Abstract
• AMH is considered to be a stable serum biomarker of ovary antral follicle counts.
• AMH is thought to decline over time due to age-related decline in ovarian reserve.
• Some patients with low-range AMH can have normal levels on subsequent blood tests.
• AMH levels decline over time in women older than 35 years of age.
• AMH can fluctuate in either direction over time in women below 30 years of age.
Research Question: Is it possible for a patient to have low AMH readings that recover to normal levels over the space of months or 1-2 years?
Design: Retrospective analysis of fertility clinic patient database. Patients with repeat blood samples were examined to determine the degree of change in AMH levels over time. The main analysis consisted of 1871 patients.
Results: In patients with low AMH (<1.5 pmol/L) at the time of their first blood test, 42% had risen above this threshold at the time of their second blood test. In blood tests taken <6 months apart, AMH levels were equally likely to increase or decrease over time. Over longer timeframes, AMH levels were more likely to show decreases, but this effect was strongest in women over 30 years-old and minimal in women under 30. Patients in the interquartile range are likely to show <5 pmol/L AMH fluctuation in tests taken <2 years apart. However, this also shows that larger changes can be expected in a sizeable minority of patients.
Conclusions: Serum AMH in younger patients tends to fluctuate without substantial declines over time. In older patients, samples taken within 6-12 months tend to fluctuate in either direction, but declines are more likely over longer timeframes. This study demonstrates that a small proportion of patients will have transiently depressed AMH levels, but it is possible for levels to recover in some cases.