Anti-Müllerian Hormone (AMH) has become a widely used diagnostic tool in fertility assessment. This simple blood test offers insight into a person’s ovarian reserve, which is the estimated quantity of eggs remaining in the ovaries. Understanding the result is an important step for anyone planning a pregnancy, especially for those considering fertility treatments or wishing to delay conception. The hormone level provides a valuable snapshot of the reproductive timeline, helping individuals and specialists make informed decisions. This information is particularly relevant when interpreting results in picomoles per liter (pmol/L).
Defining AMH and Its Role in Fertility
Anti-Müllerian Hormone is a protein exclusively produced by the granulosa cells that line the small follicles in the ovaries. These follicles house the immature eggs, and AMH levels reflect the size of the pool of these growing follicles. The hormone acts as a measurable proxy for the total number of primordial follicles, commonly referred to as the ovarian reserve. AMH is secreted by preantral and small antral follicles, which represent the remaining potential egg supply.
The concentration of AMH measures egg quantity, not egg quality. Levels generally remain stable throughout the menstrual cycle, making it a convenient marker that can be tested at any time. A decline in AMH levels reflects the natural, age-related decrease in the number of eggs available. This makes it a useful indicator for predicting the ovarian response to stimulation medications during fertility treatments.
Interpreting AMH Levels in pmol/L
The measurement of AMH is often reported in either nanograms per milliliter (ng/mL) or picomoles per liter (pmol/L). To convert between the two, 1 ng/mL is approximately equal to 7.14 pmol/L. Clinics use specific thresholds in pmol/L to categorize the ovarian reserve.
A typical AMH level for a fertile person is above 16.2 pmol/L, suggesting a satisfactory ovarian reserve. High AMH levels, greater than 22 pmol/L, may indicate an increased number of follicles. While this suggests a strong egg supply, it can also be associated with Polycystic Ovary Syndrome (PCOS).
Levels indicating a low ovarian reserve are typically below 5.5 pmol/L, and a very low result is under 4.9 pmol/L. These lower numbers suggest a reduced number of remaining eggs, which may shorten the reproductive window. A low AMH result does not necessarily predict infertility or the inability to conceive naturally.
Instead, a low AMH primarily indicates that the ovaries may respond poorly to the stimulation drugs used in treatments like In Vitro Fertilization (IVF). For individuals undergoing IVF, the AMH level helps specialists tailor medication dosages to prevent either a poor response or Ovarian Hyperstimulation Syndrome (OHSS). AMH levels must always be interpreted in the context of the individual’s age, as age remains the most reliable predictor of egg quality and natural conception success.
Factors That Influence AMH Results
While AMH provides an estimate of egg quantity, several factors beyond the actual number of eggs can influence the test results. Age is the most significant variable, as AMH levels naturally decline as a person gets older, with the steepest drop occurring after the mid-thirties. This decline reflects the continuous depletion of the ovarian follicle pool over time.
Certain medications can temporarily suppress AMH readings, creating a misleadingly low result. Hormonal birth control, for example, has been shown to artificially lower AMH levels by up to 30% in some studies. These levels typically recover once the contraceptive is discontinued.
Chronic medical conditions also affect AMH concentrations. Polycystic Ovary Syndrome (PCOS) is associated with elevated AMH levels due to the presence of numerous small follicles arrested in their development. Conversely, factors like Vitamin D deficiency, endometriosis, or previous ovarian surgery can lead to lower-than-expected AMH readings. These external influences underscore why the test result should not be viewed in isolation.
Next Steps After AMH Testing
Receiving an AMH result is usually the beginning of a more comprehensive fertility assessment. The most important step after testing is to consult with a reproductive endocrinologist or fertility specialist. These experts integrate the AMH result with other diagnostic information to create a full picture of reproductive health.
A complete evaluation typically includes a transvaginal ultrasound to perform an Antral Follicle Count (AFC), which is a direct count of the small follicles visible in the ovaries. Blood tests for other hormones, such as Follicle-Stimulating Hormone (FSH) and estradiol, are also commonly ordered. The combination of AMH, AFC, and other hormone levels allows for a more accurate assessment of the functional ovarian reserve.
Based on the full set of results, a specialist can provide personalized guidance regarding conception timelines. For those with low AMH, this might involve discussing attempting conception sooner or exploring fertility preservation options, such as egg freezing. Treatment options like IVF, or the potential need for donor eggs, are part of the conversation, especially if other factors indicate a poor prognosis. The overall goal is to formulate a proactive medical pathway that aligns with the individual’s family planning goals.