HYPEEREMESIS GRAVIDARUM

SWARAJ HOSPITAL & RESEARCH INSTITUTE

BOLANGIR, ODISHA  •  OBSTETRICS & GYNAECOLOGY CLINICAL PATHWAY SERIES

Clinician Reference Infographic

Hyperemesis Gravidarum — Assessment, Treatment & Warning Signs

Hyperemesis gravidarum is severe, persistent vomiting in early pregnancy that causes dehydration, weight loss and electrolyte disturbance. The pathway is to grade it, exclude other causes, replace fluids and thiamine, and escalate antiemetics in steps — while watching for the dangerous complication, Wernicke's encephalopathy.

🎯 AT A GLANCE — NVP VERSUS HYPEREMESIS

Nausea and vomiting of pregnancy (NVP) affects 70–80% of pregnancies; it starts around 4–6 weeks, peaks at about 9 weeks, and settles by 16–20 weeks in most

Hyperemesis gravidarum (HG) is the severe end — about 0.3–3% of pregnancies: persistent vomiting with weight loss over 5% of pre-pregnancy weight, dehydration (ketonuria) and electrolyte disturbance

About 1 in 10 women with HG continue to vomit until delivery

HG is not “just morning sickness”. It is a serious, treatable condition that can cause Wernicke's encephalopathy, loss of work and mental-health harm — treat early and take the woman seriously.

🧬 WHY IT HAPPENS — AND WHO IS AT RISK

Mechanisms

hCG peaks at 9–12 weeks, matching the timing of symptoms

GDF15 — a hormone made by the placenta that acts on the brainstem; maternal sensitivity to it decides severity

Oestrogen, progesterone and slowed gastric emptying add to the load

Transient thyroid stimulation in many (see work-up)

Risk Factors

Previous HG or a mother or sister with HG

Multiple pregnancy and molar pregnancy (high hCG)

Nulliparity, young age, obesity or a history of migraine and motion sickness

Smoking lowers the risk

🔎 BEFORE LABELLING IT HG — EXCLUDE OTHER CAUSES

Typical HG: starts before 9 weeks, comes without fever, severe pain or headache, and with a normal abdomen

Think again if: vomiting begins after 9–10 weeks, or there is abdominal pain, fever, diarrhoea, headache, neck stiffness, or urinary symptoms

Gastrointestinal: gastroenteritis, hepatitis, pancreatitis, cholecystitis, appendicitis, peptic ulcer

Urinary and metabolic: UTI or pyelonephritis, diabetic ketoacidosis, hyperthyroidism, Addison's disease

Pregnancy-related: multiple pregnancy and molar pregnancy — an early ultrasound is part of the work-up (see our GTD guide)

📏 ASSESS SEVERITY — THE PUQE SCORE

In the last 12 hours	1	2	3	4	5
Hours of nausea	None	≤ 1	2–3	4–6	> 6
Episodes of vomiting	None	1–2	3–4	5–6	≥ 7
Episodes of retching	None	1–2	3–4	5–6	≥ 7

Mild: total score ≤ 6

Moderate: total score 7–12

Severe: total score ≥ 13 — consider admission

Also record: weight against pre-pregnancy weight, hydration, pulse, blood pressure, and ketones on urine dipstick. Repeat at every visit.

🔬 INVESTIGATIONS

1

Urine ketones and urinalysis with culture

2

Urea, creatinine and electrolytes — look for low potassium, low sodium and a metabolic alkalosis; add magnesium, calcium and phosphate if admitted

3

Full blood count, glucose, and liver function (mildly raised transaminases are common)

4

TSH and free T4 — frequently shows transient hyperthyroidism; treat only if clinical thyrotoxicosis is present

5

Ultrasound to confirm viability and exclude molar or multiple pregnancy

6

Amylase or lipase, and blood gas if there is pain or severe illness

📈 STEPWISE MEDICAL TREATMENT

Step 1 — LifestyleSmall, frequent, bland or cold meals; avoid triggers such as strong smells; ginger and P6 acupressure may help; take iron-containing vitamins at night or pause them

Step 2 — First-line drugsPyridoxine (vitamin B6) 10–25 mg three to four times daily, with or without doxylamine; or an antihistamine: promethazine 12.5–25 mg every 4–6 h, or cyclizine 50 mg three times daily

Step 3 — Second-line drugsMetoclopramide 5–10 mg three times daily, or prochlorperazine; ondansetron 4–8 mg every 8 h if still vomiting (small possible first-trimester risk; may cause constipation or QT prolongation)

Step 4 — RefractoryCorticosteroids (hydrocortisone 100 mg IV twice daily, then oral prednisolone tapered) only after 10 weeks; other options include mirtazapine or gabapentin, with specialist advice

Combine drugs from different classes when one fails, and use the oral, rectal, or parenteral route that the woman can keep down

Add a PPI or H2 blocker for reflux; treat constipation, which makes nausea worse

Doses are typical adult doses. Always check local formulary and the individual's QT risk, other drugs, and kidney function.

🏥 WHEN TO ADMIT — AND WHAT INPATIENT CARE INVOLVES

Admit if: PUQE ≥ 13, persistent vomiting with ketonuria despite oral antiemetics, weight loss over 5%, electrolyte disturbance, an inability to keep down fluids or medicines, or a coexisting condition such as diabetes

Day-care or ambulatory IV therapy works for many moderate cases and avoids full admission

IV fluidsIsotonic saline or Hartmann's with potassium added to correct deficits; monitor sodium and avoid rapid correction

ThiamineGive thiamine before any dextrose-containing fluid — 100 mg IV daily during admission, or oral thiamine 100 mg daily when vomiting settles

ElectrolytesReplace potassium, magnesium and phosphate; correct hyponatraemia slowly to avoid osmotic demyelination

ThromboprophylaxisLMWH for admitted women, with compression stockings and early mobilisation, because dehydration and immobility raise VTE risk

NutritionRefractory cases: nasogastric or nasojejunal feeding, or parenteral nutrition as a last resort; watch for refeeding syndrome

🚨 WERNICKE'S ENCEPHALOPATHY — A MEDICAL EMERGENCY

Suspect it in any woman with prolonged vomiting who develops confusion, drowsiness, unsteady gait, double vision, nystagmus, or ophthalmoplegia — the full triad is rare

Treat at once with IV thiamine, 200–500 mg three times daily, before any glucose; do not wait for the scan or the blood test

Replace magnesium, correct the electrolytes, and seek urgent neurology and critical-care advice

Untreated, it leaves permanent memory loss (Korsakoff syndrome) or death — and the fetus is at risk

⚠️ COMPLICATIONS

Maternal

Wernicke's encephalopathy (thiamine deficiency)

Hypokalaemia, hyponatraemia, and metabolic alkalosis

Mallory–Weiss tear, and rarely oesophageal rupture

VTE, vitamin K deficiency with bleeding, and refeeding syndrome

Depression, anxiety and traumatic stress

Fetal / Neonatal

Weight loss over 5% is linked to low birth weight and preterm birth

Most babies are healthy when HG is treated well

Folate, iron, and vitamin deficiencies need prevention

Prolonged severe cases need growth scans

💛 COUNSELLING, SUPPORT & FUTURE PREGNANCIES

Recognise the burden: HG can cause isolation, job loss, and thoughts of termination; ask about mood and offer psychological support

Reassure: antiemetics at standard doses have wide safety data, and untreated HG carries more risk than most treatments

Most women improve by 16–20 weeks, though some need treatment to term

Recurrence is common (often more than half of later pregnancies) — offer pre-emptive antiemetics and early review in the next pregnancy, ideally starting before symptoms begin

Termination of pregnancy is considered only in severe, refractory cases after full counselling and specialist input

⛔ WHAT NOT TO DO

Do not dismiss her as having “morning sickness” — early treatment prevents admission

Do not give dextrose before thiamine in a vomiting woman

Do not correct sodium quickly, and do not give steroids before 10 weeks

Do not treat transient biochemical hyperthyroidism with antithyroid drugs unless there is true thyrotoxicosis

Do not withhold safe antiemetics from fear of birth defects — discuss the evidence

Memory Aid

HYPER

Five habits for every woman with severe vomiting in pregnancy.

H

Hydrate — isotonic IV fluids with potassium, and replace electrolytes

Y

Yield to a stepwise antiemetic plan — B6 and antihistamines first, then add and escalate

P

PUQE score, weight, and urine ketones — score her at every visit

E

Exclude other causes and examine for molar or multiple pregnancy

R

Replace thiamine before dextrose, and suspect Wernicke's in any confusion

Remember: early, adequate treatment shortens the illness, protects the brain, and spares the mother a long admission.

Swaraj Hospital & Research Institute · Department of Obstetrics & Gynaecology, Bolangir, Odisha

Clinician-facing summary based on ACOG and RCOG guidance; drug choice, doses and availability vary by country and formulary — follow local protocol and individualise care.