Fertility tests for women: what they measure and what the results mean

Trying to conceive · Updated July 2026 · All articles

Why fertility testing matters

Fertility tests do not tell you definitively whether you will conceive. What they do is give you and your medical team information about the specific factors that influence your chances: how many eggs you likely have left, whether you are ovulating, whether your tubes are open, and whether there are any structural issues in the uterus. This information shapes the advice you receive and the treatment you are offered.

Testing is usually initiated after a couple has been trying to conceive without success for 12 months (or 6 months if either partner is over 35). But if you have a known condition such as PCOS, endometriosis, irregular cycles or a history of pelvic infection, it is reasonable to ask for some basic tests earlier rather than waiting.

Different tests are arranged at different stages and by different specialists. Your GP can order many of the blood tests and refer you for an ultrasound. More invasive investigations such as a hysterosalpingogram (HSG) or laparoscopy are arranged by a gynaecologist or fertility specialist. Understanding what each test does helps you follow your results with confidence.

AMH: ovarian reserve and what it can tell you

Anti-Mullerian hormone (AMH) is produced by the small follicles in the ovaries and reflects the size of your remaining egg supply, known as ovarian reserve. A higher AMH suggests more eggs remaining; a lower AMH suggests fewer. Unlike most cycle-related hormones, AMH is relatively stable throughout the month and can be tested on any day.

It is important to understand what AMH does and does not measure. It reflects quantity, not quality. Someone with a low AMH may still produce a high-quality egg each month and conceive naturally. Someone with a high AMH is not guaranteed good egg quality. AMH is most useful for predicting how someone will respond to ovarian stimulation in IVF: people with low AMH tend to produce fewer eggs in response to medication, which affects cycle planning.

Reference ranges vary between laboratories, but broadly: above 15 to 20 pmol/L is considered a good reserve; 5 to 15 pmol/L is in the lower-normal range; below 5 pmol/L is considered low reserve. AMH declines naturally with age, so a result that looks low in your 30s may look different in context for your age group. Always ask your GP or specialist to explain your result relative to the expected range for your age.

Day 3 FSH and oestradiol

Follicle-stimulating hormone (FSH) is measured on day 2 or 3 of your menstrual cycle, when it should be at its monthly baseline. FSH stimulates follicle development in the ovaries. When ovarian reserve is declining, the pituitary gland produces more FSH in an attempt to drive the ovaries harder, so an elevated day 3 FSH is a signal of reduced reserve.

A day 3 FSH above 10 to 12 IU/L is generally considered elevated, though laboratory reference ranges vary. Oestradiol is measured at the same time: if oestradiol is unusually high on day 3, it can suppress FSH artificially and make an elevated FSH look falsely normal. This is why the two tests are usually requested together.

Like AMH, FSH is a marker of reserve rather than of egg quality or monthly fertility. Many people with elevated day 3 FSH conceive naturally. The test is most useful as part of a broader assessment rather than as a standalone verdict. Day 3 FSH can also fluctuate from cycle to cycle, so a single high reading is not as meaningful as a consistent pattern across two or three cycles.

Antral follicle count: the ultrasound view of your reserve

An antral follicle count (AFC) is performed via transvaginal ultrasound, typically early in the menstrual cycle. A sonographer counts the small resting follicles visible in both ovaries; these antral follicles are the pool from which the developing egg is drawn each month. The total number across both ovaries gives an estimate of ovarian reserve that correlates well with AMH.

A combined AFC of 10 to 20 is generally considered normal for a woman in her late 20s to mid-30s, though reference ranges vary with age. Fewer than 5 to 7 antral follicles total is considered a low count. A high AFC (over 25 to 30) may point towards PCOS.

The AFC is a direct visual measurement rather than a blood test marker, which some people find useful. It is performed as part of a baseline scan before IVF, and may also be done as part of a general fertility work-up. The count can vary somewhat between cycles and between operators, so it is most meaningful when interpreted alongside AMH and FSH rather than in isolation.

Day 21 progesterone: confirming ovulation

A blood progesterone level measured around day 21 of a 28-day cycle (or approximately 7 days after expected ovulation in a longer cycle) is one of the simplest and most informative fertility tests. After ovulation, the ruptured follicle becomes the corpus luteum, which produces progesterone. A level of 16 nmol/L or above is generally considered consistent with ovulation having occurred.

If your cycle is longer than 28 days, the Day 21 progesterone test needs to be timed differently: roughly 7 days before your expected next period rather than literally on day 21. A GP who orders this test on day 21 regardless of cycle length may miss the progesterone peak entirely if ovulation is late. Make sure the timing is appropriate for your cycle.

A low progesterone result does not always mean you are not ovulating; it could mean the test was done at the wrong time in your cycle, or that you have a luteal phase defect where ovulation occurs but the corpus luteum does not produce adequate progesterone to support implantation. Your GP or specialist can advise on whether repeat testing or further investigation is warranted.

Hysterosalpingogram: checking the tubes

A hysterosalpingogram (HSG) is an X-ray procedure used to check whether the fallopian tubes are open and to assess the shape of the uterine cavity. A small catheter is passed through the cervix and a contrast dye is injected, which fills the uterus and (if tubes are open) spills into the pelvic cavity. The pathway is captured on X-ray.

Blocked fallopian tubes are one of the main treatable causes of infertility, and an HSG is the standard first-line test for tubal patency. The procedure takes around 15 to 30 minutes and is done in a radiology or gynaecology department. Most people experience cramping during the injection of dye, which can range from mild to moderate. Taking ibuprofen an hour before the procedure is usually recommended.

If the HSG suggests a problem, the next step is usually a laparoscopy for direct visualisation and, if appropriate, treatment. It is worth knowing that HSG can occasionally produce false positives (suggesting a blockage that is actually due to spasm rather than a true block); a gynaecologist will interpret the findings in context and advise on next steps.

Laparoscopy: the definitive look

Laparoscopy is a minimally invasive surgical procedure performed under general anaesthetic in which a small camera is inserted into the abdomen to directly visualise the pelvis. It is the gold standard investigation for endometriosis, pelvic adhesions and other structural conditions that cannot be assessed by ultrasound or HSG alone.

Laparoscopy is not usually the first investigation requested; it follows on from simpler tests that have raised a specific concern, or when all standard tests are normal and a cause is still being sought. It can be both diagnostic and therapeutic: if endometriosis or adhesions are found, the surgeon can treat them during the same procedure.

The procedure requires a day-case admission and recovery of a few days. There are small risks associated with any surgical procedure, so laparoscopy tends to be reserved for cases where a specific surgical diagnosis is suspected or where other investigations have been inconclusive.

What your results mean in context

Individual test results mean very little in isolation. A single low AMH, a slightly elevated FSH or an equivocal progesterone level needs to be interpreted alongside your age, cycle pattern, how long you have been trying, any relevant medical history and the results of other tests. Receiving a result without context can cause unnecessary anxiety or false reassurance.

It is always worth asking your GP or specialist to explain what a result means for your specific situation rather than comparing it to a generic normal range online. Reference ranges vary between laboratories, and whether a given result is clinically significant depends heavily on the full picture.

If you feel results are being dismissed or not fully explained, you are entitled to ask for clarification or a referral to a specialist who can review the whole picture. A fertility specialist or reproductive endocrinologist can offer a more detailed interpretation than a GP, and most will welcome direct questions about what each result means for your treatment options and prognosis.

Frequently asked questions

What is AMH and why does it matter?

Anti-Mullerian hormone (AMH) is produced by small follicles in the ovaries and reflects the size of your remaining egg supply. It does not tell you about egg quality or your monthly chance of conceiving naturally, but it gives fertility specialists a sense of how you are likely to respond to ovarian stimulation in IVF. It can be measured on any day of the cycle.

What is a normal AMH level?

Reference ranges vary between laboratories, but broadly: above 15 to 20 pmol/L is considered a good reserve; 5 to 15 pmol/L is in the lower-normal range; below 5 pmol/L is considered low. AMH declines naturally with age, so results need to be interpreted in the context of your age and circumstances.

Does a low AMH mean I cannot conceive naturally?

No. AMH reflects the quantity of your remaining egg supply, not the quality of eggs being released each month. Many people with low AMH conceive naturally. AMH is most useful for predicting IVF response, not for predicting natural conception rates.

What does a high Day 3 FSH mean?

Elevated FSH at the start of the cycle suggests the pituitary is working harder to stimulate the ovaries, which can indicate reduced ovarian reserve. A level above 10 to 12 IU/L at baseline is generally considered elevated, though reference ranges vary between laboratories. It should be interpreted alongside oestradiol and AMH.

How is an HSG done and does it hurt?

An HSG is an X-ray procedure in which contrast dye is injected through the cervix into the uterus and tubes. It takes around 15 to 30 minutes. Most people feel cramping during the procedure, ranging from mild to moderate. Taking an over-the-counter pain reliever beforehand is usually recommended.

Who arranges fertility tests?

Your GP can arrange blood tests including Day 3 FSH, oestradiol, AMH and Day 21 progesterone, and can refer you for a pelvic ultrasound. An HSG or laparoscopy is arranged by a gynaecologist or fertility specialist. If GP-level tests are normal and you are still not conceiving, a specialist referral is the appropriate next step.

This article is for general information only. If you have concerns about your fertility or reproductive health, speak to your GP or a fertility specialist.