HG Summary

Overview

  • Severe form of NVP affecting 0.3-3.6% pregnancies
  • Diagnosis of exclusion
  • Associated with high hCG levels
  • Peaks 9-16 weeks gestation

Diagnostic Criteria

  • Severe protracted nausea/vomiting
  • Weight loss >5% prepregnancy
  • Dehydration
  • Electrolyte imbalances
  • Ketosis

Risk Factors

  • Multiple pregnancy
  • Previous HG
  • Family history
  • First pregnancy
  • Obesity
  • H. pylori positive

Antiemetic Ladder

  • 1st line: Cyclizine, promethazine, prochlorperazine
  • 2nd line: Metoclopramide, domperidone, ondansetron
  • 3rd line: Specialist advice ± corticosteroids

Admission Criteria

  • Unable to keep down oral antiemetics
  • Ketonuria + weight loss >5%
  • Suspected comorbidity
  • Dehydration despite oral treatment

Key Investigations

  • Urine dipstick (ketones)
  • U&E, FBC, LFTs
  • Ultrasound scan
  • TFTs, amylase if refractory

Critical Management

  • IV fluids + potassium
  • Thiamine supplementation
  • Thromboprophylaxis (LMWH)
  • Daily electrolyte monitoring

Hyperemesis Gravidarum (HG)

Severe nausea and vomiting in pregnancy requiring comprehensive management

Overview

Nausea and vomiting of pregnancy (NVP) affects up to 80% of pregnant women, with about 35% having clinically significant symptoms. Hyperemesis gravidarum (HG) is the severe form of NVP, affecting about 0.3–3.6% of pregnant women.

Timeline: NVP usually begins between 4th-7th weeks of gestation, peaks between 9th-16th weeks, and resolves by around 20th week of pregnancy.

Pathophysiology

NVP is primarily associated with rising levels of beta human chorionic gonadotrophin (hCG). Conditions with higher hCG levels, such as trophoblastic disease and multiple pregnancy, are associated with increased severity of NVP.

Risk Factors

Pregnancy-related

  • Increased placental mass (molar gestation, multiple gestation)
  • First pregnancy
  • History of HG in previous pregnancies
  • Family history (first-degree relatives) of NVP

Patient Factors

  • History of motion sickness
  • History of migraines
  • History of nausea with estrogen-containing oral contraceptives
  • Obesity
  • Stress
  • Seropositive for Helicobacter pylori

Clinical Features

Hyperemesis gravidarum is a diagnosis of exclusion characterized by:

Core Diagnostic Features

  • Severe, protracted nausea and vomiting
  • Weight loss of more than 5% of prepregnancy weight
  • Dehydration
  • Electrolyte imbalances
  • Ketosis

Associated Symptoms

  • Hypersalivation (ptyalism)
  • Food aversions
  • Fatigue and weakness
  • Decreased urine output

Complications

Metabolic Complications

  • Weight loss and malnutrition
  • Dehydration
  • Hyponatremia or hypokalemia
  • Hypochloremic metabolic alkalosis (severe cases: metabolic acidemia)
  • Abnormal liver function tests
  • Vitamin deficiencies (especially thiamine - risk of Wernicke's encephalopathy)

Mechanical Complications

  • Retinal hemorrhage
  • Splenic avulsion
  • Mallory-Weiss tears or esophageal rupture
  • Pneumothorax or pneumomediastinum

Serious Complications

  • Venous thromboembolism (immobility + dehydration)
  • Wernicke's encephalopathy (thiamine deficiency)
  • Maternal death (rare)

Differential Diagnosis

Other pathological causes of nausea and vomiting must be excluded:

Category Conditions
Gastrointestinal Peptic ulcers, cholecystitis, gastroenteritis, hepatitis, pancreatitis, appendicitis
Genitourinary Urinary tract infection, pyelonephritis, nephrolithiasis
Metabolic Diabetic ketoacidosis, hyperthyroidism, Addison's disease
Neurological Migraine, increased intracranial pressure
Drug-induced Various medications, iron supplements
Pregnancy-related Acute fatty liver of pregnancy, pre-eclampsia

Investigations

Essential Investigations

Urine Tests

  • Urine dipstick: Quantify ketonuria as 1+ ketones or more
  • Urine culture: Exclude infection

Blood Tests

  • Urea and electrolytes: Hypokalemia/hyperkalemia, hyponatremia, dehydration, renal disease
  • Full blood count: Infection, anemia, raised hematocrit
  • Blood glucose monitoring: Exclude diabetic ketoacidosis if diabetic

Imaging

Ultrasound scan: Confirm viable intrauterine pregnancy, exclude multiple pregnancy and trophoblastic disease

Additional Investigations (Refractory Cases)

Test Purpose
Thyroid function tests Exclude hyperthyroidism/hypothyroidism
Liver function tests Exclude other liver disease, monitor malnutrition
Calcium and phosphate Metabolic assessment
Amylase Exclude pancreatitis
Arterial blood gas Exclude metabolic disturbances, monitor severity

Management

Antiemetic Therapy

Stepwise Approach
  1. First-line: Oral cyclizine or promethazine (antihistamines), prochlorperazine or chlorpromazine (phenothiazines), or doxylamine/pyridoxine (Xonvea®). Reassess after 24 hours.
  2. Second-line: If first-line ineffective, switch to oral metoclopramide or domperidone (dopamine antagonists), or ondansetron (5-HT3 antagonist). Reassess after 24 hours.
  3. Third-line: If second-line ineffective, seek specialist advice. Consider corticosteroids.

Setting of Care

Community Management

  • Women with vomiting but no dehydration
  • Antiemetics, support, reassurance
  • Oral hydration and dietary advice
  • Small frequent meals, dry carbohydrates

Ambulatory Daycare

  • When community measures fail
  • Parenteral fluids and antiemetics
  • Parenteral vitamins (multi and B-complex)
  • Regular monitoring

Inpatient Management

  • Continued nausea/vomiting + inability to keep down oral antiemetics
  • Ketonuria and/or weight loss >5% despite oral antiemetics
  • Confirmed/suspected comorbidity
  • Severe dehydration

Inpatient Management Protocol

Critical Interventions for Hospitalized Patients:

Intervention Details
IV Fluids Normal saline with potassium chloride, guided by daily electrolyte monitoring
Monitoring Daily U&E, fluid balance, weight
Thiamine Supplementation (oral/IV) for all admitted women, especially before dextrose/parenteral nutrition
Thromboprophylaxis LMWH unless contraindicated (discontinue on discharge)
GI Protection H2 receptor antagonists or PPIs for GERD/esophagitis/gastritis

Refractory Cases

When all other medical therapies have failed, consider enteral or parenteral nutrition with multidisciplinary approach involving obstetricians, gastroenterologists, and dietitians.

Patient Education and Support

Dietary Advice

  • Small, frequent meals (every 1-2 hours)
  • Dry carbohydrates (crackers, toast) before rising
  • Cold foods (better tolerated than hot)
  • Avoid triggers (strong smells, fatty foods)
  • Separate fluids from solids

Lifestyle Modifications

  • Adequate rest
  • Stress reduction techniques
  • Ginger supplements (evidence varies)
  • Acupressure bands

Psychological Support

  • Reassurance about condition
  • Counseling if needed
  • Support groups
  • Partner/family education