HYPEREMESIS GRAVIDARUM

What is the typical timeline for nausea and vomiting of pregnancy (onset, peak, and resolution)?

Starts at 5 weeks, peaks at 8-10 weeks, and typically disappears by 16-18 weeks.

Which obstetric conditions are most commonly associated with Hyperemesis Gravidarum due to markedly high hCG?

Complete molar pregnancy and multiple gestations.

What is the mechanism by which severe HG causes transient hyperthyroidism?

The beta subunits of hCG mimic TSH and bind to TSH receptors, causing suppressed TSH and high fT4 in over 60% of severe cases.+1

How can you clinically differentiate the hyperthyroidism of HG from true primary hyperthyroidism (like Graves' disease)?

In HG, there are no eye signs or goiter, the tachycardia responds to IV rehydration, and there is an absence of thyroid autoantibodies.

What is the required weight loss threshold to support a diagnosis of Hyperemesis Gravidarum?

Weight loss of more than 5% of pre-pregnancy weight.

What is an early and important urinary finding that alerts a physician to severe dehydration and malnutrition in HG?

Ketonuria (indicates a shift to fat metabolism/starvation).

What is the classic acid-base and electrolyte disturbance seen in severe Hyperemesis Gravidarum?

Metabolic alkalosis accompanied by hyponatremia, hypokalemia, and hypochloremia.+1

What severe neurological complication is caused by Vitamin B1 (Thiamine) deficiency in HG, and what is a major iatrogenic trigger?

Wernicke's encephalopathy. It can be precipitated by giving carbohydrate-containing foods or fluids (like IV Dextrose) before replacing thiamine.

What are the classic clinical signs of Wernicke's encephalopathy?

Confusion/memory problems, gait ataxia/unsteadiness, and ocular abnormalities (nystagmus, ophthalmoplegia, 6th nerve palsy).

Why must hyponatremia be corrected slowly in a patient with HG?

To avoid osmotic demyelination syndrome (Central pontine myelinolysis), which can cause lethargy and seizures.

What is the initial IV fluid of choice for resuscitation in HG, and which fluid is strictly inappropriate?

Give Normal Saline or Ringer Lactate initially. IV fluids containing dextrose are inappropriate.

What is the usual first-line medical treatment for nausea and vomiting in pregnancy?

Doxylamine-pyridoxine (an antihistamine combined with Vitamin B6).

Why is there caution regarding the use of Ondansetron before 10 weeks of gestation?

Potential risks of congenital defects should be considered.

According to past papers, is Hyperemesis Gravidarum associated with grand multiparity?

No. Grand multipara is associated with big babies, PPH, APH, and operative deliveries, but not hyperemesis.

Should you prescribe anti-thyroid medications to treat the transient hyperthyroidism associated with HG?

No. There is no place for anti-thyroid medication; fT4 levels usually fall to normal and TSH escapes suppression by 19 weeks.+1