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

Abstract

Background and objectives: The quality of cervical mucus (CM) among the levonorgestrel-releasing intrauterine system (LNG-IUS) users is controversial. The objectives were to assess CM compared to the levels of oestradiol (E₂) and the frequency of cycles with luteal activity among users of the LNG-IUS.

Materials and methods: In total, 224 LNG-IUS users for between two months and five years were recruited at a Brazilian family planning clinic. For the cross-sectional part of the study, we enrolled 175 LNG-IUS users at 2, 6 12, 24, 36, 48, and 60 months after insertion (25 women in each group), and we performed one evaluation. For the prospective part of the study, we enrolled 49 LNG-IUS users at the same lengths of use after insertion (7 women in each group), and we evaluated these women once a week for five consecutive weeks. _.

Results: Mean (± SEM) CM scores of all evaluations among women with single and weekly evaluations were between 3.3 ± 0.9 and 8.5 ± 0.3, respectively independently of the length of use of the LNG-IUS. Mean E₂ values ranged from 45.5 ± 6.8 to 472.5 ± 34.7 pg/ml and the maximum ovarian follicle diameter on the days of evaluation varied from 14.0 ± 1.3 to 31.2 ± 0.4 mm.

Conclusions: The mean CM score of all evaluations, independent of the length of use of the LNG-IUS and normal levels of serum E₂, was below 10 was according to the WHO is inadequate for sperm penetration.

Chinese abstract

背景和目的：左炔诺酮宫内释放系统(LNG-IUS)使用者的宫颈黏液质量（CM）是有争议的。目的是为了评估与对应的雌二醇水平和黄体活性周期频率相比, LNG-IUS用户的宫颈黏液质量。材料和方法：在巴西计划生育门诊一共募集了224名LNG-IUS用户, 使用时间在2月到5年之间。横断面研究部分中, 我们选取了175名LNG-IUS用户进行评估, 放置时间分别是2, 6, 12, 24, 36, 48和60个月（每组25人）。前瞻性研究部分中, 我们选取49名LNG-IUS用户（每组7人）, 在放置相同的时间后进行每周1次, 连续5周的评估。结果：使用不同时间LNG-IUS的所有女性, 单次和每周进行评估的得分, 其均数（±标准差）cm是在3.3 ± 0.9和8.5 ± 0.3之间。平均E2值范围是从45.5 ± 6.8 to 472.5 ± 34.7 pg/ml , 测评日最大卵泡的直径在14.0 ± 1.3 to 31.2 ± 0.4 mm之间。结论：在使用LNG-IUS不同时间和正常血清E2水平下, 所有的宫颈黏液评分均低于10分, WHO认为精子不足以穿透。

Keywords:

• Cervical mucus
• levonorgestrel-releasing intrauterine system
• ovulation

Disclosure statement

We declare that we have no conflicts of interest regarding this study. Luis Bahamondes acted occasionally at the Board of Bayer. The other authors declare no conflicts of interest.

Funding information

This study received partial financial support from the National Research Council (CNPq), grant #573747/2008-3. The LNG-IUS was donated by the International Contraceptive Access (ICA) Foundation, Turku, Finland under unrestricted grant.