The HPA & HPG Axes — What Chronic Stress Is Really Doing to Your Fertility

If you have ever been told to "just relax" when trying to conceive, you have probably felt the frustration of that advice. But here is the thing — there is actually profound biological truth buried inside that oversimplified suggestion. Stress really does affect your fertility. Not because you are doing something wrong, but because of a deeply intelligent survival mechanism built into every human body.

To understand why, we need to talk about two of the most important hormonal axes in your body — the HPA axis and the HPG axis — and what happens when they come into conflict.

What Is the HPA Axis?

The HPA axis stands for the Hypothalamic-Pituitary-Adrenal axis. It is your body's primary stress response system — the biological pathway that governs how you respond to perceived threat.

When your brain detects stress — whether that is a deadline, a difficult relationship, financial pressure, emotional trauma, or even the chronic low-grade anxiety of modern life — your hypothalamus sends a signal to your pituitary gland, which in turn signals your adrenal glands to release cortisol and adrenaline.

This is your fight-or-flight response. It is ancient, powerful, and designed to keep you alive.

In short bursts, this system is incredibly useful. It sharpens your focus, mobilises energy, and prepares your body for action. But when stress is chronic — when your body stays in a state of low-grade activation day after day — the consequences begin to ripple through every system in your body. Including your reproductive system.

What Is the HPG Axis?

The HPG axis stands for the Hypothalamic-Pituitary-Gonadal axis. This is your reproductive hormonal pathway — the system that governs ovulation, menstrual cycle regulation, and fertility.

Your hypothalamus releases GnRH (gonadotropin-releasing hormone), which signals the pituitary to release LH and FSH — the hormones that trigger ovulation and support a healthy cycle. This cascade is exquisitely sensitive, finely tuned, and deeply responsive to your overall state of health and safety.

Here is the critical thing to understand: the HPA axis and the HPG axis share the same starting point — the hypothalamus. And when the hypothalamus is busy managing a stress response, reproductive function takes a back seat.

The Pregnenolone Steal

There is a fascinating biochemical mechanism that illustrates this conflict perfectly. Cortisol — your primary stress hormone — is made from pregnenolone, the same precursor molecule used to make your reproductive hormones including progesterone, oestrogen and testosterone.

When your body is under chronic stress and needs to keep producing cortisol, it will divert pregnenolone away from reproductive hormone production to meet that demand. This is sometimes called the pregnenolone steal or cortisol steal.

The result? Lower progesterone. Disrupted oestrogen. Irregular cycles. Reduced ovarian function. Difficulty conceiving.

Your body is not broken. It is making a logical choice based on the information it is receiving: this is not a safe time to create life.

Your Body Prioritises Survival Over Reproduction

This is perhaps the most important thing to understand about stress and fertility: from an evolutionary perspective, reproduction is a luxury. Survival is the priority.

If your nervous system is receiving signals of chronic threat — even subtle, modern-day signals like overwork, relationship conflict, financial worry, or unprocessed trauma — your body will suppress reproductive function. Not because it is failing you, but because it is protecting you.

It is asking: is this a safe enough environment to bring new life into?

When the answer the body receives, day after day, is not yet — fertility suffers.

The Stress of Trying to Conceive

Here is where it gets particularly complex for women on a fertility journey. The stress of trying to conceive — the monthly hope and disappointment, the medical appointments, the pressure, the grief — can itself become a significant source of HPA activation.

This creates a painful cycle: stress suppresses fertility, and the experience of fertility challenges creates more stress. Understanding this cycle is not about blaming yourself. It is about finding compassion for your nervous system and recognising that healing the stress response is not a nice-to-have — it is a fundamental part of supporting your fertility.

What Can You Do?

Supporting your HPA-HPG axis balance is not about eliminating stress entirely — that is neither possible nor necessary. It is about shifting your nervous system out of chronic activation and into a state of greater safety and regulation.

Some of the most powerful ways to do this include:

Somatic practices — breathwork, yoga, gentle movement that signals safety to your nervous system

Subconscious healing — hypnotherapy and inner child work to address the root causes of chronic stress activation

Nervous system regulation — practices like yoga nidra, meditation and somatic shaking to discharge stored stress

Nourishment — supporting your adrenals with adequate sleep, blood sugar balance and key nutrients including magnesium, vitamin C and B vitamins

Emotional processing — creating space to feel and release the grief, fear and disappointment of the fertility journey rather than pushing through it

Addressing trauma — unresolved trauma keeps the nervous system in a state of chronic activation. Working with a trauma-informed practitioner can be profoundly supportive

A Note on the Bigger Picture

The HPA and HPG axes are just two pieces of a much larger picture. Your fertility is not only physical — it is emotional, mental, energetic and spiritual. When we tend to all five layers of our being, we create the conditions for the body to feel truly safe enough to conceive.

This is the foundation of my work and the heart of my book, Fertility Isn't Linear. If this resonates with you and you would like to go deeper, I invite you to explore the Five Bodies framework — a holistic map of fertility that addresses every layer of your whole self.

You are not broken. Your body is responding intelligently to the life it is living. The invitation is to help it feel safe enough to create.

Want to go deeper? Download my free guide 5 Holistic Practices That Supported My Natural Pregnancy at 41 — or explore Fertility Isn't Linear, now available in paperback and ebook on Amazon.