OG9.6 | Hyperemesis Gravidarum — Summary & Reflection

KEY TAKEAWAYS

Hyperemesis gravidarum (HG) is the severe, pathological end of the nausea and vomiting of pregnancy spectrum, defined by weight loss >5% of pre-pregnancy body weight, ketonuria ≥2+, and electrolyte disturbance. It peaks with β-hCG at 8–10 weeks. Aetiology is multifactorial: β-hCG excess, oestrogen, H. pylori infection, and psychosocial factors. β-hCG cross-reacts with the TSH receptor, producing gestational transient thyrotoxicosis in up to 60% of cases — this does not require antithyroid treatment. Severity is quantified using the PUQE score (mild ≤6, moderate 7–12, severe ≥13).

Investigation includes urine dipstick, electrolytes, LFTs, TFTs, urine culture, and mandatory pelvic ultrasound to exclude molar pregnancy and multiple gestation. Complications include Wernicke's encephalopathy (thiamine deficiency → confusion + ophthalmoplegia + ataxia), Mallory-Weiss tears, electrolyte crises, venous thromboembolism, and fetal IUGR.

Management: (1) Thiamine 100 mg IV BEFORE any dextrose; (2) IV Hartmann's/saline with careful electrolyte correction; (3) antiemetic ladder: doxylamine-pyridoxine → promethazine/metoclopramide → ondansetron → corticosteroids (refractory); (4) thromboprophylaxis with LMWH; (5) nutritional support (enteral/parenteral if needed). Most women recover fully; severe prolonged HG can affect fetal growth.

REFLECT

Think back to a time when you encountered a patient — in a ward, a video, or a case scenario — who was seriously ill from something that should have been prevented. The sequence error in hyperemesis gravidarum (dextrose before thiamine) is exactly this kind of preventable harm: a common condition, a standard intervention, but a critical sequence that, when reversed, causes devastating neurological damage. Now that you understand why the sequence matters at the biochemical level, consider how you would explain this to a nursing colleague who asks "why are we giving an extra IV drug before the drip?" How would you make this principle unforgettable in your clinical practice? What mental safety check will you build for yourself every time you write a fluid order for a vomiting, malnourished patient?