AMH Reference Range for a 31-Year-Old Woman
For a 31-year-old woman, the normal AMH reference range is approximately 1.0–5.0 ng/mL (7.14–35.7 pmol/L), with a median around 2.5–3.5 ng/mL, though significant inter-individual variation exists even among healthy, fertile women. 1, 2
Age-Specific Context for AMH Interpretation
AMH levels peak around age 15.8 years, remain relatively stable until approximately age 25, then begin a progressive decline throughout the reproductive years. 3
At age 31, a woman is in the early phase of age-related AMH decline, where levels typically fall within the mid-range of reproductive-age values. 2, 4
Population-based studies show that at ages 30–35, the 50th percentile (median) AMH is approximately 2.5–3.5 ng/mL, with the 25th percentile around 1.5–2.0 ng/mL and the 75th percentile around 4.0–5.0 ng/mL. 1, 2
Critical Interpretation Considerations
Age-specific reference ranges are vital for AMH interpretation, as levels vary dramatically across the lifespan and cannot be assessed using a single universal cutoff. 5, 6
The 5th percentile for women in their early 30s is approximately 0.5–1.0 ng/mL, while the 95th percentile extends to 6.0–8.0 ng/mL. 1, 2
Considerable inter-individual variation exists at any given age, even among healthy, fertile women with regular menstrual cycles. 3, 1
AMH values below 1.0 ng/mL are generally considered low for this age group and may indicate diminished ovarian reserve, though this does not necessarily predict fertility in the general population. 6, 7
Technical and Clinical Limitations
Significant technical issues exist with AMH assays, including lack of international standardization and variability in sample handling, which can affect result interpretation. 5, 6
Different assay platforms (Gen II ELISA, Elecsys, etc.) may yield different absolute values, making it essential to use assay-specific reference ranges. 6
AMH measurement is not appropriate for diagnosing premature ovarian insufficiency, as its diagnostic value remains unestablished in this context. 5
While AMH represents the best endocrine marker for assessing age-related decline in ovarian reserve, it should not be used as a standalone "fertility test" in the general population. 5, 7
Common Clinical Pitfalls
Do not interpret AMH using cutoffs derived from the 95th percentile, as these are not valid biological thresholds for clinical decision-making. 6
AMH levels are independent of BMI, smoking status, and parity, so these factors should not influence interpretation. 1
AMH does not predict time-to-pregnancy or fecundability in women under 40 years attempting natural conception, despite being a marker of ovarian reserve. 7
Values should be interpreted in the clinical context of menstrual regularity, reproductive goals, and other markers of ovarian function rather than in isolation. 5, 6