Hyperemesis Gravidarum (Severe Vomiting in Pregnancy)

Introduction

Hyperemesis gravidarum is a clinical situation in which vomiting in early
pregnancy considered to be physiological
becomes persistent or severe enough to
disturb the patient’s health and/or require hospitalization. This occurs in approximately a third to 50% of women
It is often the first sign of pregnancy,
beginning at about the 6 week and stops
spontaneously before the 14thweek.
Generally limited to the early morning, but may occur at other times of the day.
Cause is essentially unknown, but hypotheses include
Hormonal:

  • Increased sensitivity to placental
    hormones such as hCG, estrogen or
    progesterone.

Psychogenic:

  • The woman thinks she should have early morning sickness because generations before her have had it.

Clinical features

  • Persistent and severe vomiting that leads to electrolyte and nutritional derangements

Differential diagnoses

  • It is a diagnosis of exclusion.
  • Concerted effort must be made to exclude the under listed causes of pathological vomiting:
  • Multiple gestations
  • Hydatidiform mole
  • Malaria in pregnancy
  • Gastrointestinal disorders:
    • Heartburn due to hiatus hernia: a common
      cause of vomiting in late pregnancy
    • Enteritis
    • Appendicitis
    • Peptic ulcer disease
    • Hepatitis
    • Acute fatty liver of pregnancy
    • Pancreatitis
    • Cholecystitis
  • Urinary tract disorders:
    • pyelonephritis
  • Acute polyhydramnios
    • Commonly associated with monozygotic twinning and diabetic pregnancies
  • Pre-eclampsia
  • Accidents to ovarian cysts
  • Torsion, haemorrhage, infection and rupture
  • Red degeneration in a fibroid

Complications

  • Biochemical abnormalities
    • Usually sequel to vomiting, starvation and dehydration
    • Ketosis, electrolyte imbalance (alkalosis and hypokalemia); vitamin deficiencies
  • In neglected or poorly managed cases:
    • severe weight loss,
    • Tachycardia,
    • Hypotension,
    • Oliguria
  • Neurologic disorders from vitamin deficiency
  • Retinal haemorrhages
  • Jaundice (from hepatic necrosis)
  • Oesophageal tears and spontaneous rupture of the oesophagus
  • Mendelson’s syndrome
  • Fetal loss
  • Maternal mortality

Investigations

  • Full Blood Count with differentials
  • Urea, Electrolytes and Creatinine
  • Liver function tests
  • Midstream urine for microscopy culture and sensitivity
  • Urinalysis for ketones
  • Blood film for malaria parasites
  • Ultrasound scan of the pelvis/ abdomen to rule out multiple or abnormal pregnancies

Treatment

A. Mild cases

1st Line Treatment
Evidence Rating: [A]
Metoclopramide, oral, 10 mg 8-12 hourly
2nd Line Treatment
Evidence Rating: [A]
Promethazine theoclate, oral, 25 mg 8-12 hourly

Or

Promethazine hydrochloride, oral, 25 mg 8-12 hourly

B. Severe Cases

Normal saline, IV, (alternate with 5% Dextrose to meet requirements)

Or

Ringers lactate, IV, (alternate with 5% Dextrose to meet require ments)

And

1st Line Treatment
Evidence Rating: [A]
Metoclopramide, IM or IV,

  • 5-10 mg 8 hourly;
  • If body weight < 60 kg, give 5 mg 8 hourly.
  • Do not exceed 500 micro gram/kg in a day

2nd Line Treatment
Evidence Rating: [A]
Ondansetron, oral, IM, IV,

  • 4-8 mg 8 hourly as needed

3rd Line Treatment
Evidence Rating: [A]
Promethazine hydrochloride, IM or IV,

  • 25 mg 8-12 hourly (max. daily dose, 100 mg)
  • Total parenteral nutrition
  • In persistent and intractable cases with significant maternal complications, termination of pregnancy may be considered.

Referral Criteria

Refer severe cases with dehydration and/or shock and metabolic disturbances to a hospital for intravenous fluid replacement and antiemetic therapy.