Hyperemesis Gravidarum: A Guide to Understanding, Treating, and Finding Real Support

A Resource Guide for Patients, Families & Clinicians

What Hyperemesis Gravidarum Really Is, and Why It Deserves Serious, Compassionate Care

Hyperemesis Gravidarum (HG) is not “bad morning sickness.” It is not something to push through, or something that resolves with ginger tea and willpower. HG is a medical emergency hiding in plain sight, affecting an estimated 10%–15% of pregnancies, far more common than the public conversation suggests.

As Kristin Mallon, CNM and co-founder of Materna, says:

“Hyperemesis is a debilitating, physiological condition, not a psychological weakness, not morning sickness, and absolutely not something women should suffer through.”

At Materna, we see firsthand how misunderstood and undertreated HG remains. Women are often told to “wait it out,” “lose weight first,” or return to care only after dehydration becomes severe. The consequences which can be physical, emotional, and fetal, can be profound. But with early, evidence-based, multi-modality treatment, the outcomes can be transformed.

This guide explains what HG is, why it happens, what the research shows, and where families and clinicians can find reliable, evidence-supported resources. It also outlines Materna’s approach, which has reduced ER visits by 95% and helped 80% of patients feel dramatically better within two weeks.

Defining HG: The Windsor Criteria

HG is best defined using the Windsor definition, which offers clarity beyond outdated weight-loss–based criteria:

HG is diagnosed when a patient has all of the following:

1. Severe, debilitating nausea and/or vomiting beginning before 16 weeks.
2. Inability to eat or drink normally (functional malnutrition/dehydration).
3. Substantial impact on daily functioning, work, or basic self-care.
4. No alternative diagnosis explaining symptoms.

This framework matters because many patients meet these criteria far earlier than traditional definitions allow — and earlier disease recognition changes outcomes.

How Common Is HG? Much More Than We Think

Up to 90% of pregnant women experience some nausea and vomiting. But HG is different — more intense, more disabling, and more likely to bring women to the hospital.

HG alternates with spotting/bleeding as the #1 cause of early pregnancy hospital admissions.

Although official prevalence ranges around 0.3%–3%, newer research and clinical observation suggest 10%–15% is far more accurate. The gap comes from underdiagnosis, dismissal of symptoms, and outdated definitions that require weight loss before treatment.

Why HG Happens : The New Science of GDF-15 and IGFBP-7

The old theory was that HG was caused by high levels of hCG — has largely been disproven.

The new understanding, published in Nature and other leading journals, points to two fetal-placental hormones:

• GDF-15
• IGFBP-7

Women who develop HG appear to have either:

• Genetic sensitivity to GDF-15,
• Higher placental production of these hormones, or
• A combination of both.

This explains why:

• HG runs in families.
• HG intensity tends to be similar or worse in subsequent pregnancies.
• Women with baseline elevated GDF-15 (e.g., certain chronic conditions) may have more severe presentations.

It also opens the door to future therapeutics, such as preconception desensitization using medications like metformin or berberine — a direction early research is now exploring.

The Risks of Untreated HG : For Both Mother and Baby

When HG is undertreated, the medical consequences can be significant.

Maternal risks include:

• Electrolyte imbalance
• Wernicke’s encephalopathy (from B1 deficiency)
• Nutritional deficiencies
• Gallbladder disease
• GI disorders
• Long-term cardiovascular impacts
• 8x higher risk of PTSD

The mental health toll of HG is real and often overlooked. We cover it in depth in our guide to the connection between hyperemesis gravidarum and mental health.

Fetal and neonatal risks include:

• Preterm birth
• Low birth weight
• NICU admission
• Small-for-gestational-age infants
• Neural tube defects (from vitamin depletion)
• Possible increase in neurodevelopmental disorders

These risks are preventable when HG is diagnosed early and treated effectively. For more on the longer term picture, see the downstream effects of hyperemesis gravidarum on mothers and children.

Objective Tools That Change Everything: HELP and PUQE Scores

One of the most powerful shifts in HG care has been the use of objective scoring tools.

1. HELP Score (HER Foundation)

Categorizes severity and guides treatment.
Link: https://www.hyperemesis.org/tools/help-her-score/

2. PUQE Score (12-hr & 24-hr)

Validated scale for nausea/vomiting severity.
Link: https://www.pregnancysicknesssupport.org.uk/healthcare-professionals/puqe-score/

As Mallon explains:

“Once we quantify HG, clinicians can finally follow evidence instead of intuition. It takes the guesswork out and brings HG into the medical mainstream.”

We strongly encourage every clinician and every pregnant person who suspects HG to track symptoms using these tools.

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Hyperemesis Gravidarum Treatment Algorithms and Guidelines

• HER Foundation – Treatment Overview & Algorithm
  https://www.hyperemesis.org/about-hyperemesis-gravidarum/treatment/
• RCOG – Green-top Guideline No. 69 (HG Management)
  https://www.rcog.org.uk/guidance/browse-all-guidance/green-top-guidelines/management-of-nausea-and-vomiting-of-pregnancy-and-hyperemesis-gravidarum-green-top-guideline-no-69/
• NICE – Nausea and Vomiting in Pregnancy / HG Recommendations
  https://www.nice.org.uk/guidance/cg62
• Materna HG Guidelines
  https://www.maternaguidleins.com

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Materna’s Treatment Approach: What Works and Why

Materna uses an early, aggressive, layered protocol, pulling the most effective elements from ACOG, RCOG, HER Foundation, CMAJ, and peer-reviewed research.

Materna’s HG protocol includes:

• Frequent visits (2–3×/week)
• IV hydration + vitamins, especially:
  • Thiamine (B1)
  • Folate
  • B-complex
• Combination antiemetic therapy, not monotherapy
• Acid suppression
• Nutrient support
• Mental health screening
• Objective scoring at every visit

Thiamine first is not a small detail. Giving dextrose before thiamine can trigger a serious complication, which is why we explain it fully in our post on thiamine deficiency in hyperemesis gravidarum and preventing Wernicke encephalopathy.

The result?

• 80% of Materna patients report feeling significantly better within 2 weeks.
• 95% reduction in ER visits.
• 90% reduction in overall pregnancy care costs.
• Patients are able to maintain work, avoid hospitalization, and gain weight rather than lose it.

Staying employed through HG is its own battle. If you are navigating this at your job, read our guide to navigating hyperemesis gravidarum at work and your rights and protections.

This is what standard care should look like.

Preconception Care for Women With HG Histories

For women planning another pregnancy, preconception care offers meaningful advantages.

Recommendations:

• Full health assessment
• H. pylori testing (and treatment if positive)
• Review and correction of underlying GI, nutrient or endocrine issues
• Discussion of prophylactic medications
• Nutrient and lifestyle optimization
• Development of a pregnancy action plan
• Discussion about metformin or berberine before pregnancy

Nutrition is a cornerstone of getting ahead of HG. Our hyperemesis gravidarum dietary guide covers what to eat and drink when very little stays down.

Link: https://www.hyperemesis.org/1st-steps/prevention/

Early planning helps reduce severity and gives families a sense of control heading into conception.

Resource Library : Trusted Tools, Scores and Guidelines

Core Clinical Guidelines

• CMAJ HG Clinical Practice Updates: https://www.cmaj.ca
• RCOG Green-top Guideline: https://www.rcog.org.uk
• ACOG Practice Bulletin (NVP/HG): https://www.acog.org/clinical/clinical-guidance/practice-bulletin‍
• Pregnancy Sickness Support (UK): https://www.pregnancysicknesssupport.org.uk

Tools & Scores

• HELP Score: https://www.hyperemesis.org/tools/help-her-score/
• PUQE score: https://www.pregnancysicknesssupport.org.uk/healthcare-professionals/puqe-score/

Evidence-Based Patient-Friendly Resources

• HER Foundation: https://www.hyperemesis.org
• Pregnancy Sickness Support: https://pregnancysicknesssupport.org.uk/
• Materna’s HG Education Hub
• Materna's webinar recording: https://youtu.be/9B7iOy5B9tc

Checklists

Checklist: What to Do If You Suspect Hyperemesis Gravidarum

• Track symptoms with PUQE or HELP score.
• Begin hydration immediately (electrolytes > water).
• Take B1 (thiamine) — do not wait.
• Contact an HG-literate clinician (Materna offers virtual visits).
• Request early medication layering, not single-medication trials.
• Avoid herbal remedies as primary treatment (ginger is not therapeutic).
• Ensure someone supports your daily needs (food, childcare, transport).
• Monitor mental health closely.

Checklist for Clinicians: Evidence-Based HG Care

• Use an objective score at every visit.
• Administer IV fluids + thiamine before dextrose or other medications.
• Layer medications early (doxylamine/pyridoxine  + reglan + acid reducer).
• Check electrolytes regularly.
• Follow up every 24–72 hours until stable.
• Document functional impairment , not just weight.
• Avoid dismissive language (“it’s normal,” “it’s part of pregnancy”).
• Offer mental health support or screening.

Frequently Asked Questions About Hyperemesis Gravidarum

Is hyperemesis gravidarum a disability?

HG can qualify for workplace protections. While it is not automatically labeled a disability, its functional impact often meets the threshold for accommodations under disability and pregnancy protection laws. What matters is documented functional impairment, not a single label. Our guide to navigating HG at work explains how to request accommodations.

Does hyperemesis gravidarum affect the baby?

When HG is treated early and well, most babies are born healthy. The risks to the baby, such as low birth weight or preterm birth, rise mainly when HG goes undertreated and the mother becomes dehydrated and nutritionally depleted. Early, aggressive care is what protects both mother and baby.

How is HG different from morning sickness?

Morning sickness is uncomfortable but does not stop you from eating, drinking, or functioning. HG does. With HG the nausea and vomiting are severe enough to cause dehydration, weight loss, and an inability to manage daily life. It is a medical condition, not a normal phase to push through.

Is there an HG clinic near me in NYC?

Yes. Materna is the Hyperemesis Treatment Center of NYC, based in the West Village, offering same week appointments for HG evaluation, IV hydration, and evidence-based treatment. We also offer virtual consults for patients outside NYC.

How Materna Can Help in NYC and Virtually

Materna is the Hyperemesis Treatment Center of NYC, offering:

• Early pregnancy evaluation
• HG scoring and diagnosis
• IV hydration and vitamin therapy
• Evidence-based medication protocols
• Functional nutrition support
• Mental health screening
• Frequent follow-up
• Preconception counseling
• Virtual visits for patients anywhere in the U.S.

If you're in the NYC area:

👉 Book an initial HG consult at Materna:
Book Now

If you're outside NYC:

👉 Book a virtual telehealth HG consult

“No one should face HG alone. With the right care, women can reclaim their pregnancies and their daily lives.”
— Kristin Mallon, CNM

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