Does a levonorgestrel‑releasing intrauterine device (Mirena) lower anti‑Müllerian hormone (AMH) levels in a 38‑year‑old woman with low AMH (0.033 ng/mL) and elevated follicle‑stimulating hormone (FSH 14–19 IU/L)?

Does Mirena Lower AMH in Women with Diminished Ovarian Reserve?

No, the levonorgestrel-releasing intrauterine device (Mirena) does not lower AMH levels; in fact, evidence suggests it may slightly increase AMH in women with menorrhagia, though this patient's severely diminished ovarian reserve (AMH 0.033 ng/mL) reflects underlying premature ovarian insufficiency that the IUD will not worsen.

Understanding the Clinical Context

This 38-year-old woman presents with laboratory findings consistent with premature ovarian insufficiency (POI): her AMH of 0.033 ng/mL is profoundly low (normal range typically >1.0 ng/mL), and her elevated FSH of 14-19 IU/L confirms ovarian dysfunction 1, 2. These values indicate she has minimal remaining ovarian reserve and is at high risk for early menopause 2.

Key Point About AMH Interpretation

• Very low AMH levels (<0.7 ng/mL) are indicative of incipient ovarian insufficiency, and this patient's value of 0.033 ng/mL places her in the severely diminished category 2
• Her elevated FSH (14-19 IU/L) combined with this extremely low AMH confirms the diagnosis of POI 1, 2

Effect of Levonorgestrel IUD on AMH Levels

Direct Evidence on LNG-IUD and AMH

The levonorgestrel IUD does not decrease AMH levels and may actually increase them slightly:

• A prospective controlled trial of 50 women with menorrhagia showed that 6 months after LNG-IUD insertion, AMH levels increased significantly (p=0.046), along with increases in FSH, antral follicle count, and ovarian volume 3
• The same study demonstrated that LNG-IUD use "effectively improves fertility capacity" with increased AFC and AMH levels 3

Comparison with Other Hormonal Contraceptives

The hormonal IUD has minimal systemic hormonal effects compared to other contraceptive methods:

• A large cross-sectional study of 27,125 women found that hormonal IUD users had only 6.73% lower AMH levels compared to non-users, which was the smallest decrease among all hormonal contraceptive methods 4
• Combined oral contraceptive pills showed 23.68% lower AMH, vaginal rings 22.07% lower, and implants 23.44% lower 4
• The copper IUD showed no significant difference in AMH levels (1.57% lower, p=0.600), confirming that the small decrease with hormonal IUD is minimal 4

Duration of Use Considerations

• Duration of hormonal IUD use showed a slight positive association with AMH levels, though the effect size was small and likely not clinically meaningful 4
• Long-term studies (>1 year) of combined hormonal contraceptives showed marked AMH decline, but this pattern was not observed with the LNG-IUD due to its primarily local rather than systemic effects 5

Critical Clinical Implications

The Real Issue: Underlying POI

This patient's extremely low AMH reflects her underlying ovarian dysfunction, not potential IUD effects:

• With AMH of 0.033 ng/mL and FSH 14-19 IU/L, she already has established POI 1, 2
• Women with severely diminished ovarian reserve (AMH <0.7 ng/mL) have significantly increased miscarriage risk (OR 1.91,95% CI 1.40-2.60) if they do conceive 6
• At age 38 with these laboratory values, she faces imminent risk of complete ovarian failure 2

Counseling Priorities

This patient requires urgent reproductive counseling regardless of contraceptive choice:

• She should be counseled about her extremely high risk of early menopause and the need to expedite childbearing if desired 1, 2
• Referral to reproductive endocrinology is strongly recommended for fertility evaluation and discussion of assisted reproduction options, including potential oocyte cryopreservation if any viable follicles remain 1
• AMH is not affected by exogenous estrogen or progesterone, so her current measurement accurately reflects her ovarian reserve even if she uses the LNG-IUD 1

Contraceptive Considerations

If contraception is needed, the LNG-IUD is actually an appropriate choice:

• The LNG-IUD provides effective contraception without significantly suppressing ovarian function 3, 4
• Women aged >45 years can use the LNG-IUD with the highest safety rating (U.S. MEC 1) based on age alone 7
• The device maintains high contraceptive efficacy through 8 years of use with favorable safety profile 8

Important Caveats

• AMH testing should be interpreted cautiously in women <25 years, but at age 38, this patient's AMH accurately reflects her ovarian reserve 2
• While the LNG-IUD won't worsen her ovarian reserve, it also cannot restore or improve her underlying POI 1, 2
• The slight AMH increase observed in the menorrhagia study 3 likely reflects improved ovarian function from treating the underlying pathology rather than a direct IUD effect
• Contraception may still be necessary despite low AMH, as ovarian function can be unpredictable and spontaneous pregnancy, while unlikely, remains possible 1, 2