Date of Graduation
Bachelor of Science
Health, Human Performance and Recreation
Committee Member/Second Reader
Introduction: Despite intrauterine systems (IUS) being one of the most effective contraception methods available to women, fewer than 6% of women in the United States who use contraceptives rely on IUSs as their primary method. Instead, many women rely on the oral contraceptive pill. The effects of oral contraceptives on sex-hormone (i.e., progesterone, estrogen, androstenedione, and testosterone) levels and their subsequent impacts on sexual function and mood are well-studied; however, the impact of hormonal IUSs on these factors has not been established. This research is important because undesirable changes in sexual function and mood are reported as reasons for discontinuing a contraceptive method. Purpose: The purpose of this study was to explore the fluctuation of sex-hormones (estrogen, progesterone, androstenedione, and testosterone) levels in the blood of IUS users. Secondly, this study aimed to examine the impact of sex-hormone fluctuations on sexual function and mood over a four-week period in women who have had an IUS for a minimum of 12 months. Methodology: This study consisted of women (N=19, aged 18 – 31 years) who had an IUS (Mirena, Skyla, or Kyleena) for at least 12 months prior to participation in the study, were within 80% - 130% of ideal body weight, had a regular sex partner, and were not taking any medications known to impact sexual function or sex hormones. Participants reported to the lab once a week for four consecutive weeks for a total of four visits, between 3 PM and 6 PM. At each lab visit, participants completed the Female Sexual Function Index (FSFI). Participants also provided a blood sample (8.5mL). After the blood sample was obtained, it was allowed to clot for 20 minutes then centrifuged for 15 minutes at 1200 G and 20 degrees Celsius. The blood serum was then removed and stored at -80 degrees Fahrenheit until later analysis. After nineteen participants’ tests were completed, enzyme-linked immunosorbent assays (ELISAs) were run to measure the sex hormones present in the blood. Data were analyzed using an analysis of variance (ANOVA), and significance was set at an alpha of 0.05. P-values between 0.05 and 0.01 were reported as marginally significant. Results: There were no associations between testosterone, progesterone, or estradiol and female sexual function (p > 0.05). Consistent with previous research, androstenedione was associated with changes in vaginal lubrication, F (1.77,31.92) = 5.96, P = 0.008, and a marginally associated with changes to sexual arousal, F (2.13,38.29) = 3.00, P = 0.06 and female orgasm, F (1.96,35.29) = 3.14, P = 0.06. Conclusion: Women using IUS experience great fluctuations in their sex-hormone levels. Despite large fluctuations, testosterone, progesterone, and estradiol were not associated with changes in female sexual function. Fluctuations in androstenedione impacted females’ vaginal lubrication, sexual arousal, and orgasm.
Hormones, sex-hormones, sexual function, IUS, IUD, contraception
Ferguson, K. (2019). Sex-hormone fluctuations and their effects on sexual function in IUS users. Health, Human Performance and Recreation Undergraduate Honors Theses Retrieved from https://scholarworks.uark.edu/hhpruht/73