Hyperemesis Gravidarum Information Hub
Severe pregnancy nausea is not "morning sickness with a bad attitude." It is a real medical condition.
Here you will find research-based information, treatments, and support for those going through it.
This portal brings together the latest research from 2025 and 2026, including the GDF15 protein breakthrough, new treatments, and active clinical trials worldwide.
What is HG?
Understanding the condition, causes, and symptoms
Treatments & Medications
Approved medications and innovative therapies
Clinical Trials
Active studies and new trials worldwide
New Research
Breakthroughs from 2025 and 2026
Nutrition & Hydration
What to eat, IV fluids, vitamins
Fetal Health
Effects on the baby and birth outcomes
Psychological Approach
Trauma, PTSD, depression, and emotional support
Future Pregnancies
Recurrence, prevention, and planning ahead
Lifestyle & Management
Complementary therapies, rest, and daily management
Stories & Support
Community, organizations, and support groups
Links & Resources
International organizations and further information
What is Hyperemesis Gravidarum?
Understanding the medical condition, its causes, and symptoms
How is HG different from regular nausea?
Nausea and vomiting of pregnancy (NVP) affects up to 80% of pregnancies and typically resolves without complications. Hyperemesis Gravidarum (HG) is the most severe form: persistent vomiting, weight loss exceeding 5% of pre-pregnancy body weight, dehydration, and electrolyte disturbances. HG is a medical condition that requires treatment.
Breakthrough: The GDF15 Protein
A landmark study in Nature (2023) identified that the protein GDF15, produced primarily by the placenta, binds to the GFRAL receptor in the brain's vomiting center. Women with lower baseline GDF15 levels before pregnancy are more sensitive to the sharp rise during pregnancy, explaining why some women suffer far more than others.
Risk Factors
Prior history of HG (strongest risk factor, RR 8.92), first pregnancy, female fetus, multiple gestation, family history, and genetic factors (mothers with a GDF15 mutation whose fetus carries the normal gene are at highest risk).
Symptoms
📅 Timeline
Onset: weeks 4 to 6 of pregnancy. Peak: weeks 8 to 12. In 90% of cases it resolves by week 20. In some cases it persists until delivery.
Core Symptoms
Persistent nausea (often 24/7), vomiting more than 3 times per day, weight loss exceeding 5%, inability to eat or drink, and excessive salivation (ptyalism).
Signs of Dehydration
Ketones in urine, orthostatic hypotension, rapid heart rate, dry mucous membranes, reduced urine output. Research from 2026: hyponatremia in 29%, hypokalemia in 21%, hypochloremia in 24% of hospitalized patients.
⚠️ Wernicke's Encephalopathy (Medical Emergency)
Thiamine (vitamin B1) deficiency can cause Wernicke's encephalopathy: confusion, abnormal eye movements, gait disturbances, and memory impairment. It typically appears between weeks 10 and 15 of pregnancy, after approximately 7 weeks of vomiting. This is a medical emergency. Without treatment it can cause irreversible brain damage.
Frequently Asked Questions
Treatments & Medications
Approved medications, innovative therapies, and clinical management
✅ First-Line Medications
Medications proven safe in pregnancy and recommended as initial treatment
| Medication | Brand Name | Mechanism | Dosing |
|---|---|---|---|
| Doxylamine + Pyridoxine | Diclegis / Bonjesta / Xonvea | H1 histamine blocker + vitamin B6. The only FDA-approved medication for pregnancy nausea | 2 tablets at bedtime. If needed: 1 in the morning. Maximum 4 per day |
| Metoclopramide | Reglan / Maxolon | Dopamine D2 receptor antagonist in the chemoreceptor trigger zone. Increases gastric motility | 5 to 10 mg orally or IV every 8 hours |
| Ondansetron | Zofran | Selective 5-HT3 serotonin receptor blocker. The most widely used medication in the US | 4 to 8 mg orally or IV every 8 hours |
📚 On Ondansetron (Zofran) Safety
Most studies have not found an increased risk of birth defects. A 2022 meta-analysis found no overall link to abnormal pregnancy outcomes. Some studies reported a small dose-dependent increase in risk of ventricular septal defect (VSD). RCOG guidelines: second line. Expert consensus: safe and effective.
⚠️ Second-Line Medications
Used when first-line treatment is insufficient
Promethazine (Phenergan)
First-generation antihistamine (H1 blocker) with anticholinergic properties. Dosing: 12.5 to 25 mg orally, intramuscularly, or rectally every 4 to 8 hours. Main side effect: significant drowsiness.
Corticosteroids
Reserved for refractory cases only. Methylprednisolone: 16 mg every 8 hours for 3 days, then tapered over two weeks. Avoid before week 10 (small risk of cleft palate). Prednisolone is considered safer as it is metabolized by the placenta.
Chlorpromazine (Thorazine)
Phenothiazine antipsychotic with antiemetic properties. Last resort only due to significant side effects including severe sedation.
Intravenous Fluid Therapy
Initial: 2 liters Lactated Ringer's over 2 to 3 hours. Maintenance: titrated to urine output (over 100 ml/hour). Daily electrolyte monitoring. Critical: thiamine (100 to 500 mg IV three times daily) must be given before or alongside any dextrose infusion to prevent Wernicke's encephalopathy.
Enteral Nutrition (Tube Feeding)
Feeding via nasogastric or nasojejunal tube. Appropriate for patients unable to eat orally. Shown to reduce symptoms and shorten hospital stays. Preferred over TPN due to fewer complications.
Parenteral Nutrition (TPN)
Last resort only. Direct intravenous nutrition. Carries significant risks: line infections, thrombosis, liver complications. Used only when all other options have failed.
🌟 The Future: Blocking the GDF15-GFRAL Pathway
Four therapeutic strategies are under investigation: anti-GFRAL antibody, antagonist peptide, small molecule inhibitor, and targeted nanoparticles.
NGM120 (The Leading Candidate)
A GFRAL antagonist monoclonal antibody, developed by NGM Biopharmaceuticals. Mechanism: blocks GDF15 from binding to the GFRAL receptor. Administration: single subcutaneous injection. Good tolerability in over 140 non-pregnant participants. Funding: $122 million (Series A, July 2024). Phase 2 (EMERALD) began February 2025.
Metformin as Prevention
Metformin (a common diabetes medication) raises GDF15 levels, potentially "pre-conditioning" the body in advance. Use for 6 or more months before pregnancy has been linked to over 70% reduction in HG risk. HG incidence of only 1.1% in women who took metformin. This may represent the first-ever HG prevention strategy.
🔍 Questions to Ask Your Doctor
• Can medication be combined with complementary therapies?
• Do I need thiamine supplementation?
• What is the plan if my current medication is not helping?
• Am I eligible for any of the clinical trials?
• Should I consider home IV therapy?
Clinical Trials
Active research and new trials worldwide
EMERALD: NGM120 vs. Hyperemesis Gravidarum
The world's first clinical trial of an anti-GFRAL antibody in pregnant women with HG. Administration: single subcutaneous injection. Participants: weeks 9 to 16 of pregnancy. Design: randomized, placebo-controlled. Follow-up: 7 days. Sites: UK and Australia.
ID: ISRCTN76681798 (UK) / ACTRN12624001421527 (AUS)
Reducing HG Risk with Metformin
A study on pre-pregnancy metformin use as a prevention strategy for HG.
ID: NCT07129473
Capsaicin + Metoclopramide + Ondansetron
Trial of topical capsaicin in combination with standard antiemetics. Location: Women & Infants Hospital, Rhode Island, USA.
ID: NCT05098067
Mirtazapine vs. Ondansetron
Randomized comparative trial: mirtazapine vs. ondansetron vs. placebo (1:1:1). Multicenter.
ID: NCT03785691
Hypnosis in Hyperemesis Gravidarum
Study on the efficacy of hypnosis as a complementary therapy in HG.
ID: NCT04828967
New Research
Breakthroughs and discoveries from 2025 and 2026
The Lancet: Comprehensive Review (2025)
A major review in The Lancet (volume 406) summarized a decade of research. Conclusion: hypersensitivity to rising GDF15 levels in pregnancy is the primary driver. Concerns about pregnancy drug labeling and the false assumption that HG resolves on its own lead to systematic under-treatment of women.
Mental Health & HG (2025)
A retrospective cohort study in Lancet Obstetrics found significant neuropsychiatric and mental health outcomes associated with HG. A further study in Lancet Psychiatry (Finnish national registry) confirmed the link between HG and depression.
Long-Term Outcomes in Children (2025)
A population-based sibling study found that in-utero HG exposure is associated with elevated risk of abnormal brain growth, developmental delay, autism, childhood cancer, and respiratory disorders.
Metformin for Prevention (2025/2026)
Multiple observational studies in AJOG demonstrated that pre-pregnancy metformin (6+ months) dramatically reduces HG risk. A potential paradigm shift in prevention.
Electrolyte Disorders (2026)
A study in Frontiers in Medicine quantified blood and electrolyte disturbances in HG: hyponatremia in 29%, hypokalemia in 21%, hypochloremia in 24% of hospitalized patients.
"Mild HG" is a Misnomer (2025)
A commentary in The Lancet argues that "mild hyperemesis" is a fundamentally flawed concept. It criticizes the systematic dismissal of HG symptoms and the tendency to classify cases as mild when they are not.
Nutrition & Hydration
What to eat, IV protocols, and critical vitamins
⚠️ Thiamine (Vitamin B1): The Most Critical Nutrient
Dosing: 100 to 500 mg IV three times daily. Must be given before any dextrose infusion (administering dextrose without thiamine can cause Wernicke's encephalopathy). Oral thiamine may be insufficient due to vomiting. A carbohydrate-heavy diet (common in HG because it is the only tolerated food) depletes thiamine more rapidly.
More Tolerable Foods
Crackers, dry toast, white rice, cold foods (less odor), protein snacks (nuts, cheese), bland low-fat foods, ice lollies and ice cubes, sour flavors (lemon, sour candy), small sips of electrolyte drinks.
IV Fluid Protocol
Initial: 2 liters Lactated Ringer's over 2 to 3 hours. Titrate to urine output (over 100 ml/hour). Daily monitoring of sodium, potassium, chloride, magnesium, and phosphate. Hypokalemia is particularly dangerous (cardiac risk).
Common Nutritional Deficiencies
Most women with HG consume less than half the recommended amounts of: thiamine, iron, calcium, magnesium, vitamin D, and iodine. Monitoring and supplementation are essential.
💡 Practical Tips
• Eat when you are hungry, not by the clock
• Small, frequent meals (every 1 to 2 hours)
• Favor carbohydrate- and protein-rich foods (they reduce nausea more than fatty foods)
• Avoid fatty, spicy, or strongly-scented foods
• Keep crackers by the bed for morning
• Cold food is better tolerated (less odor)
Fetal Health
Effects on the baby, birth outcomes, and long-term results
📚 Findings from Meta-Analyses
Preterm birth (before week 34): double the risk. Prematurity overall: four-fold risk. Low birth weight (under 1,500 g): elevated risk. Small for gestational age (SGA): elevated risk. NICU admission, resuscitation, and placental abruption: elevated risk.
Birth Outcomes
Prolonged maternal starvation and nutritional deficiencies interfere with the supply of nutrients and metabolic processes required for normal fetal development. Early treatment and adequate nutrition can significantly improve outcomes.
Long-Term Outcomes in Children
Children exposed to HG in utero were found to have a 3.82-fold elevated risk of allergies, chronic constipation, reflux, growth delays, lactose intolerance, chronic respiratory infections, and sleep problems.
Neurodevelopmental Effects
Higher rates of attention disorders, developmental delays, autism, anxiety, and sleep problems in offspring. Abnormal brain growth and childhood cancer (small but statistically significant association).
💚 Important Note
Many of these outcomes are likely related to the severity and duration of maternal malnutrition, not to HG itself. HG that is properly treated with adequate nutrition may lead to better fetal outcomes. Early and aggressive treatment is the key.
Psychological Approach
Trauma, depression, PTSD, isolation, identity loss, and support resources
💔 PTSD and Hyperemesis: One of the Only Pregnancy Conditions Documented to Cause Trauma
⚠️ Hyperemesis is one of the few pregnancy conditions documented as a cause of PTSD
18% of women who experienced HG meet the full diagnostic criteria for PTSD, and over 50% experience sub-threshold trauma symptoms. Symptoms include: avoidance (of places, smells, and foods that recall the HG experience), emotional numbing, hypervigilance, re-experiencing the sensations of nausea and vomiting, and sensitivity to triggers such as food smells, hospitals, or words associated with pregnancy. At 8 weeks postpartum, women who experienced HG showed significantly higher PTSD scores than women with mild or no nausea. HG-related PTSD is directly linked to breastfeeding difficulties, relationship problems, financial hardship, and reduced functioning. Symptoms can persist for years after the pregnancy.
Sources: HER Foundation; Mitchell-Jones et al., BJOG 2017 (systematic review); Archives of Women's Mental Health 2018; Lancet Obstetrics 2025 (476,857 women, 18 countries)
Depression: During and After Pregnancy
49% of women with HG experience depression during pregnancy (vs. 6% in the general population). 29% experience depression 6 weeks postpartum (vs. 7% in controls). A retrospective cohort study in The Lancet (2025) found a 2.7-fold elevated postpartum depression risk. A Finnish national registry study confirmed the association. Striking finding: HG with metabolic disturbance (more severe, aggressively treated) showed a decrease in depression risk, vs. "mild" HG. Implication: adequate treatment is protective. Symptoms can persist for years.
Sources: J Maternal-Fetal & Neonatal Medicine 2022; Lancet Obstetrics 2025; King's College London
Medical Invalidation Trauma
"It's just morning sickness." "Have you tried ginger?" "It's psychological." Women with HG repeatedly report being dismissed by medical staff, having symptoms minimized, and having their condition attributed to anxiety or imagination. Negative patient experience is documented as a direct risk factor for pregnancy termination and suicidal ideation (Nana et al., 2022). 82.8% of patients have limited daily activity, yet many face dismissal. Validation (recognition that this is a real and severe condition) is a documented protective factor that reduces risk of serious psychological outcomes.
Sources: Nana et al., Women's Health 2022; Frontiers in Health Services 2025; Psychiatric Times
Mother-Infant Bonding
HG itself does not directly impair mother-infant attachment. A slight reduction in bonding was observed in early pregnancy (weeks 7 to 16), but the effect diminished later in pregnancy (after week 26). By contrast, postpartum depression (2.7x more common after HG) does impair bonding. The indirect pathway: HG causes depression, and depression affects the relationship. A 2023 study found infants exposed to HG in utero showed reduced attention during play with their mothers. Women describe that during severe HG "there was no room for anything else, including the baby," but afterward they invested significant effort to reconnect.
Sources: PMC7554497 (prospective multicenter study); ScienceDirect 2023; PubMed 21413857
⚠️ Pregnancy Termination and Suicidal Ideation
5% of women terminated a wanted pregnancy due to HG. A further 52% considered it. 25.5% reported occasional suicidal thoughts, 6.6% reported persistent suicidal thoughts. Reasons for termination: inability to care for themselves or existing family (66.7%), fear that they or the baby would die (51.2%), fear the baby would have a disability (22%). Documented risk factors: difficulty accessing medication, negative patient experience, lack of validation from medical staff. Protective factors: holistic support from family, friends, and therapists.
📞 Crisis Resources: Samaritans: 116 123 (UK) | Crisis Text Line: text HOME to 741741 (US) | International Association for Suicide Prevention: find your country's crisis line. Routine mental health screening and suicide risk assessment is strongly recommended.
Sources: Nana et al., Women's Health 2022 (over 5,000 participants); PMC9574451
💜 The Wider Impact: Isolation, Identity, Family, and the Future
Social Isolation and Loneliness
HG enforces total social isolation. Women are confined to bed for months, unable to work, attend events, or even hold a conversation. The feeling that "life is going on without me" deepens depression. Worse still, dismissive medical attitudes contribute to self-stigma that drives further isolation. Research shows depression and anxiety are more common in women with HG who have weak family and social support networks.
Sources: ScienceDirect 2025 ("Deprived of my autonomy"); PMC5780564; Taylor & Francis 2023
Grief and Identity Loss
HG causes multiple losses that are rarely acknowledged: the "happy pregnancy" that was imagined, career momentum and even employment, the ability to parent existing children, financial independence, friendships and social connections. A 2025 qualitative study (Sweden) described women who "watched themselves disappear from the roles of their lives: mother, partner, professional." This identity loss complicates infant bonding and alters relationship dynamics. Some women choose to forgo further children, and grieve the family they had planned.
Sources: ScienceDirect 2025 (PubMed 40088682); Bloom Psychotherapy; Psychiatric Times
Impact on Partners and Family
HG does not happen in a vacuum. Partners report anger, loneliness, burnout, and secondary trauma. Over 80% of women report that HG had a negative psychosocial impact, including job loss, financial stress, and relationship problems. HG-related PTSD is specifically linked to relationship difficulties as a documented outcome. Existing children in the family are affected when a mother is bedridden for months. A Psychology Today article (December 2025) described partners as playing "a vital role in restoring a sense of reality, dignity, and care."
Sources: Psychology Today 2025; HER Foundation; PMC5056484; Taylor & Francis 2023
Fear of Future Pregnancy
40% of women with HG delay a subsequent pregnancy. 52% did not become pregnant again at all, and two-thirds cited HG as the reason. 23% considered or underwent pregnancy termination in subsequent pregnancies due to fear of recurrence. Importantly, this is not a rational decision but a traumatic avoidance response. Women describe panic attacks at the mere thought of future pregnancy. Recurrence rates range from 15% to 89% depending on study methodology. Relationship conflict over family planning is a common outcome.
Sources: PMC8457209 (MOTHER study follow-up); HER Foundation; StatPearls
Return to Work and Professional Impact
82.8% of HG patients have limited daily functioning. Work absence is common, and hospitalizations lead to extended sick leave. Women report feeling they are "treated differently" at work. Beyond physical limitations, the psychological toll of being ill for weeks or months compounds career harm. Returning to work after extended HG-related absence involves shame, anxiety about explaining the absence, and grief over career disruption.
Sources: IJGO 2025; Medscape; HER Foundation (employer guide)
💚 Psychological Treatment and Support
💚 Evidence-Based Therapeutic Approaches
EMDR (Eye Movement Desensitization and Reprocessing): In 4 out of 5 women with HG, a rapid response was achieved after just 1 to 2 sessions. EMDR can process traumatic memories and desensitize triggers for nausea and vomiting. No safety concerns have been identified with EMDR use during pregnancy.
CBT (Cognitive Behavioral Therapy): Evidence-based techniques for managing anxiety, building coping mechanisms, and maintaining psychological resilience. Recommended for high-risk pregnant women.
ACT (Acceptance and Commitment Therapy): Helps patients cope with difficult thoughts and emotions while maintaining commitment to values and action.
Peer Support: Reduces isolation and provides validation from women who have shared the experience. Can be delivered remotely (phone, video) for those unable to leave home.
Recovery Time: Physical recovery up to two years; psychological recovery sometimes longer. It is recommended to seek a therapist specializing in perinatal mental health.
Sources: Springer Publishing (EMDR); BJPsych Advances; EMDRIA; BMC Psychiatry 2024 (review)
📞 International Support Resources
Crisis Lines (Worldwide):
• Samaritans (UK & Ireland): 116 123
• Crisis Text Line (US, Canada, UK, Ireland): text HOME to 741741
• IASP Crisis Centers: find your country's line
International Organizations:
• HER Foundation (hyperemesis.org): education, support, research, free "Ready to COPE" app
• Pregnancy Sickness Support (UK): peer support network, expert advice, remote support
• COPE Australia: mental health and HG guide
💚 Documented Protective Factors
• Validation from medical staff: recognition that HG is a real, severe, and biologically grounded condition
• Partner and family support: active involvement in care and daily management
• Access to professional psychological care: therapist with perinatal specialization
• Peer support from HG survivors: support groups, online communities
• Adequate medical treatment of symptoms: including early access to medication
• Routine mental health screening: proactive assessment of mood and suicidal thoughts
• Workplace accommodations: employer flexibility during pregnancy and return to work
Future Pregnancies
Recurrence rates, prevention strategies, and planning ahead
📊 Recurrence Rates
HG recurs in 15% to 89% of subsequent pregnancies depending on study methodology. A prior history of HG is the strongest risk factor (RR 8.92). 40% of women delay a subsequent pregnancy. 52% did not become pregnant again, with two-thirds citing HG as the reason.
7 Prevention Strategies
Pre-Pregnancy Counseling
Review medical history and develop an early intervention plan with your care team before becoming pregnant.
Prophylactic Antiemetics
Starting Doxylamine/Pyridoxine immediately upon detecting pregnancy (before symptoms appear). An RCT demonstrated this reduces severity and duration.
Prenatal Multivitamins
Starting a multivitamin before or at the start of pregnancy may reduce the risk of severe nausea.
Metformin (New!)
6 or more months of metformin before pregnancy linked to over 70% risk reduction. Observational studies are promising; prospective trials are needed.
Optimal Nutritional Status
Optimize nutrition and physical condition before attempting pregnancy.
Early Monitoring
Arrange early prenatal follow-up for rapid intervention if symptoms begin.
Psychological Preparation
Establish support networks in advance: partner, family, mental health therapist, and support group.
Lifestyle & Management
Complementary therapies, rest, and daily management
Ginger
Systematic reviews and meta-analyses confirm ginger as an effective non-pharmacological treatment. Active compounds: gingerols and shogaols. Recommended dosing: 250 mg capsules 4 times daily, or ginger tea. Complements but does not replace medication in severe cases.
Acupressure
PC6 (Neiguan) point on the inner forearm above the wrist. Acupressure at PC6: 90% efficacy in one study. Manual pressure at the point: 63% efficacy (vs. placebo). SeaBand wristbands apply pressure to this point and are available over the counter.
Rest and Stress Reduction
Adequate rest and sleep. Reducing workload and stress. Lying down during severe episodes. Avoiding visual and olfactory triggers.
💡 Daily Tips
• Avoid strong smells and strongly-scented food
• Open windows for fresh air
• Ask for help with cooking and cleaning
• Drink in small sips throughout the day
• Prefer cold food (less odor)
• Keep dry snacks in every room
Stories & Support
Organizations, communities, and support groups
HER Foundation
The world's largest HG network. Online community, 7 Facebook groups, monthly Zoom meetings, individual support matching, helpline (833-2ChatHG-1), HG Care app, HELP Score assessment tools, and treatment protocols for healthcare providers. Website: hyperemesis.org
Pregnancy Sickness Support (UK)
The only UK charity dedicated to HG. National peer support network, expert advice, GP toolkit, helpline: 024 7638 2020. Website: pregnancysicknesssupport.org.uk
Hyperemesis Australia
Run by women who experienced HG. Volunteer support, closed Facebook communities, "You, Me & HG" podcast, pregnancy acknowledgment cards, free "Ready to COPE" mental health app. Website: hyperemesisaustralia.org.au
📚 Books
• "Hyperemesis Gravidarum — The Definitive Guide" (includes a section for partners)
• "The Chronicles of Nausea" by Ashli McCall
💬 Online Communities
• HER Foundation community (non-social media platform)
• Reddit: r/HyperemesisGravidarum
• Facebook groups (HER Foundation and independent groups)
• SOLVE HG Network (US-based advocacy and peer support)
Links & Resources
International organizations, key literature, and further reading
🌐 International Organizations
| Organization | Country / Region | Focus |
|---|---|---|
| HER Foundation | United States (Global) | Education, research funding, peer support, HELP Score, HG Care app, provider protocols |
| Pregnancy Sickness Support | United Kingdom | Peer support, expert advice, GP toolkit, EMERALD trial information |
| Hyperemesis Australia | Australia | Peer support, advocacy, "Ready to COPE" app, podcast, community |
| COPE Australia | Australia | Perinatal mental health, HG psychological guide for patients and clinicians |
🌐 Accessing Care Internationally
HG is recognized as a medical condition requiring treatment in all developed healthcare systems. In the UK, RCOG and NICE have published clinical guidelines for HG management. In the US, ACOG provides guidance. Antiemetic medications (including metoclopramide, ondansetron, and promethazine) are available in most countries. For hospitalization due to dehydration or weight loss, speak with your obstetrician or midwife. Home IV therapy programs exist in many countries as an alternative to inpatient admission.
🔭 Key Articles and Guidelines
🔭 Healthcare Provider Resources
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