Hyperemesis Gravidarum (HG)
Hyperemesis Gravidarum (HG) is a b-hCG related condition, therefore conditions that increase b-hCG will worsen the severity of HG. The main risk factor for this is an increased placental mass, which can be due to multiple pregnancies or molar pregnancy.
Multiple pregnancies is physiological therefore HG isn’t unexpected, but molar pregnancy is pathological and needs to be excluded
Other risk factors - First pregnancy, Overweight/obese, Hx or Family Hx
A rare, but important complication here is Wernicke’s encephalopathy as there could be a loss of Thiamine from the prolonged vomiting.
Diagnosis
For a diagnosis, it needs to occur in the 1st trimester (< 12 weeks), and other causes need to be excluded first. Its diagnositc criteria are:
Prolonged, persistent, severe N+V unrelated to other causes
If it occurs after 11/12 weeks and is less prolonged, other causes like gastroenteritis should be considered
Weight loss (>5% than pre-pregnancy weight)
Dehydration and electrolyte imbalance
The PUQE’s scoring system is used to assess its severity:
Management
N.B. Nothing given orally as the patient will be vomiting it all out.
Antiemetics - 1st lines are Cyclizine, Metoclopramide, Prochlorperazine
IVF w/Potassium
Thiamine to prevent Wernicke’s
N.B. Ginger has been shown to be useful in reducing symptoms.
An important side-effect to remember for Metoclopramide is acute dystonia (extra-pyramidal side-effect). Due to its antagonism at the D2 receptor, it can also cause block the extra-pyramidal circuits, leading to the side-effects of acute dystonia and tardive dyskinesia. This is same mechanism in which antipsychotics cause their side-effects.

