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Hyperemesis Gravidarum (HG)

Hyperemesis gravidarum (HG) is severe nausea and vomiting of pregnancy that prevents normal eating or drinking and substantially limits daily life. It is more than ordinary pregnancy nausea. Dehydration, weight loss, electrolyte disturbance, and nutritional deficiency may occur, but a person does not need to meet one fixed weight-loss or laboratory threshold before receiving treatment.

Symptoms usually begin in the first trimester. Many people improve as pregnancy progresses, while others remain ill into the second or third trimester or until delivery.

Presentation

HG may involve:

  • prolonged nausea that leaves little or no symptom-free time;
  • repeated vomiting or retching;
  • inability to keep down ordinary food, fluids, or oral medication;
  • reduced urination, thirst, dizziness, fainting, rapid heart rate, or other signs of dehydration;
  • weight loss or inadequate pregnancy weight gain;
  • weakness, exhaustion, and inability to manage work or self-care;
  • intense food, smell, movement, or sensory triggers;
  • excessive saliva or difficulty swallowing saliva; and
  • anxiety, depression, isolation, or trauma responses arising from prolonged illness and dismissal.

The number of vomiting episodes does not capture the full severity. A person who is constantly nauseated, unable to drink, and barely able to move may be critically affected even during a period with less frequent vomiting.

Cause and risk

HG is a physiological pregnancy condition, not a sign of ambivalence about pregnancy, attention-seeking, or a psychiatric conversion disorder. Research has implicated growth differentiation factor 15 (GDF15), much of it produced by the fetoplacental unit, together with the pregnant person’s sensitivity to the hormone. The biology is still developing and does not yet provide a routine diagnostic test or an established preventive treatment.

Risk is higher after HG in an earlier pregnancy and in some multiple pregnancies. A twin pregnancy does not inevitably cause HG, and a singleton pregnancy can be severe. Family clustering and genetic associations also occur.

Assessment and diagnosis

Assessment considers when symptoms began, what the person can eat and drink, weight change, daily function, urination, medication tolerance, pain, bleeding, fever, neurological symptoms, and other medical conditions. Examination and testing may include vital signs, weight, blood tests, urine testing for infection or other concerns, and ultrasound when indicated.

Ketonuria can occur during poor intake but does not reliably measure dehydration or HG severity. Evaluation also considers other causes of vomiting, including infection, gastrointestinal or hepatobiliary disease, migraine, medication effects, endocrine or metabolic illness, and pregnancy-related conditions outside the ordinary NVP pattern.

Treatment

Treatment is individualized to symptoms, gestational age, medical history, and response. Early treatment can reduce dehydration and repeated emergency care. A person may need community care, ambulatory infusion treatment, home health support, hospital admission, or movement among those settings as severity changes.

Medication

Antiemetic treatment may use one medication or a combination from different classes. Options include doxylamine with pyridoxine, antihistamines, phenothiazines, metoclopramide, and ondansetron. Choice and sequencing depend on risks, benefits, prior response, route of administration, sedation, heart-rhythm considerations, and other adverse effects. Corticosteroids may be considered for refractory illness after standard options have failed.

When tablets cannot be retained, medication may be given as a dissolving preparation, suppository, injection, or intravenous infusion. Treatment should not be withheld simply because vomiting occurs early in pregnancy; untreated severe illness carries risks of its own.

Hydration, vitamins, and nutrition

Oral rehydration may be enough during less severe periods. Dehydration or inability to tolerate fluids may require intravenous fluid and electrolyte replacement. Prolonged vomiting increases the risk of thiamine deficiency; thiamine is given during significant or prolonged illness, particularly before dextrose-containing fluids or nutrition.

Nutrition care focuses first on what can be tolerated rather than an idealized pregnancy diet. Food temperature, texture, smell, timing, and brand may matter. When oral intake remains inadequate despite treatment, enteral nutrition may be considered. Parenteral nutrition carries substantial risks and is generally reserved for circumstances in which safer routes cannot meet the person’s needs.

People admitted with HG may also need assessment and prevention for venous thromboembolism, particularly when dehydration and immobility occur together.

Daily life and access

HG can make showering, dressing, cooking, traveling, speaking, or looking at a screen intolerable. Access may include remote appointments, a reduced schedule or leave from work, help with childcare and household tasks, fragrance control, a nearby bathroom or basin, permission to eat and drink whenever possible, low-stimulation spaces, and rapid access to infusion or obstetric care without repeatedly proving the illness from the beginning.

Caregivers may track medication and fluid tolerance, prepare small portions without pressure, manage scent triggers, keep emesis supplies within reach, and communicate changes to clinicians. Their role is support, not surveillance or coercion. The ill person remains the authority on which foods, smells, positions, and treatments are tolerable at a given moment.

Psychological care may be useful for the consequences of prolonged illness, fear, isolation, pregnancy loss concerns, or medical trauma. It does not replace physical treatment or imply that the vomiting is psychological.

Character histories

Ayana Brooks

Ayana Brooks developed severe HG early in her pregnancy with Ariana Landry and Adrian Landry, shortly after Elliot Landry completed fourteen months of cancer treatment. She was approximately forty-one or forty-two. She vomited repeatedly, struggled to keep down food and fluids, became profoundly depleted, and collapsed from dehydration more than once. Her pregnancy later also involved pre-eclampsia warning signs, bedrest, mobility limitations, and premature delivery; those complications were managed alongside the HG rather than treated as interchangeable with it.

Ayana’s OB/GYN training let her recognize the medical danger but did not make the illness easier to endure or manage alone. Elliot cared for her while still recovering from treatment until his own body could not sustain the full workload. Ava Keller then became Ayana’s primary additional support during the worst periods. Ava held her hair while she vomited, organized appointments and supplies, advocated when staff minimized her concerns, accompanied her after at least one dehydration collapse, and helped make prolonged bedrest and monitoring possible. The intimacy formed during that care developed into their romantic partnership.

Her course remained severe despite treatment and required repeated medical intervention and extensive daily support.

Patricia Matsuda

During her 1998 pregnancy with Lila Hayes, fifteen-year-old Pattie Matsuda experienced persistent severe nausea and vomiting described within her family as borderline HG. The symptoms continued into the second trimester, interfered with eating and daily function, and eased somewhat between approximately twenty and twenty-seven weeks without disappearing. Her pregnancy later developed severe preeclampsia and pulmonary edema and ended in an emergency cesarean delivery at thirty-one weeks.

Her family used “borderline HG” to describe this severe, persistent course. Ellen Matsuda, Susie Matsuda, and Evan Hayes supported her through food aversions, vomiting, exhaustion, and the loss of her ordinary ADHD medication and coping routines.

Ellen Matsuda

Ellen Matsuda had experienced borderline HG during pregnancy. Years later, that firsthand knowledge shaped the practical, nonjudgmental care she gave Pattie: she understood that persistence into the second trimester was possible and that reassurance about when symptoms “should” improve did not relieve the illness.

Historical context

For much of the twentieth century, clinicians often attributed HG to hysteria, ambivalence about pregnancy, family dynamics, or other psychological causes. Some institutions separated patients from family under the theory that attention reinforced vomiting. These frameworks delayed physical treatment and helped establish a culture in which severe pregnancy illness was minimized as ordinary morning sickness.

Antiemetic therapy, intravenous hydration, home and ambulatory care, nutrition support, and better recognition of thiamine deficiency changed management. The thalidomide disaster also produced lasting fear around medication use in pregnancy, making careful evidence and risk-benefit counseling especially important. Later genetic and hormonal research, including work on GDF15, further displaced the old psychosomatic explanation.

Metformin exposure before pregnancy has been studied as a possible way to alter GDF15 sensitivity, but current evidence does not establish it as routine HG prevention. It remains a research question rather than a standard recommendation.

Sources

  • American College of Obstetricians and Gynecologists. “Nausea and Vomiting of Pregnancy,” Practice Bulletin No. 189, reaffirmed guidance.
  • Royal College of Obstetricians and Gynaecologists. “The Management of Nausea and Vomiting in Pregnancy and Hyperemesis Gravidarum,” Green-top Guideline No. 69, second edition, 2024.
  • Fejzo, Marlena S., et al. “GDF15 linked to maternal risk of nausea and vomiting during pregnancy.” ‘’Nature’‘, 2023.
Medical Conditions Pregnancy Complications