The estimated prevalence of infertility is approximately
9% worldwide (
Sexual dysfunction has several domains. The Diagnostic
and Statistical Manual of Mental Disorders (DSM-5)
lists the types of sexual dysfunctions in females as female
sexual interest/arousal disorder, female orgasmic
disorder, and genito-pelvic pain/penetration disorder
There is an association between sexual dysfunction
and infertility (
Many studies conducted in Iran to evaluate the prevalence
of sexual dysfunction among infertile women have
reported various findings (
Royan Institute approved this systematic review and
meta-analysis (code: 95000051). The authors followed
the Preferred Reporting Items for Systematic Reviews
and Meta-Analyses (PRISMA) checklist to perform this
Studies with the estimated prevalence rates of FSD, observational studies, studies in Farsi and English languages, and those without any restricted published date were included in this study. Excluded from this meta-analysis were interventional studies, repeated or duplicated studies, and studies with no relevant reported data.
In this meta-analysis, 2 authors (AAH and SM) separately extracted the required data from the included studies. Data extracted were: first Authors' name, year of publication, place of study, published year of study, mean age, infertility year, sample size, type of questionnaire, and the prevalence estimate of FSD and its dimensions. Then, 2 reviewers (AAH and MS) independently performed the quality assessment based on our modified STROBE checklist (
The pooled prevalence was estimated by the “metan” command in Stata. Statistical heterogeneity between studies was checked by the Cochrane Q test and I2 statistics. Because of low primary studies, for the Cochrane Q test, we considered a P<0.10 to be statistically significant. An value of 25% indicated low heterogeneity, 50% was moderate, and 75% indicated high heterogeneity (
The outcome measure of study was prevalence of sexual dysfunction in infertile women. In terms of the outstanding heterogeneity among the studies, we applied a random effect model to pool the primary prevalence rates. To explain the sources of between-study heterogeneity, meta-regression was performed for the year of the study, the sample size, and type of questionnaire. By running the “metainf” command, we conducted sensitivity analyses by excluding each study from the analysis to examine the influence of each study on the pooled estimate. The Funnel plot, Begg's rank correlation, and Egger's weighted regression tests were used to assess publication bias (
The details of the study selection method are shown in Figure 1. We identified a total of 313 relevant papers; after removal of the duplicates, 271 papers remained. After screening the titles and abstracts, we disqualified 228 papers, and resumed the full texts for 43 relevant papers. Next, we excluded all non-eligible studies, which left a total of 18 cross-sectional or case control studies based on the inclusion criteria for the meta-analysis.
Flow diagram of the literature search for studies included in the meta-analysis.
The majority (two-thirds) of the studies used the FSFI questionnaire to assess the prevalence of FSD. The lowest prevalence of FSD among infertile women was 46.6%, whereas the highest prevalence of FSD was 87.1%. These studies were published between 2001 and 2017 and had a diverse sample size that ranged from 30 to 604 cases, with a total of 3419 infertile women. Additional information about each primary study included in this analysis is shown in Table 1.
Characteristics of the primary studies included in the meta-analysis
|ID||Author||Yearpublished||City||Samplesize||Age (Y)(mean + SD)||Mean years of infertility (mean + SD)||Questionnaire||Sampling method||Quality assessment|
|1||Sargolzaee et al. (24)||2001||Mashhad||30||25.77 ± 5.08||4.2 ± 3.09||GSF||Random||Moderate|
|2||Besharat and Hoseinzadeh Bazargani (25)||2006||Tehran||45||28.8 ± 4.68||NA||Golombok-Rust||Convenience||Low|
|3||Tayebi and Yassini Addakani (26)||2007||Yazd||300||27.93 ± 4.8||5.42 ± 3.2||NR||Volunteer||Moderate|
|4||Khademi et al. (27)||2008||Tehran||100||26.9 ± 5||5.3 ± 3.7||SFQ||Volunteer||Moderate|
|5||Fahami et al. (28)||2009||Isfahan||140||29 ± 5.5||6.5 ± 5.2||FSFI||Convenience||Moderate|
|6||Pakpour et al. (8)||2012||5 cities||604||30 ± 7.8||NA||FSFI||Convenience||High|
|7||Aghamohammadian Sharbaf (29)||2014||Mashhad||200||28.8 ± 6.2||NA||FSFI||Convenience||Moderate|
|8||Basirat et al. (30)||2014||Babol||208||27.85 ± 5.7||NA||FSFI||NA||High|
|9||Davari Tanha et al. (11)||2014||Tehran||320||29.66||NA||FSFI||NA||Moderate|
|10||Hashemi et al. (31)||2014||Tehran||128||30.9 ± 4.9||NA||FSFI||NA||Moderate|
|11||Jamali et al. (32)||2014||Jahrom||100||28.56 ± 5.72||NA||FSFI||Random||High|
|12||Jamali et al. (33)||2014||Jahrom||502||30.95 ± 6.80||NA||FSFI||Convenience||Moderate|
|13||Karamidehkordi and Roudsari (34)||2014||Mashhad||130||27 ± 4.58||NA||FSFI||Convenience||Low|
|14||Alirezaee et al. (35)||2014||Mashhad||85||NA||NA||FSFI||Convenience||Low|
|15||Bakhtiari et al. (36)||2016||Babol||236||26.1 ± 5.3||60.2 ± 8.4 months||DSM||Convenience||Moderate|
|16||Mirblouk et al. (37)||2016||Guilan||147||31.66 ± 6.8||NA||FSFI||NA||Moderate|
|17||Zare et al. (38)||2016||Mashhad||110||29.2 ± 4.9||4.85 ± 3.53||Golombok-Rust||Convenience||Moderate|
|18||Billar et al. (39)||2017||2 cities||34||42||NA||FSFI||Convenience||Low|
GSF; Global Sexual Functioning Scale, SFQ; Sexual Function Questionnaire, FSFI; Female Sexual Function Index, NR; Not reported, and DSM; The diagnostic and statistical manual of mental disorders.
The results of Cochran’s Q test and I2 statistics displayed considerable heterogeneity among the primary studies included for FSD (Q=194.04, P=0.0001 and I2: 95.4%); thus, we used the random effects model for analysis. The pooled prevalence of FSD was 64.3% (95% CI: 53.3-75.3). As shown in Figure 2, the lowest prevalence of FSD was reported by Basirat et al. (
Forest plot that shows the prevalence of female sexual dysfunction (FSD) among infertile Iranian women.
The pooled estimated prevalence of different dimensions of sexual dysfunction that included sexual desire, sexual excitement, orgasm, dyspareunia and vaginismus is presented in Table 2. The results showed that the most prevalent sexual disorder was related to sexual desire (59.9%; 95% CI: 38.7-81.2) and the least prevalent was vaginismus (19.2%, 95% CI: 11.3-27.2).
The pooled estimated prevalence of different dimensions of sexual dysfunction
|Disorder||Number of included studies||Pooled estimated (%)||95% CI||I2 (%)|
CI; Confidence interval and I2; I square.
We used Begg’s test to assess for probable publication bias of FSD prevalence. The results showed no evidence of any publication bias (P=0.325).
In order to assess the sources of heterogeneity, we included 4 variables in a univariate meta-regression. The results suggested that the study sample size (P=0.992), date (P=0.366), type of questionnaire (P=0.418), and age (P=0.070) were not accountable for the heterogeneity in the FSD prevalence. Therefore, we used the random effect model because of the presence of heterogeneity between studies.
In order to calculate the influence of each primary study, a sensitivity analysis was performed by removing each study from the analysis and calculating the point estimates. The results of the sensitivity analysis (
Sensitivity analysis to estimate the pooled prevalence by removal of each individual study
|Study omitted||Pooled prevalence||95% CI|
|Basirat et al. (30)||0.662||0.774||0.550|
|Karamidehkordi and Roudsari (34)||0.653||0.769||0.537|
|Bakhtiari et al. (36)||0.653||0.770||0.536|
|Hashemi et al. (31)||0.652||0.768||0.535|
|Pakpour et al. (8)||0.653||0.770||0.535|
|Tayebi and Yassini Addakani (26)||0.650||0.769||0.530|
|Alirezaee et al. (35)||0.635||0.754||0.515|
|Mirblouk et al. (37)||0.631||0.754||0.509|
|Billar et al. (39)||0.625||0.742||0.508|
|Jamali et al. (33)||0.612||0.678||0.546|
After sorting the studies based on publication year, the cumulative meta-analysis showed that the overall prevalence estimate was not constant over time; rather there was an increase after 2014 (
Cumulative meta-analysis of female sexual dysfunction (FSD) by sorting the studies based on publication time.
The tendency of having sexual intercourse is strongly affected by pregnancy, which results in a low FSD score. It is well-known that infertile women are at a higher risk of sexual dysfunction compared to fertile women (
Although the prevalence of sexual desire was higher than the other dimensions, dyspareunia, orgasm, and sexual excitement did not considerably differ in prevalence ratios. Based on the results of our meta-analysis, the prevalence of FSD among infertile women in Iran was noticeable. This might be due the adverse consequences of infertility such as personal and marital distress, depression, anxiety, reduction in self-esteem, and greater risk of psychological pressure that strongly contributes to sexual dysfunction in women (
Keskin et al. (
There may be a two-way relationship between infertility and sexual dysfunction. Infertility changes sexual feelings and sexual dysfunction may result in infertility. However, numerous potential factors cause the increase in FSD prevalence among infertile women and include involuntary childlessness, woman’s age, husband’s age, the lack of knowledge about marital issues, lack of training in the society, socio-economic status, infertility characteristics, the relationship with partner, duration of marriage, medical problems, depression, anxiety, loss of self-esteem, menopausal status, history of previous infertility treatment, income level, lower educational level, frequency of intercourse, and higher partner education (
Infertility affects the dimensions of sexual dysfunction (
However, the power of statistical tools that has identified the heterogeneity in the studied meta-analysis differs according to the sample size of the studies as well as the number of included studies. The chi-square test is strongly affected by these limitations, such that a non-significant result must not be taken as evidence of lack of heterogeneity. On the other hand, the power of the chi-square test is high when many studies are included in a meta-analysis. The I2 value depends on the magnitude of the prevalence ratios (
Limitations in this study included the use of different questionnaires with different scoring methods to assess the prevalence of sexual dysfunction; therefore, we did not pool all of the scores in a continuous scale. In some studies, the scores of the questionnaires (in a continuous scale) was reported, whereas in other studies, the prevalence of FSD (in a categorized scale) was reported. There were different cut-offs for the questionnaires. For example, the point at which a woman was classified as having a sexual dysfunction or not might have been used in the studies. However, we ignored this issue and pooled the reported prevalence rate.
The results of current meta-analysis discovered that prevalence of FSD in infertile Iranian women was considerable. More than 64% of these women had sexual dysfunction. This study also showed that sexual desire was significantly more common than other sexual dysfunction dimensions and that the prevalence of vaginismus was less than the other dimensions.