DURATION OF CONTRACEPTIVE USE IS NOT ASSOCIATED WITH AMH LEVELS

Abstract

To estimate the effect of length of contraceptive use on anti-Mullerian hormone (AMH) levels in reproductive-age women. Prospective analysis of serum AMH levels and survey data. The study included a subset of customers who used an at-home fertility hormone test between June 2018 and April 2020 (n = 2,358). Participants were between 21 and 46, consented to research, had not reported a previous diagnosis of polycystic ovary syndrome or primary ovarian insufficiency, and were currently using either the levonorgestrel IUD (LNG-IUD), implant, combined oral contraceptive (COC), or vaginal ring. The duration of contraceptive use was self-reported and ranged from 1-3 months up to more than 20 years. We performed three linear regressions per contraceptive method to evaluate the relationship between the length of contraceptive use and log-transformed AMH levels. Since three regressions were run per contraceptive group, the threshold for statistical significance (α = 0.05) was set to 0.017 to adjust for multiple comparisons. We subsequently grouped short-term use and long-term use participants into binary categories or bins and compared mean AMH levels for each contraceptive use group. Our cohort included 807 women using the LNG-IUD, 112 using the implant, 1,109 using a COC, and 165 using the vaginal ring. There were no statistically significant associations between length of contraceptive use and adjusted AMH levels for any contraceptive method. This was true in regressions of the entire sample and when we limited the sample to just short-term users or just long-term users. When the length of contraceptive use was treated as a binary variable (short-term <1 year or long-term 1+ years) or was grouped into categories spanning approximately 5 years, no statistically significant effects were observed for any contraceptive method. It is known that AMH levels are lower in women using hormonal contraceptives when compared to women who aren’t. However, this study shows that the duration of contraceptive use is not associated with any additional variation in AMH levels. We observe no impact of either long or short term usage on AMH levels for any of the contraceptive methods included in this study. These results are reassuring since it is still widely believed among physicians and patients alike that long term contraceptive use suppresses ovarian reserve more than short term use, particularly in users of COC.