By Adrian Stone, BHSc (Nutritional Medicine), BHSc (Naturopathy), Living Holistic Health — egg quality is shaped mostly by age and partly by things you can change, and AMH and CoQ10 each tell only part of that story.
Egg quality might be the most searched and least understood idea in fertility. It gets blamed for everything, sold as fixable in a fortnight, and measured with a blood test that doesn’t actually measure it.
So let’s slow it down. In this post I’ll explain what egg quality really means, what shapes it, what an AMH result can and can’t tell you, and what the CoQ10 trials actually found. This is part two of our Preconception Essentials series.
The short version:
- Age is the biggest driver of egg quality, mostly through chromosomes.
- AMH reflects egg quantity, not quality. In a large study, low AMH didn’t lower natural conception rates.
- Antioxidant trials in IVF show higher pregnancy rates, but no clear effect on live birth yet.
- Changes take around three months to show, because that’s how long a follicle takes to mature.
What Is Egg Quality?
Egg quality describes how likely an egg is to be fertilised, develop into a healthy embryo and implant. Two things matter most. The first is whether the egg carries the right number of chromosomes. The second is whether it has the energy, largely from its mitochondria, to complete the demanding work of maturing and dividing.
Chromosomes are where age shows up most clearly. According to PubMed, a study of 15,169 embryo biopsies found the lowest rate of chromosomal errors between ages 26 and 30. After that, errors rose predictably with age. The chance of a woman having no chromosomally normal embryo in an IVF cycle was 2% to 6% between 26 and 37, then 33% at 42 and 53% at 44.
That’s the honest starting point. Age is the single biggest driver of egg quality, and nothing in a supplement aisle reverses it. However, age isn’t the only factor, and that’s where the rest of this post comes in.
What Affects Egg Quality, and What Can You Change?
Beyond age, egg quality appears to be influenced by oxidative stress, smoking, body weight, overall diet and some environmental exposures. You can’t change your age, but you can change several of these. The research is stronger for some of them than others, and none of it promises a particular result.
Oxidative stress is one of the four root drivers I look for in almost every person I see. In simple terms, it’s an imbalance between the reactive molecules our cells produce and our capacity to neutralise them. Eggs are especially exposed, because maturing them takes a lot of energy. Is oxidative stress a proven cause of poor egg quality? Not yet. It’s a well-supported working hypothesis, and that distinction matters.
Timing matters too. The follicle that eventually releases an egg begins its final growth phase around 85 days before ovulation. Consequently, the changes you make now are likely to affect the eggs you release in roughly three months, not next cycle.
In practice, the modifiable list looks familiar: stop smoking, eat a Mediterranean-style diet, move regularly and aim for a healthy weight. The Preconception Essentials pillar post covers the evidence on each.
What Do AMH Levels Actually Tell You?
AMH, or anti-Müllerian hormone, reflects how many follicles are growing in the ovaries. In other words, it’s a marker of egg quantity, not egg quality. It’s genuinely useful for predicting how the ovaries will respond to IVF stimulation. It’s much less useful for predicting whether you’ll fall pregnant.
According to PubMed, an analysis pooling data from 28 studies and 5,705 women having IVF found AMH predicted a poor response to stimulation well. However, it added nothing to age when predicting ongoing pregnancy. That’s why fertility specialists use AMH to plan IVF medication, not to forecast success.
AMH also moves with things other than egg supply. A 2024 systematic review of 65 studies found higher BMI, smoking and the contraceptive pill were all linked with lower AMH. Current pill use was associated with readings roughly 17% to 31% lower. So a single low result taken while on the pill can look worse than the underlying picture.
At the other end, a high AMH can be a feature of PMOS (previously called PCOS). The 2023 international PCOS guideline now lets a raised AMH in adults stand in for an ultrasound finding for one of its diagnostic features.
AMH is most often ordered through your GP or fertility specialist, and it can also be arranged privately. Either way, we can help you make sense of your result alongside your age, your history and any other results.
As someone who’s been through IVF myself, I know how much weight that one number can carry. It’s worth knowing what it can and can’t say before you let it set the mood for the next six months.
Does Low AMH Mean You Can’t Get Pregnant Naturally?
Not on its own. In a well-known study on this question, women aged 30 to 44 with low AMH conceived naturally at much the same rate as women with normal AMH. Low AMH can matter for IVF planning and may hint at an earlier window. Still, it isn’t a verdict on natural conception.
According to PubMed, that 2017 JAMA study followed 750 women without a history of infertility who had just started trying. Women with low AMH (below 0.7 ng/mL) had a 65% chance of conceiving within six cycles, compared with 62% for women with normal values. By twelve cycles, the figures were 84% and 75%.
There are limits, of course. Only 84 women were in the low group, and the study says nothing about extremely low values or women already diagnosed with infertility. In short, it’s reassuring, but it’s not a guarantee.
Does CoQ10 Improve Egg Quality?
CoQ10 is the most studied antioxidant for egg quality, and the signal is promising but incomplete. In women having IVF, trials link it with higher clinical pregnancy rates and better embryo numbers. However, no meta-analysis has yet shown a clear effect on live birth, which is the outcome that matters most.
CoQ10, or coenzyme Q10, helps mitochondria make energy and also acts as an antioxidant, which is why it’s studied for eggs. According to PubMed, a 2020 meta-analysis of five randomised trials (449 women having IVF) found clinical pregnancy rates of 28.8% with CoQ10 and 14.1% without it. Live birth, though, showed no significant difference.
Similarly, a 2024 meta-analysis of six trials in women with diminished ovarian reserve (1,529 participants) linked CoQ10 with higher clinical pregnancy rates. The authors noted the trials’ methods were poorly reported. One of those trials, in women under 35 with low reserve, found more eggs retrieved and more good-quality embryos. Its pregnancy and live birth rates were higher but not significantly so.
Zooming out, the picture stays cautious. A 2024 Australian umbrella review from NICM concluded the evidence is insufficient to recommend nutrient supplements for female infertility, while finding no sign of significant harm. Likewise, a Cochrane review of antioxidants for female subfertility rated its evidence low to very low quality. In March 2026, Cochrane’s editors noted that seven of its included studies had since been retracted and two more had expressions of concern, although they judged the conclusions unchanged.
So is CoQ10 worth discussing? For some people, yes, as part of a broader plan and with someone who knows your history. It isn’t a shortcut, and the path to progress is never linear.
General information only, not individual medical advice. Always discuss supplements and herbal medicines with your treating practitioner.
Ubiquinone or Ubiquinol: Does the Form Matter?
Less than the marketing suggests. CoQ10 comes in two forms, ubiquinone and ubiquinol, and ubiquinol is often sold as better absorbed. In a randomised crossover study, ubiquinol wasn’t significantly better absorbed than ubiquinone. Both forms ended up in the blood mostly as ubiquinol anyway.
According to PubMed, that 2020 study gave 21 healthy adults aged 65 to 74 single doses of different formulations. Ubiquinol raised blood CoQ10 about 1.7-fold relative to standard ubiquinone, but the difference wasn’t statistically significant. Notably, the body converted most absorbed CoQ10 to ubiquinol whichever form went in.
That study was in older adults rather than women planning a pregnancy, so it may not translate directly. Even so, it’s a useful check on the idea that the more expensive form is automatically the better one.
How Long Does It Take to Improve Egg Quality?
Think in months, not weeks. The follicle that releases an egg starts its final growth phase around 85 days before ovulation, so changes made today mostly affect eggs released about three months from now.
In practice, that’s why I think of preparation as a three-month project rather than a quick fix. Positive change means sacrifice, and the payoff isn’t immediate. Furthermore, if you’re already in IVF, it’s worth discussing timing with your fertility specialist before changing anything.
When Should You Get Help With Egg Quality?
If you’re under 35 and have been trying for 12 months, or 35 and over and trying for six, see your GP. Go sooner if your periods are irregular or absent, or if you already know about a condition that affects fertility. Your GP can arrange the right tests and, where needed, a referral.
We don’t diagnose or treat infertility; that stays with your doctor. Our part is the nutritional, herbal and lifestyle work that sits alongside their care. That holds whether you’re just starting to plan or already working with a fertility specialist.
If you’d like help building a plan around egg quality, you’re welcome to get in touch with the clinic at our Geelong or Drysdale rooms. You can also read more about our fertility and pregnancy support, and, if PMOS is part of your picture, our PMOS page.
Frequently Asked Questions
Can you improve egg quality after 35?
You can’t reverse the effect of age on chromosomes, which is the biggest single factor. You can, however, address the modifiable ones: smoking, weight, diet and oxidative stress. Their effect on egg quality is plausible rather than proven, so it’s worth working with your GP or fertility specialist on timing.
What AMH level is considered low?
Laboratories use different units and reference ranges, so a number only means something alongside your age and history. In the main study of natural conception, “low” meant below 0.7 ng/mL, and those women still conceived at similar rates. Ask the doctor who ordered the test to interpret your result.
Does the pill affect AMH?
Yes. A 2024 systematic review found current pill use was associated with AMH readings roughly 17% to 31% lower. If you’re on the pill when AMH is measured, your result may underestimate your usual level, so mention it to whoever interprets the test.
What’s the difference between egg quality and egg quantity?
Egg quantity is how many eggs your ovaries are still developing, which AMH reflects. Egg quality is how likely each egg is to become a healthy embryo, which depends mostly on age and chromosomes. A low quantity doesn’t automatically mean poor quality, and the reverse is also true.
Should my partner take CoQ10 too?
Sperm health matters as much as egg health, and antioxidants have been studied in men too. That evidence is covered in the next part of this series, on sperm health. As with any supplement, it’s best discussed with your treating practitioner rather than started on spec.
References
Egg quality, age and AMH research
- Franasiak JM, Forman EJ, Hong KH, et al. The nature of aneuploidy with increasing age of the female partner: a review of 15,169 consecutive trophectoderm biopsies evaluated with comprehensive chromosomal screening. Fertil Steril. 2014;101(3):656-663.e1. https://doi.org/10.1016/j.fertnstert.2013.11.004
- Steiner AZ, Pritchard D, Stanczyk FZ, et al. 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
- Broer SL, van Disseldorp J, Broeze KA, et al. Added value of ovarian reserve testing on patient characteristics in the prediction of ovarian response and ongoing pregnancy: an individual patient data approach. Hum Reprod Update. 2013;19(1):26-36. https://doi.org/10.1093/humupd/dms041
- Werner L, van der Schouw YT, de Kat AC. A systematic review of the association between modifiable lifestyle factors and circulating anti-Müllerian hormone. Hum Reprod Update. 2024;30(3):262-308. https://doi.org/10.1093/humupd/dmae004
- Gougeon A. Dynamics of follicular growth in the human: a model from preliminary results. Hum Reprod. 1986;1(2):81-7. https://doi.org/10.1093/oxfordjournals.humrep.a136365
CoQ10 and antioxidant trials
- Florou P, Anagnostis P, Theocharis P, et al. Does coenzyme Q10 supplementation improve fertility outcomes in women undergoing assisted reproductive technology procedures? A systematic review and meta-analysis of randomized-controlled trials. J Assist Reprod Genet. 2020;37(10):2377-2387. https://doi.org/10.1007/s10815-020-01906-3
- Lin G, Li X, Jin Yie SL, Xu L. Clinical evidence of coenzyme Q10 pretreatment for women with diminished ovarian reserve undergoing IVF/ICSI: a systematic review and meta-analysis. Ann Med. 2024;56(1):2389469. https://doi.org/10.1080/07853890.2024.2389469
- Xu Y, Nisenblat V, Lu C, et al. Pretreatment with coenzyme Q10 improves ovarian response and embryo quality in low-prognosis young women with decreased ovarian reserve: a randomized controlled trial. Reprod Biol Endocrinol. 2018;16(1):29. https://doi.org/10.1186/s12958-018-0343-0
- Shang Y, Song N, He R, Wu M. Antioxidants and fertility in women with ovarian aging: a systematic review and meta-analysis. Adv Nutr. 2024;15(8):100273. https://doi.org/10.1016/j.advnut.2024.100273
- Showell MG, Mackenzie-Proctor R, Jordan V, Hart RJ. Antioxidants for female subfertility. Cochrane Database Syst Rev. 2020;8:CD007807 (editorial note updated 5 March 2026). https://doi.org/10.1002/14651858.CD007807.pub4
- Pandey C, Maunder A, Liu J, et al. The role of nutrient supplements in female infertility: an umbrella review and hierarchical evidence synthesis. Nutrients. 2024;17(1):57. https://doi.org/10.3390/nu17010057
Guidelines and supporting studies
- Pravst I, Rodríguez Aguilera JC, Cortes Rodriguez AB, et al. Comparative bioavailability of different coenzyme Q10 formulations in healthy elderly individuals. Nutrients. 2020;12(3):784. https://doi.org/10.3390/nu12030784
- Teede HJ, Tay CT, Laven JSE, et al. Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Hum Reprod. 2023;38(9):1655-1679. https://doi.org/10.1093/humrep/dead156
- Your Fertility. Age and fertility. https://www.yourfertility.org.au/everyone/age
This article is general information and not a substitute for individual medical advice. If you have been trying to conceive for some time, or have a health condition, please speak with your GP. For private health consultation claiming, please enquire with your health fund to assess coverage. Nutrition consultations are covered by some private health funds — please check with yours first.
