Dehydration from prolonged vomiting in hyperemesis gravidarum leads to which electrolyte abnormality?

Dehydration from prolonged vomiting in hyperemesis gravidarum leads to which electrolyte abnormality?

• A. Hypocalcemia
• B. Hypomagnesemia
• C. Hyponatremia
• D. Hypernatremia

Answer: (D)

When dehydration results from vomiting, you lose water more than you lose sodium. That free-water loss concentrates the remaining fluid, raising the sodium concentration in the blood. In prolonged vomiting during hyperemesis gravidarum, this pattern commonly leads to hypernatremia rather than hyponatremia. While vomiting also causes loss of gastric acid and chloride (metabolic alkalosis), the electrolyte abnormality most directly linked to the dehydration itself is an elevated serum sodium. Hypocalcemia or hypomagnesemia aren’t typical for this scenario unless there are other nutritional or renal factors, and hyponatremia would stem from excess water relative to sodium, not from this dehydration pattern. Clinically monitor and rehydrate with fluids that restore volume and electrolyte balance carefully to avoid rapid shifts in sodium.