Hyperemesis Gravidarum: Why It Happens — And Where Nervous System Support Fits In

For many women, nausea in pregnancy is expected. But for some, it becomes something far more intense — hyperemesis gravidarum (HG).

HG is not just “bad morning sickness.” It’s a complex, whole-body condition that can significantly impact a woman’s health, well-being, and ability to function during pregnancy.

Understanding why it happens is the first step toward better support — and this is where a nervous system-focused approach can play an important role.

What Is Hyperemesis Gravidarum?

Hyperemesis gravidarum is a severe form of pregnancy-related nausea and vomiting that can lead to:

- Persistent vomiting  

- Dehydration  

- Nutrient depletion  

- Weight loss  

- Increased sensitivity to smells, motion, and food  

It often requires medical support — and importantly, it is not caused by stress, mindset, or anything the mother has done wrong.

The Real Cause: It’s More Than Just Hormones

For many years, pregnancy nausea was attributed simply to hormones like hCG or estrogen. While these do play a role, newer research has uncovered a much more specific mechanism.

The Role of GDF15

A hormone called GDF15, produced by the placenta, appears to be a key driver of nausea in pregnancy.

This hormone communicates directly with the brainstem — the part of the brain responsible for nausea and vomiting.

What’s important is this:

> It’s not just how much of this hormone is present — it’s how sensitive the mother’s nervous system is to it.

Women who are more sensitive to this signal tend to experience more severe symptoms.

Genetics and Sensitivity

Hyperemesis gravidarum often runs in families, suggesting a strong genetic component.

This means some women are simply more neurologically sensitive to the signals of pregnancy — particularly those coming from the placenta.

This is not a flaw — it’s a biological variation.

Where the Nervous System Comes In

This is where things become highly relevant to chiropractic care. HG is increasingly understood as involving a brain–body response, particularly within the autonomic nervous system.

The autonomic nervous system regulates:

- Digestion  

- Nausea reflexes  

- Sensory processing (smell, taste, motion)  

- Stress and adaptation  

When the nervous system is in a more heightened or dysregulated state, it may:

- Amplify nausea signals  

- Increase sensory sensitivity  

- Reduce the body’s ability to adapt to hormonal changes  

In other words:

> The same signal from the placenta may feel manageable to one nervous system — and overwhelming to another.

Supporting the Body Before and During Pregnancy

While there is no guaranteed way to prevent hyperemesis gravidarum, there are ways to support the body’s resilience and adaptability — particularly when implemented before or early in pregnancy.

🧠 Nervous System Regulation

Supporting the nervous system is a key piece of the puzzle.

Chiropractic care aims to:

- Improve communication between the brain and body  

- Support balance within the autonomic nervous system  

- Enhance the body’s ability to adapt to change  

This may help reduce the intensity of how nausea signals are experienced.

🥦 Nutritional Support (Preconception and Early Pregnancy)

Nutrient status plays an important role in how the body copes with the demands of pregnancy. Particular nutrients that have been associated with nausea regulation and nervous system support include:

- Vitamin B6 – commonly used in early pregnancy to help reduce nausea  

- Vitamin B1 (thiamine) – essential for energy production and particularly important in cases of prolonged vomiting  

- Magnesium – supports nervous system regulation and stress resilience  

- Zinc – plays a role in immune function, hormone signalling, and taste/smell perception  

Optimising these nutrients before conception and in early pregnancy may support the body’s ability to better tolerate the physiological changes of pregnancy.

🦠 Gut Health and Digestive Function

The gut and brain are closely connected, and digestive function plays a role in nausea.

Supporting gut health may include:

- Promoting healthy digestion prior to pregnancy  

- Addressing underlying reflux or digestive discomfort  

- Supporting balanced blood sugar levels  

- Encouraging a whole-food, nutrient-dense diet  

A well-functioning digestive system may help reduce the overall burden on the body during early pregnancy.

💧 Early and Proactive Care

For women with a history of severe nausea or HG, early support is essential. This may include:

• Thorough pre-conception care, making sure nutritional deficiencies are addressed, and nutrition stores are built up.

• Addressing any other underlying health issues.

• Proper hydration and electrolyte support

Early intervention often leads to better outcomes than waiting for symptoms to escalate.

A Whole-Person Approach Matters

Hyperemesis gravidarum is multifactorial. It involves the interaction between:

- Placental signalling  

- Genetic sensitivity  

- Nervous system regulation  

- Nutritional status  

- Digestive health  

No single approach addresses all aspects — which is why a collaborative, supportive strategy is so important.

Final Thoughts

Hyperemesis gravidarum is a complex condition rooted in the interaction between the placenta and the maternal nervous system.

While we cannot change the signals coming from pregnancy, we can support how the body processes and responds to those signals.

By supporting the nervous system, optimising nutrient status, and improving overall resilience before and during pregnancy, we can help the body navigate this period with greater adaptability.

At our practice, our focus is on helping the nervous system function at its best — especially during times of significant change like pregnancy.

If you or someone you know is navigating severe pregnancy nausea, know that support is available — and you don’t have to go through it alone.