AMH, FSH, LH: Your Ovarian Reserve Labs Explained

A number on a results screen has unsettled you. Maybe your AMH came back lower than you expected, or your day-3 FSH is sitting at the upper edge of the reference range, or the lab flagged your LH-to-FSH ratio. You want to know what your doctor actually sees in this panel before you walk back into that next appointment.

I am going to take you through AMH, FSH, and LH the way I take patients through them in clinic, with one core message running underneath: each of these hormones measures something different, none of them alone tells you whether you can get pregnant, and the panel is most useful when it is read together. The primary search people land on this with is amh test charges, but the more important question is what the result will and will not change.

What do AMH, FSH, and LH actually do?

Your menstrual cycle is run by a conversation between the brain (hypothalamus and pituitary) and the ovaries. The day-3 ovarian reserve panel intercepts that conversation in three places.

Follicle-stimulating hormone (FSH) is a pituitary hormone that recruits a cohort of small antral follicles at the start of each cycle. The early-follicular value, drawn cycle day 2 to 5, tells us how much the pituitary is having to "shout" to get a follicle going. A higher FSH usually means the ovary is harder to wake up. A lower FSH can mean the ovary is responsive, or it can mean the pituitary itself is being suppressed by something upstream.

Luteinizing hormone (LH) is the second pituitary hormone in the duet. Its mid-cycle surge is what triggers ovulation when a dominant follicle matures. The day-3 baseline value is less useful in isolation; what matters is the LH:FSH ratio and the broader pattern.

Anti-Müllerian hormone (AMH) is produced by the granulosa cells of small growing follicles. Serum AMH correlates closely with the antral follicle count seen on transvaginal ultrasound, so it gives us an estimate of the size of the recruitable pool.⁴ Think of FSH as the demand side ("how loud do I need to shout") and AMH as the supply side ("how many follicles are listening").

Together, the FSH, LH, and AMH triad is the standard fsh and lh blood test plus AMH that reproductive medicine has used for two decades to bucket the ovary into broad categories: responsive, diminished, hyper-responsive, or quietly suppressed.

What does AMH actually measure (and what can't it tell you)?

This is the lab that scares people most, partly because of how direct-to-consumer testing has marketed it. So I want to be precise.

AMH correlates with antral follicle count with an r around 0.7 to 0.8 in most studies, which makes it the best blood marker we have for the size of the small-follicle pool.⁴ It is excellent at predicting how an ovary will respond to controlled ovarian stimulation in IVF. A high AMH flags hyperresponse and the risk of ovarian hyperstimulation syndrome. A low AMH flags poor response and helps an RE individualise the stimulation protocol.³

What AMH does not do is predict natural fertility well. The Steiner 2017 JAMA cohort followed women in their 30s and early 40s who were trying to conceive without treatment and measured AMH and FSH alongside time to pregnancy.¹ The pivotal finding: AMH did not predict the probability of conceiving within twelve cycles. A woman with a low AMH for her age had the same per-cycle chance as a woman with a normal AMH. The 2020 ASRM committee opinion on ovarian reserve testing explicitly states that AMH should not be used to counsel a person without infertility about her natural conception chances.² I say this in clinic almost every week.

Some practical points that get missed:

• Cycle-day independence: AMH is relatively stable across the menstrual cycle. You can draw it on any day, which makes it useful for people with irregular PCOS cycles who cannot reliably hit cycle day 3.
• Assay variability: AMH values vary between laboratories and assays. Roche Elecsys, Beckman Access, and Ansh Labs picoAMH each have their own calibration. If you are following AMH serially over time, ask whether the same assay was used each time. Comparing across assays is comparing across rulers with different markings.
• Units: AMH is reported as ng/mL in the US and increasingly pmol/L in Europe and the UK. The conversion is 1 ng/mL is approximately 7.14 pmol/L. An AMH of 1.0 ng/mL is roughly 7.1 pmol/L.
• Things that lower AMH transiently or chronically: Hormonal contraception, recent GnRH analogue use, recent ovarian surgery (especially cystectomy), high BMI, and chemotherapy can all suppress measured AMH. A single low number from a person on a combined oral contraceptive is not a verdict.
• AMH in PCOS: AMH is typically high in PCOS because the small antral follicle pool is enlarged. The 2023 International Evidence-Based Guideline now allows AMH to substitute for ultrasound antral follicle count in adult Rotterdam-criteria diagnosis when ultrasound is not available, with thresholds that depend on the assay.⁶ But AMH variability in PCOS is real. The same person can produce different AMH values across the year, especially after weight change or starting metformin. I do not chase small movements in AMH for PCOS patients who are otherwise stable.

If you are searching ovarian reserve amh test or amh test price, the cost in most private labs in the UK and US sits between £40 and £120, or roughly the same in dollars; the NHS will run it when clinically indicated but does not screen the general population. The cost is the easy part. What you do with the result is the hard part.

What does a day-3 FSH test tell you?

FSH is the older of the two reserve markers and is still informative, particularly when paired with estradiol. The fsh blood test results explained the way I explain it:

• Drawn on cycle day 2, 3, 4, or 5, ideally with estradiol on the same sample.
• A normal early-follicular FSH sits below roughly 10 IU/L in most labs.
• An FSH between 10 and 15 IU/L is consistent with diminished ovarian reserve.
• An FSH above 15 to 20 IU/L on repeated draws, in the right age and history context, is consistent with primary ovarian insufficiency.⁷
• A suppressed FSH (below 4 IU/L) with low LH and low estradiol, in someone not on hormonal contraception, suggests the pituitary itself is being held down. The most common causes are functional hypothalamic amenorrhea (low BMI, very high training volume, severe psychological stress) and, much more rarely, a pituitary lesion.

Two practical notes that catch people out. First, single-cycle FSH is noisy. The value can vary 30 to 40 percent between cycles in the same woman. So an FSH of 12 in one cycle and 8 in the next is not contradictory; it is biology. We act on trends and on the combined picture, not on one number. Second, estradiol matters. If a follicle has already taken off by the time the day-3 draw happens, the rising estradiol from that follicle suppresses the pituitary's FSH output and gives a falsely reassuring reading. A "normal FSH with high estradiol on day 3," with estradiol above roughly 60 to 80 pg/mL, is functionally an abnormal result, and a good RE will note that and consider repeating.

This is one of the reasons I often prefer AMH over FSH for first-pass ovarian reserve assessment, particularly in people with irregular cycles where day-3 is hard to pin down. But when planning IVF specifically, both values together (with antral follicle count on ultrasound) give the most stable picture.³

When does LH and the LH:FSH ratio matter?

The baseline day-3 LH is rarely interpreted alone. It earns its keep in two settings.

The first is PCOS pattern recognition. In lean PCOS, the day-3 LH is often elevated relative to FSH, with an LH:FSH ratio greater than 2. This is not part of the formal Rotterdam criteria, but it supports the clinical picture when oligo-anovulation and hyperandrogenism are also present.⁶ In PCOS with high BMI, the ratio is often blunted and may look normal even when classic features are obvious. So a normal LH:FSH does not exclude PCOS, especially in patients with higher BMI.

The second is detecting hypothalamic suppression. When LH, FSH, and estradiol are all low together in someone who is not on contraception, the pattern points away from the ovary and toward the brain. This is the picture of functional hypothalamic amenorrhea, which is far more common than people realise and which responds to lifestyle change rather than ovulation induction.

The other use of LH, mid-cycle surge tracking on urine ovulation predictor kits or serum LH, is a separate question. That is not what the day-3 panel is doing. If you are searching fsh and lh test because you have heard the names together, this distinction is worth holding.

Why is estradiol drawn with your day-3 FSH?

Every time I order day-3 FSH I order estradiol with it. The estradiol number is what makes the FSH number interpretable.

An estradiol above 60 to 80 pg/mL on day 3 means a follicle has already begun cohort selection earlier than expected. Its estrogen output suppresses pituitary FSH, which makes the FSH look low. In someone with diminished ovarian reserve this is exactly the pattern that produces a deceptively "normal" FSH on a single draw. Outside the day-3 window, estradiol means something different and is interpreted in the context of cycle phase.

If your panel does not include estradiol with FSH, that is worth flagging at your next appointment.

What do the common ovarian reserve panel patterns mean?

Reading the panel as a whole is where the work actually happens. A few patterns come up repeatedly in clinic.

Low AMH, high day-3 FSH, low antral follicle count on ultrasound: this is diminished ovarian reserve. The quantity of the recruitable pool is reduced. This does not mean egg quality is uniformly worse, and it does not mean you cannot conceive naturally, but it does shorten the window in which IVF is likely to be productive if you ever need it. The decision conversation usually becomes about timing, not about feasibility.

High AMH, raised LH:FSH ratio, many antral follicles on ultrasound, irregular cycles: this is the PCOS picture, and the 2023 International Evidence-Based Guideline for PCOS gives the diagnostic framework.⁶ If this is you, the supporting work on how PCOS is diagnosed and the full PCOS blood test panel covers the next step.

Low AMH, low FSH, low LH, low estradiol: this is hypothalamic suppression more often than ovarian failure. The differential is functional hypothalamic amenorrhea (energy availability, training load, stress) and, less commonly, pituitary causes. Treating this as diminished ovarian reserve and going straight to IVF stimulation can miss a reversible problem.

Normal AMH, normal FSH, normal LH, and still not ovulating: this pattern points us elsewhere. Thyroid, prolactin, weight change, recent contraception cessation, and stress all sit on this differential. The next posts in this cluster, on thyroid and fertility and prolactin and fertility, cover those.

What do these numbers not tell you?

I want to spend a paragraph on this because it is the part patients most often need to hear twice.

Your AMH does not tell you whether you can conceive this cycle. Your FSH does not predict miscarriage. Neither value predicts egg quality directly; they tell us about quantity (AMH and antral follicle count) and recruitment effort (FSH). A low AMH at 32 does not mean you cannot conceive naturally. It means that if you ever need IVF, the response window may be smaller than someone with a higher value, and that earlier discussion with an RE is reasonable. It does not move the natural-conception probability per cycle in a way Steiner 2017 could detect.¹

The corollary is also true. A normal AMH at 38 does not guarantee anything. Age is still the dominant variable for natural conception probability, mostly through egg quality (which our blood markers do not measure well), and the panel is one input among many.

When should you get AMH and FSH testing, and what does it cost?

If you are searching when to do amh and fsh test or amh test charges, the practical answer:

• AMH can be drawn on any day of the cycle. No need to wait.
• FSH and LH are most useful on cycle day 2 to 5, with estradiol on the same draw.
• For someone with regular cycles trying for under twelve months and under 35, I do not routinely order these labs. The information rarely changes the plan and the numbers often scare people for no medical reason.
• For someone aged 35 or older trying for six months, with PCOS or known irregular cycles at any age, with a history suggestive of diminished reserve (chemotherapy, ovarian surgery, family history of early menopause), or planning IVF, the labs earn their place.

I do not order AMH on a healthy 28-year-old with regular cycles unless we are planning IVF. It tells us less than it costs in worry.

How do AMH assays and unit conversions affect your result?

If you are moving between labs or comparing your result to a friend's, three things to check:

• Assay: Roche Elecsys, Beckman Access, Ansh Labs picoAMH, and Beckman Gen II all give slightly different numbers for the same sample. Use the same lab for serial values.⁴
• Units: AMH in ng/mL (US) versus pmol/L (UK, EU): multiply ng/mL by 7.14 to get pmol/L.
• Reference range: The lab's lab-specific reference range for your age band is what matters, not a generic "normal."

What to ask before your next appointment

A short list, in plain language:

1. Which lab and which assay ran my AMH, and what is their lab-specific range for my age band?
2. Was estradiol drawn with my day-3 FSH?
3. Given the panel as a whole, are you placing me in a PCOS, diminished-reserve, hypothalamic, or unexplained bucket?
4. Do any of these values need to be repeated in a different cycle?
5. Does this panel change your first-line treatment recommendation, or is the next step the same regardless?

These are the questions that move the visit from "I have a number that frightens me" to "here is what we are doing about it."

What if your ovarian reserve numbers are very low?

I want to end where the lab result landed you.

A single low AMH is not a verdict. If a value seems wildly out of context with your cycle history and clinical picture, repeating it in four to six weeks at the same lab is reasonable. Hormonal contraception within the past three months can suppress it. So can recent ovarian surgery.

Many people with AMH below 1 ng/mL conceive naturally. The Steiner 2017 finding holds firm on this point.¹ What changes with confirmed diminished ovarian reserve is the urgency conversation, not the possibility conversation. Earlier discussion of IUI and IVF, not "you cannot have a baby."

If diminished ovarian reserve is confirmed, the choice architecture shifts toward not delaying. That is a real change. But the lab does not make that decision for you. Your RE, your partner, your timing, and your context do.

What's next

• If labs suggest a PCOS picture: how PCOS is diagnosed by Rotterdam criteria and the full PCOS blood test panel
• If labs suggest diminished ovarian reserve: discuss timing with the how to choose a reproductive endocrinologist guide
• If labs are normal and you are still not ovulating: thyroid and fertility and prolactin and fertility
• If you are stepping toward IVF planning: the IVF section hub

Sources

1. Steiner AZ, Pritchard D, Stanczyk FZ, Kesner JS, Meadows JW, Herring AH, Baird DD. Association Between Biomarkers of Ovarian Reserve and Infertility Among Older Women of Reproductive Age. JAMA 2017;318(14):1367–1376. https://doi.org/10.1001/jama.2017.14588
2. Practice Committee of the American Society for Reproductive Medicine. Testing and interpreting measures of ovarian reserve: a committee opinion. Fertility and Sterility 2020;114(6):1151–1157. https://doi.org/10.1016/j.fertnstert.2020.09.134
3. La Marca A, Sunkara SK. Individualization of controlled ovarian stimulation in IVF using ovarian reserve markers: from theory to practice. Human Reproduction Update 2014;20(1):124–140. https://doi.org/10.1093/humupd/dmt037
4. Iliodromiti S, Anderson RA, Nelson SM. Technical and performance characteristics of anti-Müllerian hormone and antral follicle count as biomarkers of ovarian response. Human Reproduction Update 2015;21(6):698–710. https://doi.org/10.1093/humupd/dmu062
5. Broer SL, Broekmans FJM, Laven JSE, Fauser BCJM. Anti-Müllerian hormone: ovarian reserve testing and its potential clinical implications. Human Reproduction Update 2014;20(5):688–701. https://doi.org/10.1093/humupd/dmu020
6. Teede HJ, Tay CT, Laven JJE, Dokras A, Moran LJ, Piltonen TT, et al. Recommendations from the 2023 International Evidence-Based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Fertility and Sterility 2023;120(4):767–793. https://doi.org/10.1016/j.fertnstert.2023.07.025
7. Nelson LM. Primary Ovarian Insufficiency. New England Journal of Medicine 2009;360(6):606–614. https://doi.org/10.1056/NEJMcp0808697