Ovarian reserve testing is a fertility assessment tool used to estimate the quantity and, indirectly, the quality of a woman’s remaining oocytes. Since women are born with a fixed number of eggs that declines over a lifetime, this testing provides a snapshot of the current follicular pool size. Results from ovarian reserve testing help healthcare providers counsel patients and determine appropriate treatment strategies for those seeking to conceive.
Clinical Reasons for Ovarian Reserve Testing
Testing for ovarian reserve is typically recommended when a patient presents with specific risk factors or is planning certain reproductive procedures. One common indication is advanced maternal age, generally considered 35 years or older, as the decline in egg quantity and quality accelerates significantly after this age. Testing is also often part of the initial evaluation for unexplained infertility in couples who have been trying to conceive without success.
Patients with a medical history that may have impacted ovarian function are also candidates for testing. This includes those who have undergone prior ovarian surgery, such as for endometriosis or ovarian cysts, or individuals exposed to chemotherapy or pelvic radiation. A family history of early menopause is another factor that prompts an ovarian reserve assessment.
For patients planning to use assisted reproductive technologies (ART), such as in vitro fertilization (IVF) or egg freezing, ovarian reserve testing is a routine step. The results help clinicians customize the medication protocols and stimulation dosages.
The Standard Methods of Measurement
Ovarian reserve is evaluated using a combination of blood tests that measure hormone levels and a specialized ultrasound scan. Anti-Müllerian Hormone, Follicle-Stimulating Hormone, and Antral Follicle Count are the three standard markers used to gauge the remaining follicular pool. Each test provides a different, yet complementary, piece of information about ovarian function.
Anti-Müllerian Hormone (AMH)
Anti-Müllerian Hormone (AMH) is a hormone produced by the granulosa cells of small, developing follicles within the ovaries. This hormone is measured through a simple blood test that can be performed at any time during the menstrual cycle, as its levels remain relatively stable throughout the month. Since AMH production directly correlates with the number of these small follicles, the test offers a reliable, direct estimate of the overall ovarian reserve.
Follicle-Stimulating Hormone (FSH)
Follicle-Stimulating Hormone (FSH) is a hormone released by the pituitary gland that signals the ovaries to begin maturing an egg. This blood test is typically performed on day three of the menstrual cycle, when hormone levels are at a baseline. Elevated FSH levels indicate that the brain is working harder to stimulate the ovaries, which is an indirect sign of a lower ovarian reserve.
Estradiol (E2)
Estradiol (E2), a form of estrogen, is measured alongside FSH, also on cycle day three. High levels of E2 early in the cycle can artificially suppress the FSH result, potentially masking an underlying issue with ovarian function. Therefore, the E2 measurement acts as a necessary check to ensure the FSH reading accurately reflects the body’s baseline state.
Antral Follicle Count (AFC)
The Antral Follicle Count (AFC) is a physical assessment performed using a transvaginal ultrasound. During the procedure, the clinician counts the number of small, fluid-filled sacs, called antral follicles, that are visible on both ovaries. These follicles, typically 2 to 10 millimeters in diameter, represent the pool of eggs available for recruitment in that cycle.
Understanding and Interpreting Test Results
The numerical results from ovarian reserve tests are interpreted in conjunction with a patient’s age. Generally, a normal AMH level is considered to be between approximately 1.0 and 3.5 nanograms per milliliter (ng/mL), though this range varies by age and laboratory. An AMH value below 1.0 ng/mL is considered low, suggesting diminished ovarian reserve.
A normal Day 3 FSH level is typically less than 10 mIU/mL, and levels above this threshold indicate that the ovaries are less responsive to stimulation. For the Antral Follicle Count, a sum of 7 to 20 total follicles across both ovaries is considered a normal range, with counts below six suggesting a reduced reserve. Low results in one or more of these tests predict a reduced yield of eggs during fertility treatments like IVF.
Conversely, a very high AMH level or a high AFC (greater than 20 follicles) may suggest the presence of Polycystic Ovary Syndrome (PCOS). These high values reflect an excessive number of small follicles, which can disrupt normal ovulation. Interpreting these results helps specialists counsel patients on the risk of complications, like ovarian hyperstimulation syndrome, during fertility treatment.
The Predictive Value and Limitations of Testing
Ovarian reserve testing provides valuable information, but it is important to understand what the results do and do not predict about overall fertility. The primary value of AMH and AFC lies in their strong ability to predict how the ovaries will respond to stimulation medications during ART. These tests are less effective at predicting a woman’s ability to conceive naturally.
A low ovarian reserve result does not necessarily equate to zero chance of natural conception. The tests measure the quantity of the remaining egg supply, but they are poor predictors of egg quality, which is the most significant factor in achieving a successful pregnancy. Since egg quality declines naturally with age, a young woman with a low egg count may still have a better chance of success than an older woman with a similar count.
A low ovarian reserve result should not be interpreted as a final deadline for childbearing. Ovarian reserve testing serves as a tool for personalized counseling, helping patients and doctors determine the urgency of treatment and the most appropriate therapeutic path. Consulting with a fertility specialist is an important step to ensure the test results are placed into the proper context of a patient’s complete reproductive health profile.