AMH and Antral Follicle Count Before IVF: What They Can and Cannot Tell You

Two tests, one question

"Ovarian reserve" is clinic shorthand for the pool of follicles that could respond to fertility medication. Nobody can count that pool directly, so clinicians use two stand-ins. Anti-Müllerian hormone (AMH) is a blood test. Antral follicle count (AFC) is a transvaginal ultrasound in which the clinician counts the small follicles visible in both ovaries.

Both answer the same practical question: if we stimulate these ovaries, roughly how many eggs should we expect? The American Society for Reproductive Medicine describes the link between these markers and egg yield in IVF as well demonstrated, and calls AMH and AFC the simplest and most sensitive measures of ovarian reserve currently available (ASRM Practice Committee, 2020).

How AMH works as a test

AMH is produced by small growing follicles. Its big advantage for travelling patients is that it does not depend on cycle day. ASRM notes that levels are fairly stable within and between menstrual cycles, so the blood draw can happen at a convenient time at home (ASRM, 2020).

Two cautions apply. First, AMH may be lower in people using hormonal contraception, so a result drawn while on the pill should be read carefully rather than treated as a verdict (ASRM, 2020). Tell the reviewing clinic whether you were using any hormonal method when the blood was taken.

Second, AMH numbers do not travel perfectly between laboratories. ASRM's 2023 OHSS guideline points out that published AMH cut-offs vary from study to study and depend on the assay used (ASRM Practice Committee, 2023). Results can also be reported in different units, such as ng/mL or pmol/L. Check the unit on every report before comparing a home result with a Medellín one.

How AFC works as a test

AFC counts the antral follicles measuring roughly 2 to 10 mm, using a transvaginal scan in the early follicular phase, the first days after a period starts. ASRM considers AFC a reasonable alternative to AMH when it is performed in an experienced center, and notes that it varies little from cycle to cycle (ASRM, 2020).

The weak point is that a person does the counting. Image quality, the position of the ovaries, cysts and technique can all affect the number. If a home scan and a Medellín scan disagree, it is reasonable to ask whether the difference changes anything or is simply measurement noise.

What these tests predict, and what they do not

This is where most confusion starts, often because a single number arrived without context. The table summarises ASRM's 2020 committee opinion.

The reason is that quantity and quality are different things. The UK regulator explains that fertility falls with age because both the number and the quality of eggs decline (HFEA). AMH and AFC track the first of those much better than the second. A younger patient with a low AMH may get fewer eggs per retrieval; that is not the same prognosis as an older patient with an average AMH.

When AMH and AFC disagree

They often do. ASRM cites a study in which the two markers were discordant in up to 30% of cases (ASRM, 2020). A mismatched pair does not mean a laboratory made a mistake. It means the physician needs to weigh both results alongside your age and any earlier treatment.

If you have done an IVF or egg-freezing cycle before, your actual response is important evidence: how many follicles grew, on what dose, and how many eggs were retrieved. ASRM's criteria for predicting poor response count a previous poor response alongside age and an abnormal reserve test, and two previous poor responses are enough on their own (ASRM, 2020). Send those cycle records with your lab results.

What a very low result means

A very low AMH changes the conversation but should not end it. ASRM summarises data from more than 5,000 fresh IVF cycles in patients with AMH below 0.16 ng/mL: 54% of cycles were cancelled, about half produced three or fewer eggs, and a quarter had no embryo to transfer. The live-birth rate was still 9.5% per cycle started (ASRM, 2020). ASRM's position is that extremely low AMH should be used to counsel patients about a likely limited response, not as a reason to refuse IVF.

For someone flying to Colombia, those figures are planning figures. A high chance of cancellation means you need a changeable ticket, a written policy on what you pay if stimulation stops early, and an honest discussion about whether one retrieval is realistic. Our guide to how many IVF cycles you might need covers how to think about that sequence.

What a high result means

A high count is not simply good news. ASRM lists an AFC above 24 and an AMH above 3.4 ng/mL among the baseline risk factors for ovarian hyperstimulation syndrome (OHSS), while warning that AMH thresholds depend on the assay (ASRM, 2023). High markers are common in polycystic ovary syndrome, which ASRM now also calls polyendocrine metabolic ovarian syndrome (PMOS). If that describes you, read PCOS, IVF and OHSS risk before agreeing to a protocol or a flight date.

If you are not trying to conceive yet

AMH is often sold as a general "fertility test". ASRM says ovarian reserve markers should not be used as a fertility test in people whose fertility is untested, and should not be used to promote planned egg freezing (ASRM, 2020). If you are weighing egg freezing, your age at freezing matters more; our egg freezing quote guide explains what to price.

Using your results to plan a Medellín cycle

Because AMH can be drawn on any day and AFC needs an early-cycle scan, both can often be done at home before you travel, if the Medellín clinic agrees to accept outside results. Ask that before paying for either test. Ask too what format the clinic needs: the full laboratory report with units and reference range, and a written AFC report that gives the count for each ovary. If you also plan to start monitoring at home, see whether IVF monitoring can start before you fly.

Then ask the question that matters most: what does this result change? Reasonable answers include the starting medication dose, the protocol, how long you are likely to stay in Medellín, whether embryos will probably be frozen rather than transferred fresh, and whether more than one retrieval should be budgeted. ASRM's 2023 guideline recommends individualised gonadotropin dosing based on ovarian reserve testing, so your numbers should visibly shape the plan rather than sit in a file (ASRM, 2023).

Medical disclaimer: MedellinIVF.co is an independent educational and lead-navigation site, not a fertility clinic. Nothing on this page is diagnosis, treatment advice or a guarantee of outcome. Prices and policies change. Verify current information directly with the treating clinic and appropriate Colombian registries.