Patient handout

Hyperemesis Gravidarum

PRODUCTION

1. Your condition

This handout is for hyperemesis gravidarum. Your care team identified this based on: persistent / intractable nausea and vomiting beginning in the first trimester not relieved by first-line oral antiemetics (acog pb 189).

Other reasons your team may use this plan: ≥ 5 % loss of prepregnancy body weight attributable to vomiting — defining hg criterion (acog pb 189; rcog gtg 69 2024); ketonuria on urine dipstick with clinical dehydration — supports hg vs mild-moderate nvp (acog pb 189); hypokalemia and/or hyponatremia (± hypochloremic metabolic alkalosis) in a vomiting first-trimester patient — electrolyte-derangement hg phenotype.

2. Your medications

Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.

Medication	Starting dose	How	When	What it does
pyridoxine	10-25 mg PO q6-8h	PO	q6-8h	ACOG PB 189 first-line; pyridoxine reduces nausea severity; well-tolerated; combine with doxylamine for added benefit
doxylamine	12.5 mg PO (with pyridoxine; up to QID, larger evening dose)	PO	q6-8h (often larger HS dose)	ACOG PB 189 first-line in fixed/loose combination with pyridoxine; Category A pregnancy safety; sedation is the main limiting effect

Plan: Hyperemesis gravidarum management axis — antiemetic ladder + rehydration/electrolytes + thiamine-before-dextrose + nutrition escalation (ACOG PB 189 + RCOG GTG 69 2024 + SOGC + Boelig Cochrane PMID 27091683)

3. When to call your provider

Contact your care team if any of the following happen:

Recurrent dehydration/ketonuria not controlled by day-case → admission
New Wernicke/neurologic features → urgent care + IV thiamine
Worsening mental-health crisis → urgent mental-health referral

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

Hyperemesis gravidarum — intractable first-trimester vomiting + ≥ 5 % prepregnancy weight loss + dehydration + ketonuria (± PUQE ≥ 13) → IV isotonic rehydration with KCl as needed, thiamine BEFORE any dextrose, antiemetic-ladder escalation, day-case vs admission per severity (ACOG PB 189; RCOG GTG 69 2024).
Wernicke-encephalopathy risk/features — prolonged HG vomiting (especially if dextrose/PN given without prior thiamine) OR confusion/ataxia/ophthalmoplegia → treatment-dose IV thiamine IMMEDIATELY and before any further dextrose; neurology + critical care (Chiossi 2006 PMID 16735862; RCOG GTG 69 2024).(life-threatening)
Electrolyte-derangement HG — hypokalemia (severe if < 2.5 mmol/L), hyponatremia, or hypochloremic metabolic alkalosis from protracted vomiting → monitored correction: KCl replacement with cardiac monitoring; correct hyponatremia CAUTIOUSLY to avoid osmotic demyelination (RCOG GTG 69 2024).
Refractory / nutrition-dependent HG — failure of optimised antiemetic ladder + rehydration → reassess corticosteroid eligibility (methylprednisolone ONLY if refractory and > 10 wk gestation) and escalate nutrition: enteral (NG/NJ) tube feeding → PPN/TPN as last resort; VTE prophylaxis while admitted (Boelig Cochrane PMID 27091683; ACOG PB 189; RCOG GTG 69 2024).
Gestational trophoblastic disease mimic — markedly elevated β-hCG and/or molar appearance on US with HG features → GTD pathway (uterine evacuation + post-molar β-hCG surveillance); HG typically resolves after evacuation (ACOG PB 189 differential).

5. Follow-up

Outpatient obstetric follow-up with continued/step-down antiemetics (most HG resolves by ~ 20 wk; a minority persist to term — plan a taper as tolerated). Nutrition / weight-recovery monitoring + dietitian follow-up. Mental-health screen (anxiety, depression, decisional regret, post-traumatic stress; consider EPDS) — HG carries a substantial psychological burden. Recurrence counseling: ~ 15-80 % in a subsequent pregnancy → preconception plan for early prophylactic pyridoxine ± doxylamine and early presentation. Thiamine repletion documented if any dextrose/parenteral nutrition was given. Re-check thyroid only if it had not normalised.

6. Sources

Guideline: ACOG Practice Bulletin 189 (2018, reaffirmed) Nausea and Vomiting of Pregnancy + RCOG Green-top Guideline 69 (2024) The Management of Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum + SOGC NVP Clinical Practice Guideline + ATA gestational thyroid guidance (gestational transient thyrotoxicosis) + Koren PUQE validation (PMID 16100620; PMID 12066075) + Boelig Cochrane interventions for HG (PMID 27091683) + Pasternak NEJM 2013 (PMID 23488728) + Huybrechts JAMA 2018 (PMID 30561479) ondansetron first-trimester safety + Chiossi Wernicke-in-HG systematic review (PMID 16735862)