quality of life (6).
Endometriosis and polycystic ovary syndrome (PCOS) affect millions of women in the world (7). PCOS is the most common endocrine disorder in women of reproductive age.
Sometimes this syndrome increases anxiety and tension that lead to depression, eating disorders, sexual dysfunction, and so on (8).
Endometriosis is a chronic condition affecting women of reproductive age. It is induced by endometrial-like tissue outside the uterus, which induces a local inflammatory response (9). 32% of participants with endometriosis express sexual problems with intercourse pain, reduced intercourse frequency per month, and feelings of guilt against the partner (10).
In various biological windows in endometriosis and PCOS, several oxidative stress markers have been studied. It have been shown that imbalance in the levels of free radicals and disruptive antioxidants in cellular homeostasis, is supported by higher oxidants and might to reproductive and metabolic complications (7). Multiple studies have shown that oxidative stress also plays an important role in the pathophysiological mechanism of male sexual dysfunction (11)(12)(13).
Based on this fact, it is assumed that oxidative stress may also play a role in the mechanism of female sexual dysfunction (14).
Considering the increasing prevalence of PCOS (from 5-10% revealed by the majority of the studies) (15) and endometriosis (estimated prevalence of 10%) (16) and their impact on fertility and sexual life, this study aims to compare the SF of infertile women having either of these diseases with the control group.

Eligibility criteria
The inclusion criteria were the absence of any other physical diseases (such as heart and kidney diseases, diabetes, high blood pressure, chronic headaches) according to participants' medical records. The control group's inclusion criteria consisted of having at least one alive and healthy child and not being postpartum. Women who did not complete the questionnaires or met the inclusion criteria but refused to continue participation in the study were excluded from the study.

Measures
Participants' demographic and fertility

Depression and anxiety
The hospital anxiety and depression scale is  the study's purposes, written consent and verbal assent were collected from all participants.

Ethical considerations
Women were informed that their participation was voluntary, confidential, and anonymous and they were apprised of their right to withdraw from the research.

Statistical analysis
The collected data were analyzed through descriptive and analytic statistics using Statistical A p-value of < 0.05 was considered statistically significant.

Results
The results of the present study were quantitatively measured and data collection was performed using valid questionnaires. Comparing the mean age of the 3 groups revealed that the mean age of the PCOS group was significantly lower than that of the endometriosis and control group (p < 0.001).
Also, there was a significant difference between the groups regarding the level of education, occupation, and type of infertility (p < 0.001), but the mean BMI, and duration of infertility did not differ significantly between groups (Table I).
Based on one-way ANOVA and the Dennett test (due to the heterogeneity of variances), there were significant differences in the mean score of the total FSFI and its subscales between the 3 groups (p < 0.001). As shown in table II, the mean total score of FSFI in the endometriosis group was significantly lower than PCOS and control groups, and the mean total score of FSFI in the PCOS group was significantly lower than the control group. In the endometriosis group, the score of orgasm, pain, and satisfaction subscales were significantly lower than PCOS and control groups. There were no significant differences in desire, arousal, and lubrication subscales between endometriosis and control group.
The score of desire, arousal, and lubrication subscales in the PCOS group were significantly lower than the endometriosis and control group (p < 0.001). There were no significant differences between PCOS and control groups in the orgasm subscale (Table II).
Our results showed that there was a significant relationship between education and SF, as women with college-level education had significantly lower sexual dysfunction (p < 0.001) (Table III).
Also, a comparison of the mean score of FSFI at different stages of endometriosis showed that the mean scores of FSFI in stage 3 (mean score: 24.1) and 4 (mean score: 22.3) were lower than stage 1 (mean score: 29.1) and 2 (mean score: 26.5) (p < 0.05).

Discussion
Sexual dysfunction is common in infertile couples, which is likely a "side effect" of frustration with their inability to have a child (15). In our study, the mean score of total FSFI in the endometriosis group was lower than in other groups. This A study showed that each domain of the SF (satisfaction, desire, orgasm, and pelvic problem interference) significantly affects endometriosis participants compared to healthy women (8).
Our study observed that in later stages of endometriosis, the total FSFI score was lower.
It was shown in a study that women with deep infiltrating endometriosis have a SF impairment (16).
Various studies revealed that endometriosis has a negative effect on the different dimensions of SF (17)(18)(19). In our study, the mean pain score in the endometriosis group was lower than the control group and the PCOS group. found in the brain and also in genital tissues, suggesting that they are important both in central (desire, arousal) and peripheral SF (27).
In our study, the mean BMI was higher in the PCOS group. A review study concluded that BMI and infertility affected sexuality in women with PCOS (28). In another study, BMI level higher than normal was associated with decreased desire and satisfaction, and education was one of the factors affecting SF in women with PCOS (26).
The result of a meta-analysis was in line with our study conclusion. In this meta-analysis, women with PCOS, their SF and sexual attractiveness were affected (29). The findings of our study were similar to the results of another study (30). In this study,  (23)(24)(25)(26). This is probably due to the search for better health behaviors associated with higher education (27).

Limitations
Female sexual dysfunction is a multidimensional disorder. It is also affected by various factors, especially the marital satisfaction of couples.
Men's SF might affect women's SF. Men's erectile dysfunction, premature, and delayed ejaculation are factors that appear to play a significant role in determining female sexual dysfunction. But we had little information about the female's partners. The large number of samples in each group was the strength of our study.

Conclusion
In the present study, sexual dysfunction in the endometriosis group was less than in the control group and the PCOS group. It was lower in the PCOS group than the control group. Most sexual dysfunction in the endometriosis group was related to orgasm, satisfaction, and pain subscales, and in the PCOS group was related to desire, arousal, and lubrication subscales. Also, in our study, women with higher education level had less sexual dysfunction. Considering the impact of endometriosis and PCOS on the SF of infertile women, attention and assistance in alleviating these participants' sexual problems during the infertility diagnosis and treatment process might improve and maintain their sexual health.