This study was a case-control study involving 180 infertile women who referred to infertility clinics in Ahvaz, Iran. The study commenced in October and concluded in November 2020. The design of the study was approved by the Ethics Board of the Ahvaz Jundishapur University of Medical Sciences (Ref: IR.AJUMS.REC.1399.073). This study was conducted in two infertility clinics in Ahvaz.
In this study, we recruited infertile women with a history of recurrent implantation failure (90) and infertile women with no recurrent implantation failure (n=90). Inclusion criteria were as follows: age between 18 and 45 years, basic literacy, at least one year has passed from the infertility, without any history of implantation failure for the control group and history of at least two or more implantation failures for the case group. The exclusion criteria were as follows: women who were taking medication that had an effect on sexual function, psychological disorders and diseases that had effect on sexual function. Prior to the data collection, written informed consent was obtained from each participant and anonymity of participants was maintained.
The sample size of this study was calculated from the previous study (20) and based on the following formula:
Considering 90% power for this study the final sample size in each group calculated to be 90 women.
To collect data, we used a demographic questionnaire and the Female Sexual Function Index. The demographic questionnaire included questions about age, age of husband, occupation, educational attainment and the economic status. The Female Sexual Function Index contains 19 questions. Two questions have been provided to measure sexual desire, four for sexual arousal, four for lubrication, three for orgasm, three for satisfaction, and three for measuring pain. The score for each domain was multiplied by a certain factor: 0.6 for desire, 0.3 for arousal and lubrication, and 0.4 for other domains. The minimum and maximum rating for all areas is 2 and 36, respectively (21). Scores below 26.5 are considered reduced sexual function. The Persian version of this questionnaire is available, and its validity and reliability have proven in other studies (22).
All women requested to complete both questionnaires, when one of the researchers (SG) was available, if participants had any questions.
The data was analyzed using SPSS version 22. The Shapiro-Wilk test was used to test the normal distribution of data. The independent t-test and Chi-Square tests were used for numerical and categorical data respectfully. The Linear regression was used to detect relationship between RIF and sexual function when adjusted for confounding variables. In all cases, we have considered the significance level as ≤ 0.05.