A low Anti-Müllerian Hormone (AMH) result can be unsettling for anyone considering future fertility. AMH is a hormone produced by the small, developing follicles within the ovaries. Measuring AMH levels in the blood is a common way for specialists to assess a woman’s ovarian reserve, which is the remaining supply of eggs. While a low result often raises fears about infertility, the relationship between this hormone level and the ability to conceive is more nuanced than a simple pass-or-fail test.
What AMH Measures
AMH is a protein secreted by the granulosa cells surrounding eggs in the pre-antral and small antral follicles of the ovaries. The amount of AMH released is directly related to the number of these small follicles present, making the hormone a reliable marker for estimating the size of the ovarian reserve. AMH levels remain stable throughout the month, allowing the blood test to be performed at any point in the menstrual cycle, unlike other reproductive hormones.
The primary function of AMH in the adult female is to regulate the recruitment of primordial follicles, controlling the pace at which the egg supply is utilized. Levels are generally highest in a woman’s twenties and naturally decline with age until becoming nearly undetectable at menopause. A low AMH result is typically defined as a level below 1.0 nanogram per milliliter (ng/mL), suggesting a diminished ovarian reserve.
The drop in AMH is most frequently due to the natural aging process, but other factors can cause an accelerated decline. These non-age-related causes include previous ovarian surgery, which can damage ovarian tissue, or conditions like endometriosis. Low AMH indicates a smaller quantity of eggs, but this measurement does not reflect the genetic quality of the remaining eggs.
Low AMH and the Likelihood of Conception
The distinction is that AMH measures egg quantity and not egg quality, which is the most significant factor in achieving a healthy pregnancy. While a low AMH level confirms a reduced ovarian reserve, it does not automatically equate to infertility, especially for younger individuals. Conception requires only one healthy egg, and a low AMH level does not prevent the monthly selection of a single dominant follicle for ovulation.
For women who are ovulating regularly and do not have other fertility concerns, studies show that the natural pregnancy rate can be similar to that of women with normal AMH levels. The ability to conceive naturally is more strongly correlated with the woman’s age and resulting egg quality than with the total number of eggs remaining. Age is the most reliable predictor of egg quality and the chances of natural conception.
Low AMH becomes a stronger predictor in the context of assisted reproductive technologies, such as In Vitro Fertilization (IVF). Specialists use AMH primarily to anticipate how the ovaries will respond to stimulating medication. A lower AMH score suggests a lower response, meaning fewer eggs are likely to be retrieved in a cycle.
To gain a complete picture of ovarian function, AMH results are always interpreted alongside other markers. These include the Antral Follicle Count (AFC) seen on ultrasound and the Follicle-Stimulating Hormone (FSH) blood level.
Assessing Fertility and Next Steps
A low AMH result signals that the time frame for conception may be shorter, making prompt consultation with a fertility specialist advisable. The specialist will use the AMH level as one piece of information in a comprehensive fertility assessment. This evaluation typically includes a transvaginal ultrasound to determine the Antral Follicle Count (AFC).
Further testing will also measure other hormones, such as FSH and estradiol, which are typically checked early in the menstrual cycle. The overall assessment often includes an evaluation of the fallopian tubes and a semen analysis for a male partner.
For those actively trying to conceive, the management strategy may involve focusing on timed intercourse or moving directly to assisted reproductive techniques like IVF. If pregnancy is not desired immediately, a low AMH result may prompt a discussion about fertility preservation options, such as egg freezing.
Ultimately, a low AMH level serves as an important call to action for a thorough and timely discussion with a reproductive health expert.