Behind the Scenes: How I Read Fertility Test Results

sarah9691
Sep 3
4 min read

Fertility testing can feel overwhelming. A page of numbers, ranges, and jargon. I often hear clients say, “Everything looks normal, but we still can’t conceive,” or “I don’t know what these results even mean.”

In my work, I see this all the time. Lab results are powerful tools, but they’re just one piece of the fertility puzzle. Today, I want to give you a peek behind the scenes at how I interpret these results, and why context matters as much as numbers.

Looking Beyond ‘Normal’ Ranges

Most lab ranges are designed to detect disease, not to optimise fertility. A result that’s technically “within range” might still be low or high enough to affect egg or sperm quality.

For example:

Ferritin – a measure of your iron stores. Many labs consider anything above 15–20 µg/L normal. But for fertility and energy, levels closer to 50–100 µg/L are often more supportive. High ferritin may also indicate inflammation in the body, which can affect fertility in other ways.
Vitamin D – a level above 50 nmol/L might be considered normal, yet for fertility, levels closer to 100-150 nmol/L tend to support optimal functioning and implantation.
Vitamin B12 – labs usually measure total B12, but the more relevant marker is active B12 (holotranscobalamin), which shows how much B12 is actually able to be absorbed into your cells. Combining this with full blood count (FBC) markers can give a clearer picture of whether the B12 is actually getting into the cells to support egg and sperm health, DNA synthesis, and hormone production.

These examples show why it’s essential to understand the difference between “normal” and “optimal for fertility.”

Considering the Whole Person

Numbers don’t exist in isolation. When I review results, I always consider the bigger picture: nutrition, sleep, stress, physical activity, gut health, and even environmental exposures.

A common example is subclinical hypothyroidism. Your GP might class TSH levels up to 4–5 mIU/L as “normal,” but for fertility, research suggests optimal TSH is closer to 1.5–2 mIU/L. Even if your results fall within the standard range, slightly elevated TSH can affect egg quality, ovulation, and implantation. When combined with other factors—like low iron, poor sleep, or high stress—these “normal” results may still be limiting fertility outcomes.

Understanding lifestyle and health context alongside lab results helps explain why numbers may appear adequate on paper but aren’t fully supporting fertility in practice.

Patterns Over Single Results

I rarely make recommendations based on one marker alone. Trends and combinations often tell a clearer story than isolated results.

For instance:

Low ferritin combined with mildly elevated TSH might suggest thyroid-related nutrient issues.
Suboptimal reproductive hormones, such as slightly elevated FSH or low LH, combined with disruptions to circadian rhythm, like poor sleep, high stress, or frequent travel, can impact fertility even if each factor looks only mildly off on its own. Seeing these patterns can actually be reassuring, as it suggests that the hormone changes may not be fixed and may improve with targeted lifestyle adjustments.
Low active B12 despite a normal total B12, with subtle FBC changes, might indicate poor absorption or functional deficiency.

Looking at patterns helps me see where intervention may have the most impact and avoids overcorrecting one lab value without addressing the underlying cause.

Connecting Tests to Actionable Steps

Once I understand the context, I create a personalised approach – not just recommending supplements, but building lifestyle and dietary support that addresses root causes.

Tests guide the “what” and “where to start”, but the “how” comes from foundational work:

Improving diet and nutrient intake
Supporting sleep and stress management
Optimising gut and microbiome health
Encouraging moderate, consistent movement

This approach doesn’t just improve lab markers; it improves overall fertility outcomes.

Follow-Up and Reassessment

Tests are snapshots in time. Foundational changes, like improving sleep or supporting gut health, often shift results over weeks or months. This creates a feedback loop: improving lifestyle habits can positively influence blood markers, hormone balance, and microbiome results, which in turn supports fertility.

By seeing testing and foundational work as interconnected, we get a clearer, more actionable picture than relying on lab results alone.

Key Takeaways

Fertility tests are powerful tools, but they’re most useful when interpreted in context.
Numbers alone don’t tell the full story; lifestyle, health, and environment all play a role.
Patterns, not single results, are often the most revealing.
Tests guide your next steps, but the foundational work, nutrition, sleep, stress, movement, gut health, needs to be done to support fertility and improve outcomes.

💡 Want a simple reference?

I’ve created a fertility testing summary download, which highlights common tests, where to access them, and when it might be worth investigating further. You can grab it here: Testing summary.

By taking a holistic, context-driven approach to fertility testing, you can move beyond confusion or frustration and focus on the steps that truly make a difference. Lab results are guides, not the whole story, and pairing them with foundational health work gives you the best chance of a positive outcome.

Sarah