Can You Really Test Your Fertility?
This is one of the most frequently asked questions I receive from clients.
And the honest answer? No.
There isn’t a single test that can definitively tell you how fertile you are or how likely you are to conceive. What we can do, however, is test various factors that affect your ability to conceive. If any of those markers are off, we know where to start and what might be get in the way of a smooth conception journey.
The biggest barriers for most people tend to be:
Not knowing which tests to ask for
Not knowing where to get them (the NHS can help if you know what to request)
Not knowing how to interpret the results when they land in your inbox
This blog is here to help break all that down.
A Word of Caution
I see so many people spending £600 to £700 on "fertility MOTs" from big clinics or companies, only to be told one thing: their AMH level. While AMH has its place, it’s just one piece of the puzzle. And it certainly doesn’t deserve to send you into a panic spiral (more on that below).
Also, try not to focus too much on whether your results are "normal". NHS ranges tend to be quite broad, and what we’re looking for is what’s optimal for conception.
How to Access These Tests
Most of the tests listed below can be done via your GP, especially if you're experiencing irregular cycles, heavy periods, PMS, fatigue or other hormonal symptoms. These are all legitimate gynaecological reasons for testing, and very relevant to fertility, even if you're not framing it that way. You can tell your GP you are trying to conceive and, if you have been trying for more than a year (this timescale varies depending on where you are in the UK, in some regions it’s now 2 years), they should do these investigations for you.
If you have private health insurance, the same principle applies. Many policies will cover testing and scans if they’re requested for gynaecological reasons, but not if they’re explicitly for fertility. It’s a frustrating technicality because the tests are identical, but wording matters when it comes to insurance. If you’re experiencing symptoms that affect your menstrual health (which most people trying to conceive are), it’s perfectly valid to pursue investigations through that route.
Either way, unfortunately, our healthcare system requires you to work hard to advocate for yourself. Most private doctors and GPs are happy to add one or two extra blood tests to your panel, but only if you ask for them! Make sure to speak up, and always request a copy of your bloods be sent to you so that you have them to hand in the future. I’ve written a checklist at the bottom of this page to take with you to the doctor so you don’t have to remember all this information.
What To Ask For and Why
Day 3 Bloods
Taken between days 2 and 5 of your cycle, this panel gives us a general sense of how your hormones are behaving at baseline.
LH (Luteinising Hormone)
LH helps trigger ovulation. It surges mid-cycle just before the egg is released.
High levels may indicate PCOS or perimenopause Low levels might point to stress, under-eating, or pituitary dysfunction
This LH surge is what ovulation strips/ Ovulation tester Kits, OTKs, detect (not if you are actually ovulating or not as this happens BEFORE ovulation). If you have PCOS, you may get constant false positives due to consistently raised LH. For more info on how to track your cycle, including ovulation test kits, see my article How to Track Your Ovulation
Optimal range: around 2.8 to 6 IU/mL (NHS range: 2.8 to 7.6)
FSH (Follicle Stimulating Hormone)
Stimulates the growth of follicles in the first half of your cycle.
High FSH is sometimes a sign of low ovarian reserve or perimenopause (IVF clinics often have a cut-off for FSH, particularly if AMH is also low)
Low FSH might suggest post-pill suppression, hypothalamic amenorrhoea, or pituitary issues
Oestrogen (Estradiol - E2)
Provides a baseline view of your circulating oestrogen.
High levels may relate to fibroids, endometriosis, or oestrogen dominance
Low levels are common post-pill or with high stress, under-eating, or over-exercising
Testosterone
Supports egg development, libido, energy, and mood.
High: Often seen in PCOS
Low: Can affect egg quality, energy, and libido
Day 21 Progesterone Test
This test checks whether ovulation has occurred.
Progesterone is released by the follicle after it releases the egg.
Ideally, levels should be over 30 nmol/L to confirm ovulation. The problem is that this test is almost always done on day 21, assuming a 28-day cycle. But if you ovulate later (as many women do), testing on day 21 might give a false low reading.
The other problem is that progesterone is released in constant little pulses, meaning the value on a blood test changes second by second. A better way to check if ovulation has occurred is looking at a BBT chart and looking for that consistent temperature range in the second half of the cycle), or via an ultrasound (more on imaging below).
Track your ovulation (e.g. with basal body temp or LH strips), and do this blood test 7-10 days after ovulation, whatever day that lands on for you.
If progesterone is low, it’s worth checking other factors like thyroid health, iron, vitamin B6, and overall stress or energy output.
Thyroid Health and Fertility
This is probably the most under-tested but essential area in fertility screening. Most GPs will only check TSH, or Thyroid Stimulating Hormone. This is produced by the brain and tells the thyroid to produce hormones.
High TSH suggests an underactive thyroid (hypothyroidism) and low TSH may mean the thyroid is overactive (hyperthyroidism). Both of these can disrupt your cycle, reduce egg quality, affect ovulation, and increase miscarriage risk. They’re usually very treatable with medication, typically levothyroxine.
Symptoms to look out for include: Feeling cold all the time (or overheating easily), Fatigue or low energy, Unexplained weight gain or loss, Mood changes or anxiety, Hair loss or dry skin, Irregular or missing periods. If you mention any of the above symptoms to your GP and ask for a full thyroid panel they should do it without question!
Even if you don’t have symptoms, thyroid testing should be a standard part of any fertility investigation. Thyroid hormones fluctuate throughout life, especially around big hormonal events like pregnancy, postpartum, breastfeeding, menopause, and even coming off the pill.
What to ask for:
TSH Free T3 (the active hormone)
Free T4 (the stored hormone)
Reverse T3
Thyroid antibodies (TPO and Thyroglobulin) - These are often raised and, if so, can be a barrier to concieving. Sadly they are often only tested late after someone has been struggling to conceive for a while, so I always like to check these as part of a standard panel.
Androgens:
Androgens are typically labelled as "male" hormones, but women need them too — just in smaller amounts. They support libido, mood, energy, egg development, and ovulation.
Testosterone Helps with libido, follicular development, and egg quality - as seen above.
Androstenedione A precursor hormone that can convert into testosterone or oestrogen. Raised levels may contribute to acne, hair thinning, or unwanted facial hair.
DHEA-S (Dehydroepiandrosterone Sulphate) Made by the adrenal glands. High levels may be linked to PCOS or chronic stress. Low levels can indicate adrenal burnout or age-related decline.
AMH (Anti-Müllerian Hormone)
Measures ovarian reserve – the number of follicles left in your ovaries. A GP will test this if you’re seeing them for fertility reasons. Most private health insurance will not cover this test, as it really is only relevant to fertility (or more specifically, to IVF). This is also the main one that fertility companies will charge you a lot of money to test - there are some more accessible companies like Hertility which allows you to do AMH testing.
Please think before getting your AMH tested and remember these facts:
AMH does not predict your chances of natural conception month-to-month.
Low AMH is more relevant for IVF stimulation than natural fertility.
Levels can drop temporarily after pregnancy, miscarriage, or while breastfeeding, or even from a low vitamin D status.
High AMH may indicate PCOS.
This is often the test that causes the most panic — if this is you, read my blog post on AMH here.
Prolactin
High levels can suppress ovulation. Elevated in breastfeeding, but should be low if you're not nursing.
Can sometimes be elevated due to a benign pituitary tumour (e.g. prolactinoma) and needs further investigation.
Acupuncture can be helpful in naturally lowering prolactin levels.
Additional Blood Tests Worth Requesting
These nutrients directly affect ovulation, egg health, and implantation, but won’t be included in any standard gynae or fertility work up… unless, you ask for them!
Vitamin D
B12 - specifically ask for total B12, Active B12 (holo-TC), Homocysteine, and MMA.
Folate
Iron — aim for 11 to 22 µmol/L
Ferritin — aim for 157 to 337 pmol/L
Imaging: What Scans Can Show
Transvaginal Ultrasound
Offered via GP or gynaecologist for any standard work up (gynae or fertility related). This can detect (depending on when in your cycle you are being scanned):
Cysts/Polyps
Fibroids (though not always visible)
Signs of endometriosis (though not always visible)
Endometrial lining thickness (we want the lining to be at least 6-7mm thick before ovulation occurs for implantation to be able to occur) - if scanned around ovulation time. For more on lining thickness see my post here.
Whether ovulation has occurred (by presence of corpus luteum) - if scanned after ovulation has occurred
AFC (Antral Follicle Count) - how many small follicles are visible on your ovaries that month. IVF clinics use it to predict how you might respond to stimulation For natural conception, remember: you only need one follicle to release one good egg
Microbiome and Infection Screening
High Vaginal Swab
Done via GP/Gynae if you have irregular bleeding, discharge, or pain (but in my opinion should be done as a standard fertility workup - ask for one!). Can detect things like BV (bacterial vaginosis), thrush, ureaplasma, other bacterial imbalances - EVEN if you have no symptoms, and all which may be impacting fertility.
Vaginal Microbiome Test
A private only at home test (from providers like Invivo, Daye, Fertlysis, ScreenMe) that looks at vaginal flora. We want lactobacillus dominance for optimal fertility. For more information on the vaginal microbiome see here.
Uterine Microbiome Test
Looks at the uterine environment. Helpful if you’ve had failed IVF rounds or recurrent miscarriage. For more information on the Uterine Microbiome see here.
STI Screening
Always request this via your GP/gynaecologist. Silent infections like chlamydia or ureaplasma can go unnoticed but affect fertility.
Final Thoughts
Fertility isn’t a diagnosis. It’s a dynamic state. These tests are a helpful way to understand your body and its needs, but they are only part of the picture.
And remember: the woman is only half the story. Male testing is equally important, and it’s still far too often overlooked. I’ll be sharing a full breakdown of male fertility testing next week, so keep your eyes peeled.
I’ll also be publishing a separate guide for anyone who has experienced miscarriage or pregnancy loss, with deeper investigation options. That one’s coming soon too.
If you’re not sure where to begin or what your results mean, I offer 1:1 sessions to review your case and create a clear, step-by-step plan. Get in touch here to book your fertility review.
Checklist to Take to Your Doctor
Bring this list with you to your GP appointment or gynaecologist:
FSH (day 2-5 of cycle)
LH (day 2-5 of cycle)
Oestradiol (E2) (day 2-5 of cycle)
Testosterone
Androstenedione,
DHEA-S
Prolactin
AMH
Day 21 Progesterone (Done 7 days after ovulation, not necessarily on cycle day 21!)
Full Thyroid Panel including: TSH, Free T3, Free T4, Reverse T3, TPO antibodies, Thyroglobulin antibodies
Vitamin D
B12 and Active B12
Homocysteine
Iron and Ferritin
Folate
Infection & High Vaginal Swab / STI Panel
Imaging Transvaginal Pelvic Ultrasound and ask them to tell you your Antral Follicle Count (AFC), Endometrial Thickness & if they see anything abnormal (cysts, polyps, adenomyosis/fibroids etc)