When You've Been Told Everything Looks Fine, but You're Still Not Pregnant
If you've been given a diagnosis of unexplained delayed time to conception, I want you to know something: you are not imagining it. Something is going on. It's just that the standard testing didn't find it.
That distinction matters, and it's exactly why I do what I do.
In my years of clinical practice, I have never met a couple with so-called unexplained fertility challenges where we couldn't find something worth addressing. The answer is almost always there. It just requires someone willing to look past the standard checklist.
What Does "Unexplained" Actually Mean?
Unexplained delayed time to conception is defined as not having conceived after 12 months of trying, where routine investigations haven't identified a clear cause — no ovulation issues, no significant sperm concerns, no blocked fallopian tubes, no obvious hormonal abnormalities. Around 15% of couples needing fertility support receive this diagnosis.
Here's the thing though. The medical journal Best Practice & Research Clinical Obstetrics & Gynaecology puts it well:
"Maybe all that unexplained infertility is not unexplained if better understood and assessed."
Exactly. The label doesn't mean there's no explanation. It means the standard investigations didn't find one. And standard investigations, as thorough as they are, don't look everywhere.
What Standard Testing Often Misses
Routine fertility workups are an important starting point — but they're designed to identify the most obvious causes. They're not built to look at the finer detail of your nutrient status, immune function, blood sugar regulation, or the health of the environment your eggs and sperm are maturing in.
Here's what I look at that most commonly gets missed.
The Vaginal Microbiome
This is one I get genuinely excited about, because it's so often overlooked and so treatable.
The vaginal microbiome is the community of bacteria in the vaginal environment — and its balance has a direct impact on fertility. An imbalanced vaginal microbiome can affect sperm survival, embryo implantation, and the risk of early pregnancy loss — even with no symptoms whatsoever. No discharge, no odour, nothing. You'd have no idea.
A healthy vaginal microbiome is predominantly Lactobacillus species, which maintain the ideal pH for sperm survival and support implantation. When other bacterial species dominate — a state called dysbiosis — that environment becomes less hospitable. Research by Moreno & Simon (2019) in Human Reproduction Update found that a non-Lactobacillus dominant microbiome is associated with significantly lower implantation and pregnancy rates, including in IVF cycles.
The good news is we can test this with a simple at-home swab, and it's very much something we can support.
Nutrient Status — "Normal" Isn't Always Enough
I don't just want your nutrient levels to be in the normal range. For fertility, we're aiming for optimal — which is often well above what a standard lab flags as adequate.
Vitamin D is a classic example. Many labs consider anything above 50 nmol/L as normal, but research suggests levels above 75 nmol/L are more supportive for fertility and a healthy pregnancy. I see low-normal vitamin D constantly — and it's one of the easiest things to address. B12 and iron tell the same story.
Methylation
Methylation is a set of biochemical processes that rely on B-vitamins — particularly B12 and folate — to support hormone balance, liver detoxification, and healthy cell division in a developing embryo. When methylation is impaired, the reproductive consequences can be significant.
Many people have gene variants (the most well-known being MTHFR) that affect how efficiently they process these nutrients. A methylation panel — covering B12, folate, homocysteine, and MTHFR variants — is always part of my fertility investigation.
Blood Sugar and Metabolic Health
Even subtle insulin resistance, not yet flagged on standard testing, can compromise egg quality, disrupt ovulation, and affect the uterine environment. This isn't only relevant for people with diabetes or a PCOS diagnosis — it's something I find across the board.
Fasting blood sugar alone doesn't tell the full story. Fasting insulin gives a much clearer picture, and it's something I include in almost every fertility work-up.
Thyroid Function
Even subclinical thyroid dysfunction — including thyroid autoimmunity — can significantly affect fertility, implantation, and early pregnancy outcomes. Hashimoto's in particular is often missed because a standard thyroid panel doesn't always include antibodies. A full thyroid panel is non-negotiable in my fertility work-ups.
Autoimmunity More Broadly
Thyroid autoimmunity isn't the only immune-related factor worth investigating. Other markers sometimes associated with delayed conception include coeliac disease, anti-cardiolipin antibodies, anti-sperm antibodies, and anti-nuclear (ANA) antibodies — none of which appear in routine fertility testing.
Egg and Sperm Quality — the Role of Oxidative Stress
The health of eggs and sperm is closely tied to antioxidant activity. When the body's protective capacity is overwhelmed — by smoking, endocrine-disrupting chemicals, blood sugar imbalances, a highly processed diet, or chronic stress — egg and sperm quality can suffer.
This is an area where diet, lifestyle, and targeted supplement and herbal support can make a genuine, measurable difference. A high-quality prenatal is always foundational. Beyond that, strong antioxidant support and a high-quality fish oil supplement are things I commonly include — though the right approach is always tailored to the individual.
The right supplement approach is really specific to you — what works for someone else may not be right for your situation. This is something I work through carefully with every client.
Hormone Health — Timing Is Everything
A full hormone assessment can highlight subtle imbalances with real downstream effects on egg quality, sperm health, and uterine receptivity. What I often find is that hormones were tested — but not at the right time. Hormones need to be measured on day 2 of your period and again 7 days post-ovulation to give meaningful information. A single random blood test can easily miss real imbalances.
Stress — It's Physiology, Not a Mindset Issue
I'm not going to tell you to just relax. But I do want to acknowledge that chronic stress — emotional or physical — elevates cortisol in ways that genuinely disrupt the hormonal signals required for ovulation, implantation, and early pregnancy. This is worth investigating and supporting properly, not dismissing.
You're Not at a Dead End
A diagnosis of unexplained delayed conception can feel like hitting a wall. But in my experience, it almost never actually is. There is usually more to find, more to support, and more to work with. You just need someone willing to keep looking.
If you'd love support getting to the bottom of what's going on, I'd love to chat. Book a free discovery call 🤍
References
Mol BW et al. Unexplained infertility: Is it over-diagnosed and over-treated? Best Pract Res Clin Obstet Gynaecol. 2018.
Moreno I, Simon C. Relevance of assessing the uterine microbiome in infertility. Hum Reprod Update. 2019.
Noventa M et al. May Underdiagnosed Nutrition Imbalances Be Responsible for a Portion of So-Called Unexplained Infertility? Reprod Sci. 2016.
Várbíró S et al. Effects of Vitamin D on Fertility, Pregnancy and Polycystic Ovary Syndrome. Nutrients. 2022.
Deroux A et al. Female Infertility and Serum Auto-antibodies: a Systematic Review. Clin Rev Allergy Immunol. 2017.
A S V et al. Role of Antisperm Antibodies in Infertility, Pregnancy, and Potential for Contraceptive and Antifertility Vaccine Designs. Vaccines. 2019.