Ovarian reserve markers in women using various hormonal contraceptives

Objectives: The aim of the study was to assess whether the ovarian reserve markers anti-Mullerian hormone (AMH) and antral follicle count (AFC) were lower among women using the progestin-only pill (POP) or levonorgestrel-releasing intrauterine system (LNG-IUS) and similar to the decrease observed in combined oral contraceptive (COC) pill users. Methods: This retrospective study comprised 565 hormonal contraceptive users (COC, POP, LNG-IUS or contraceptive vaginal ring) and 983 non-hormonal contraceptive users, who were seen in two Danish fertility assessment and counselling clinics between 2015 and 2019. Adjusted multiple regression analysis was used to examine the differences in AMH and AFC between hormonal and non-hormonal contraceptive users. Results: Compared with non-hormonal contraceptive users, AMH was 31.1% lower among COC users [95% confidence interval (CI) -39.6%, -25.9%; p < 0.001], 35.6% lower among POP users (95% CI -49.0%, -18.6%; p < 0.001) and 17.1% lower among LNG-IUS users (95% CI -31.4%, 0.002%; p = 0.052); no significant differences were seen among vaginal ring users. Compared with non-hormonal contraceptive users, AFC was 31.3% lower among COC users (95% CI -35.0%, -25.3%; p < 0.001) and 29.7% lower among POP users (-39.1%, -17.9%; p < 0.001); no significant differences were seen among LNG-IUS or vaginal ring users. Ovarian volume was more than 50% reduced among COC and vaginal ring users (p < 0.001) but was unchanged among POP and LNG-IUS users. Conclusion: Assessment of ovarian reserve markers among users of all types of hormonal contraception should be interpreted cautiously and the type of contraceptive method considered.