PdG Test: Understanding Progesterone’s Role in Fertility
A PdG test checks levels of pregnanediol glucuronide (PdG), a hormone marker found in urine that reflects progesterone in the body. It’s one of the clearest ways to confirm if ovulation has really happened — essential information if you’re trying to conceive.
Author
Tassia O’Callaghan
Reviewed by
Kayleigh Hartigan
14 min read
Published 24 October 2025
Spotlight:
- PdG (pregnanediol glucuronide) is a urine metabolite of progesterone, the hormone that supports ovulation and early pregnancy.
- Testing PdG confirms ovulation more reliably than LH strips alone.
- At-home PdG test strips make it simple to track your fertility window and luteal phase.
- Low PdG levels may signal issues with ovulation or luteal phase deficiency.
- Results guide next steps, from timed intercourse to speaking with a GP or fertility clinic.
What is PdG testing?
PdG stands for pregnanediol glucuronide, a substance your body produces when it breaks down progesterone. Since progesterone is the hormone that rises after ovulation, finding PdG in urine is a reliable way to check whether ovulation really happened. [1,2]
It’s important to note that PdG is not progesterone, but is an indicator of progesterone. For a more accurate progesterone test, you’ll need to visit a fertility clinic, your GP, or carry out an at-home progesterone blood test, sending your blood draw to a lab for the results.
Unlike LH (luteinising hormone) tests, which only predict that ovulation might occur, PdG testing confirms it actually did. That difference matters if you’ve been trying to conceive for a while and want more clarity on whether your cycle is progressing as expected. [3]
At-home PdG test strips (sometimes called at-home progesterone tests) make this process straightforward. By testing your urine in the days after suspected ovulation, you can see whether your body is producing enough progesterone to support the second half of your cycle — the luteal phase — which is crucial for implantation and early pregnancy.
Who are PdG tests for?
PdG testing can be helpful if you’re trying to conceive and want more certainty about what’s happening in your cycle. It goes beyond prediction to show whether your body has produced enough progesterone after ovulation — giving you insight that can be reassuring, and sometimes eye-opening.
- For those with irregular cycles or PCOS, it can confirm whether ovulation is actually happening, even when cycle patterns are hard to track.
- If you’ve been told you have unexplained infertility, PdG results may uncover details that standard tests have missed.
- After an early pregnancy loss, PdG can shed light on whether your luteal phase is providing the hormonal support an early pregnancy needs.
- If you’re preparing for or going through fertility treatment, like IVF or IUI, PdG testing offers an extra layer of information, helping you and your doctor make decisions with more confidence.
Fertility Test: What It Is, What It Costs, and What It Tells You
From hormone checks to sperm analysis, we break down the most common fertility tests — plus where to get tested and how to understand your results.
How is PdG tested?
PdG testing is usually a simple, at-home process. Test strips are designed to measure PdG in urine, offering a clear view of what’s happening hormonally after ovulation. For the most reliable results, it’s recommended to use your first morning urine, when hormone levels are most concentrated.
You’ll either dip the strip directly into a sample or place a few drops onto the test window, then wait for the result to appear. Each brand provides its own reference guide, so you can compare your outcome against the expected range after ovulation.
For those who want more detail, digital fertility monitors can track exact PdG concentrations and sync results to an app, creating a fuller picture of your luteal phase across several days or cycles.
While at-home tests give you valuable insights, they can’t always explain the bigger picture. If your PdG results seem inconsistent, or you’re unsure how they relate to your fertility path, it’s important to share them with a fertility doctor. A specialist can interpret your results alongside blood work, ultrasounds, and other tests, helping you understand whether further support is needed.
When to take a PdG test to confirm ovulation?
The best time to take a PdG test is just after your LH surge — the point when ovulation is about to happen. While a blood test for progesterone is usually scheduled around 7 days past ovulation (7 DPO), PdG urine testing allows you to start sooner and see the hormone shift as it happens. [4]
Most at-home PdG kits suggest testing from the day of your positive LH strip, then continuing daily for several days. What you’re looking for is a clear, sustained rise in PdG across the mid-luteal phase, which shows ovulation has occurred and progesterone is being produced at the right time.
Many digital monitors and fertility apps (like Mira or Proov Insight) help by automatically logging your LH and PdG results. They highlight your “peak fertility” day based on the LH surge, then guide you to track PdG over the following week. This means you’re not guessing when to test — the app prompts you, and your results are stored in a cycle chart you can compare month by month or share with a doctor if needed.
What urine to use for a PdG test?
For the most accurate results, PdG tests should be done with first morning urine. This is when hormone levels are most concentrated, reducing the chance of a false negative. Research shows that using consistent early-morning samples, collected in a container rather than midstream, improves the reliability of results — especially when tracking changes over several days. [4]
How long should you test for a PdG?
PdG testing usually begins from the day of your LH peak — when ovulation is expected — and continues through the second half of your cycle. You’ll often see a meaningful rise around 7 days past ovulation (7 DPO), but many people choose to keep testing until the day their next period is due. [4]
Tracking across this whole window helps you see not just whether PdG rose, but also whether it stayed elevated for long enough to support implantation. If your period arrives, PdG will naturally fall. If you do conceive, PdG typically remains high — though it’s important to remember that PdG tests are not pregnancy tests. Only an hCG test (a pregnancy test) can confirm pregnancy. [5]
Why do I need to do a PdG test?
PdG testing isn’t an essential part of fertility care — many people conceive without ever checking their progesterone levels. But for some, it can provide a layer of insight that makes the process feel clearer and more informed. By confirming whether progesterone has risen after ovulation, PdG testing can help you understand what’s really happening in your cycle.
- Plan more precisely. Knowing when ovulation has truly happened helps you focus your efforts in the most fertile days of your cycle (your fertile window), reducing some of the guesswork.
- Track patterns over time. Repeated PdG testing across several cycles can highlight trends — for example, whether your luteal phase is consistently short, or if ovulation sometimes doesn’t occur.
- Guide next steps sooner. If results are consistently low or irregular, you’ll have evidence to bring to your GP or fertility specialist, which can shorten the time to further investigations or treatment.
- Support emotional reassurance. For many people, simply seeing proof that ovulation has occurred can help ease anxiety and restore a sense of control.
Can I ask my GP for a PdG test?
On the NHS, ovulation is usually confirmed with a day 21 blood test, which measures progesterone directly in your blood. While this is a well-established method, it assumes a textbook 28-day cycle with ovulation on day 14. If your cycle is longer, shorter, or unpredictable, that single blood draw can sometimes miss the true picture.
PdG testing isn’t something NHS clinics typically offer, which is why many people choose to use at-home tests alongside standard care. They give you the flexibility to test over several days, rather than relying on a one-off blood test, which can be especially valuable if you don’t ovulate at the same time each month.
That said, PdG testing isn’t a replacement for medical advice. If you’re struggling to conceive or have concerns about your cycle, sharing your PdG results with a GP or fertility doctor can help build a fuller understanding of your hormonal health. Used alongside blood tests, scans, and professional analysis, PdG can add another layer of insight to guide your next steps.
How much does a PdG test cost?
The cost of PdG testing varies depending on how much detail you’re looking for, and whether you prefer to test at home or through a clinic.
- At-home PdG test strips are the most affordable option, usually between £20–£30 per pack. These are designed for repeated use across a cycle, giving you flexibility without a big upfront cost.
- Digital fertility monitors (such as Mira or Inito) come with a higher initial price tag — around £150–£250 — but they provide more precise readings, track multiple hormones, and store results in an app. Keep in mind you’ll need to budget for ongoing refill wands or strips, which can cost around £40–£70 for 15–20, depending on the brand.
- Clinic-based progesterone testing tends to be charged per blood draw, usually £50–£150. This can add up if you need to test across multiple points in your cycle, but it does mean results are analysed directly by a medical team.
For many people, starting with at-home tests feels like a manageable first step, while others prefer the reassurance of having results recorded and interpreted in a clinic. Ultimately, the right option depends on your comfort level, budget, and how closely you want to monitor your cycles.
Understanding your PdG test results
PdG levels give you a window into what your body is doing after ovulation. A rise tells you that progesterone is being made — supporting the uterine lining and creating the right environment for implantation. If levels don’t rise, or if they fall too quickly, it may suggest ovulation hasn’t happened or that your luteal phase isn’t providing enough hormonal support.
It’s important to remember: one test on its own doesn’t give the full picture. What matters most is the pattern — a sustained rise in PdG over several days after ovulation. Still, knowing the average ranges can help you put your results into context. [6,7,8,9,10]
Cycle phase
Typical PdG range (µg/mL)
What it means
Follicular phase (before ovulation)
1–5
Low levels are expected. Your body isn’t producing much progesterone yet.
Ovulatory phase
3–7.5
A small rise may happen just as ovulation approaches, but this doesn’t confirm ovulation.
Luteal phase (after ovulation)
5–25
A clear, sustained rise shows ovulation has taken place and the corpus luteum is producing progesterone.
No rise after LH surge
<5
Suggests ovulation may not have occurred (anovulatory cycle).
Sustained high PdG (7–10 DPO and beyond)
>5 for at least 2–3 days
Indicates healthy ovulation and a supportive luteal phase for implantation.
Drop in PdG before period
Falls back to follicular levels
Signals the luteal phase has ended, and menstruation is about to start.
Continued PdG rise beyond 10 DPO
Rising above baseline luteal levels
Suggests pregnancy may be establishing, though only hCG testing confirms pregnancy.
When should a PdG test be positive?
A PdG test is expected to turn positive in the days after ovulation, once your body has started producing progesterone. For most people, that rise shows up between about 7–10 days past ovulation (DPO). What matters most isn’t just a single positive test, but seeing PdG stay elevated across several consecutive days — this pattern confirms that ovulation has taken place and that your luteal phase is being supported. [4]
What if the PdG never rises?
If PdG never rises, it often means ovulation didn’t happen that cycle, or that progesterone wasn’t produced strongly enough to support the luteal phase. Both can make conception harder but are relatively common. If this pattern continues across cycles, it’s worth sharing your results with a fertility doctor, who can confirm what’s happening through further tests and discuss treatment options like ovulation induction or progesterone support. [11]
Find the right clinic for you
Choosing a clinic is one of the biggest decisions you’ll make. We’ll find the best options for you and arrange your pre-treatment tests, empowering you from this point onwards.
How accurate is PdG testing?
Very — PdG testing is considered highly specific for confirming ovulation. Research shows that when PdG levels stay elevated for several days after a positive LH test, the chance of a “false positive” (suggesting ovulation when it didn’t happen) is close to zero. [4]
The sensitivity — how often the test correctly picks up ovulation — is a little lower, generally around 85–95%, depending on the protocol used. This means some cycles may show a false negative, even if ovulation occurred. [8]
Because PdG testing tracks hormone patterns over several days, it can give a broader picture of luteal phase health than a single blood draw. Still, the evidence base is small, and larger studies are needed before PdG tests are widely adopted in clinical care. For now, they can be a useful tool at home — especially if combined with professional input from a fertility doctor.
Are PdG tests worth it?
PdG tests aren’t essential for everyone, but they can be valuable for some people trying to conceive. If you’ve already been tracking ovulation with LH strips or cervical mucus, PdG adds an extra layer of reassurance that ovulation actually happened and that your progesterone is rising as expected. For those with irregular cycles, suspected luteal phase issues, or unexplained fertility struggles, PdG tracking can provide useful insights to discuss with a doctor.
That said, PdG testing is still relatively new, and evidence is limited compared with standard blood tests. It’s best seen as a supportive tool — not a replacement for medical assessment. If it gives you clarity, confidence, and better conversations with your doctor, it may be worth the investment.
PdG test FAQs
Does your PdG rise before ovulation?
No — PdG rises only after ovulation, as it’s a metabolite of progesterone released once the corpus luteum forms. If you notice a small bump in PdG before ovulation, it usually isn’t a true hormonal shift. The most common reason is concentrated urine (for example, if you’re dehydrated or testing after holding urine for a long time). A genuine PdG rise will be sustained across several days in the luteal phase, not just a one-off early blip.
Is PdG the same as hCG?
No — PdG and hCG are two completely different hormones. PdG (pregnanediol glucuronide) is a breakdown product of progesterone, used to confirm that ovulation has taken place. hCG (human chorionic gonadotropin) is the hormone that pregnancy tests detect, produced only once an embryo has implanted.
In short: PdG tells you if you’ve ovulated, hCG tells you if you’re pregnant. [1,2,12]
Can you ovulate without a PdG rising?
In most cases, ovulation and a PdG rise go hand in hand — but not always. Sometimes the follicle releases an egg but doesn’t produce enough progesterone afterwards, or the egg isn’t actually released despite the follicle luteinising (called a “luteinised unruptured follicle”). Both situations can look like ovulation happened, but PdG may stay low. If this pattern repeats, it’s a good idea to share your charts with a fertility doctor, since low or absent PdG after ovulation can point to luteal phase issues that may need support. [2,6,13,14,15]
Is a PdG test an ovulation test?
Not exactly. Ovulation predictor kits (OPKs) that measure LH are designed to forecast ovulation before it happens. A PdG test works differently — it confirms that ovulation has already taken place by detecting the progesterone metabolite in urine. Think of it this way: LH tests are the “heads up” that an egg is about to be released, while PdG tests are the “proof” that your body actually did ovulate and moved into the luteal phase. Both can be useful, but they serve different purposes in your fertility tracking toolkit.
Can you conceive with low PdG?
Low PdG in the luteal phase usually points to low progesterone activity — and since progesterone helps prepare the uterine lining for implantation, it can make conceiving more difficult. Research shows that cycles with sustained PdG above the 5 µg/mL threshold are far more likely to support implantation, while low mid-luteal PdG is linked with lower chances of pregnancy. That doesn’t mean conception is impossible with a lower rise, but it may explain why some cycles don’t progress, even when ovulation occurs. [8,10,15]
If you’ve noticed consistently low PdG results at home, it’s worth speaking to your GP or a fertility clinic. They can run serum progesterone tests, explore whether a luteal phase issue is at play, and, if needed, suggest treatments such as progesterone supplementation or tailored fertility support. The right investigations can give you a clearer picture and increase your chances of conception.
Sources
- National Library of Medicine, National Center for Biotechnology Information. Use of a Home-based PDG Urine Test to Confirm Ovulation. Last Update Posted 2018-03-20.
- Ecochard, R., Leiva, R., Bouchard, T., Boehringer, H., Direito, A., Mariani, A. and Fehring, R., 2013. Use of urinary pregnanediol 3-glucuronide to confirm ovulation. Steroids, 78(10), pp.1035-1040.
- NHS, South Tees Hospitals, NHS Foundation Trust. Luteinising hormone (LH). Page last updated: 27/04/2022.
- Bouchard TP, Fehring RJ, Schneider M. Pilot Evaluation of a New Urine Progesterone Test to Confirm Ovulation in Women Using a Fertility Monitor. Front Public Health. 2019 Jul 2;7:184. doi: 10.3389/fpubh.2019.00184. PMID: 31312631; PMCID: PMC6614355.
- Stavridis K, Balafoutas D, Kastora SL, Kalampokas T, Simopoulou M, Joukhadar R, Vlahos N. Urinary Pregnanediol-3-Glucuronide and Pregnancy Outcomes in Frozen Embryo Transfer Cycles: A Pilot Study. Cureus. 2025 May 8;17(5):e83709. doi: 10.7759/cureus.83709. PMID: 40486453; PMCID: PMC12144660.
- Leiva, R., McNamara-Kilian, M., Niezgoda, H., Ecochard, R. and Bouchard, T., 2019. Pilot observational prospective cohort study on the use of a novel home-based urinary pregnanediol 3-glucuronide (PDG) test to confirm ovulation when used as adjunct to fertility awareness methods (FAMs) stage 1. Bmj Open, 9(5), p.e028496.
- Journals, F. The Predictive Value of Urinary Progesterone Metabolite PdG Testing in Pregnancy Outcomes. https://doi.org/10.26502/OGR092
- National Institute for Health and Care Excellence. Proov Confirm for ovulation confirmation. Published: 6 June 2023.
- Reed BG, Carr BR. The Normal Menstrual Cycle and the Control of Ovulation. [Updated 2018 Aug 5]. In: Feingold KR, Ahmed SF, Anawalt B, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-.
- Wegrzynowicz AK, Beckley A, Eyvazzadeh A, Levy G, Park J, Klein J. Complete Cycle Mapping Using a Quantitative At-Home Hormone Monitoring System in Prediction of Fertile Days, Confirmation of Ovulation, and Screening for Ovulation Issues Preventing Conception. Medicina (Kaunas). 2022 Dec 15;58(12):1853. doi: 10.3390/medicina58121853. PMID: 36557055; PMCID: PMC9783738.
- Wegrzynowicz AK, Eyvazzadeh A, Beckley A. Current Ovulation and Luteal Phase Tracking Methods and Technologies for Fertility and Family Planning: A Review. Semin Reprod Med. 2024 Jun;42(2):100-111. doi: 10.1055/s-0044-1791190. Epub 2024 Sep 20. PMID: 39303740; PMCID: PMC11837971.
- NHS. Doing a pregnancy test. Page last reviewed: 9 February 2022.
- Koninckx, P.R. and Brosens, I.A., 1982. Clinical significance of the luteinized unruptured follicle syndrome as a cause of infertility. European Journal of Obstetrics & Gynecology and Reproductive Biology, 13(6), pp.355-368.
- Su HW, Yi YC, Wei TY, Chang TC, Cheng CM. Detection of ovulation, a review of currently available methods. Bioeng Transl Med. 2017 May 16;2(3):238-246. doi: 10.1002/btm2.10058. PMID: 29313033; PMCID: PMC5689497.
- Baird, D.D., Weinberg, C.R., Zhou, H., Kamel, F., McConnaughey, D.R., Kesner, J.S. and Wilcox, A.J., 1999. Preimplantation urinary hormone profiles and the probability of conception in healthy women. Fertility and sterility, 71(1), pp.40-49.