Temporal changes in cervical mucus after insertion of the levonorgestrel-releasing intrauterine system

Assessment of the quality of cervical mucus among users of the levonorgestrel-releasing intrauterine system at different times of use

“…Our findings are in agreement with two of the studies, [20,21] and they indicated that the use of an LNG-IUS provoked profound changes in the quality of CM. We evaluated CM, E 2, and ovarian follicular development on the same day and one time each week for five weeks to simulate a normal menstrual cycle because we were unable to identify the day of the menstrual cycle due to the menstrual changes induced by the device.…”

“…[20,21] The first study [20] showed that in 14 LNG-IUS users and 16 non-users, 14% of LNG-IUS and 69% of non-LNG-IUS users had a CM score 10 (p ¼ 0.004); also LNG-IUS users did not present CM-sperm penetration when compared to non-users (0% vs. 64.3%, p < 0.001). The other study [21] analysed CM on days 1, 3, and 5 after Mirena-IUS insertion when it was placed at mid-cycle. At the time of insertion, all participants showed excellent CM scores and sperm penetration; however, from the first day onward, after placement of the device, most of the women presented with poor CM as well as poor sperm penetration.…”

“…Early studies showed inhibition of ovulation through the first year of use; [15,16] however, long-term users had normal ovarian follicular development, [17] and ovarian cysts or persistent ovarian follicles were also reported. [18,19] In addition to the described mechanism of action upon the endometrium level and in ovarian follicular development, it was also described changes in the CM and spermatozoa-CM interactions, [14,20,21] although they remain controversial. [15,17] When characteristics of CM and its interactions with spermatozoa were assessed, a significantly higher CM score was found among non-users as compared to users of the LNG-IUS; good sperm penetration was observed only among non-users of the Mirena-IUS.…”

“…[20] In addition, the CM-spermatozoa interaction was evaluated a few days following the insertion of the LNG-IUS in the middle of the menstrual cycle, and there was both poor CM quality and poor sperm penetration. [21] Due to the scarce information available on CM quality and ovulatory status among short-and long-term users of the LNG-IUS, [15,17,20,21] the objectives of this study were to assess the quality of CM compared to the levels of E 2 and the frequency of ovulatory cycles among users of the LNG-IUS who used the device for between two months and five years.…”

Intravaginal rings as delivery systems for microbicides and multipurpose prevention technologies

“…The systemic levels of LNG found in the 20 μg/d LNG IVR users were in the same low range as those measured among users of the 20 μg/d LNG intrauterine system (IUS) (Mirena®; Bayer HealthCare Pharmaceuticals) (0.2–0.5 ng/mL)61–63 and the 14 μg/d LNG IUS (Skyla™; Bayer HealthCare Pharmaceuticals) (0.1–0.2 ng/mL) 64. These highly effective and acceptable contraceptive products work primarily by exerting local effects on the cervical mucus,65 which we believe will be the primary contraceptive mechanism of action of the proposed TFV/LNG IVR. The additional contraceptive action from the LNG IUS likely results from local effects on the endometrium,63 impairment of the fallopian tube transport of sperm and ova, and some level of ovulation suppression 66.…”