Questionnaire/history:

Nausea?

Vomiting?

Hyperemesis gravidarum (HG)?

- Protracted nausea and vomiting in pregnancy?

- 5% pregnancy weigh loss?

- Dehydration?

- Electrolyte imbalance?

Red flags?

- Impaired renal function?

- Severe electrolyte disturbance?

- Cognitive effects consistent with Wernicke’s or central pontine myelinosis?

- Indication of suicidal ideation?

(Notes: Consider psychological aspect of nausea and vomiting in pregnancy (up to 20% develop PTSD symptoms)

Symptoms peak at 9-11 weeks and resolve in most by 16-20 weeks; early treatments may appear to become ineffective but it is actually the condition getting worse and additional treatment may be required)

Past medical history?

Current medication?

Known drug allergies?

Investigations:

Urine dipstick (1+ ketones counts as ketonuria)?

MSU?

(Note: BMJ reports data showing ketonuria is an unreliable marker)

FBC?

U&E?

Blood glucose?

USS: to confirm viable intrauterine pregnancy, exclude multiple pregnancy and trophoblastic disease (can be done routinely if the women respond to initial treatment)?

Management:

Ginger and acupressure/puncture safe and may improve mild symptoms

Drug options

1st line:

Prochlorperazine 5-10 mg 6-8 hourly PO; 12.5mg 8 hourly IM/IV; 25mg PR daily

Promethazine 12.5-25 mg 4-8 hourly PO, IM, IV or PR

Chlorpromazine 10-25 mg 4-6 hourly PO, IV or IM; 50-100mg 6-8 hourly PR

2nd line:

Metoclopramide 5-10 mg 8 hourly PO, IV or IM (max. 5 days duration)

(Note: extrapyramidal symptoms and oculogyric crisis can occur with phenothiazines and metoclopramide)

Domperidone 10 mg 8hrly PO; 30-60mg 8 hourly PR (Note: not recommended by NICE)

(Note: small increased risks of cleft palate (3 extra cases/10,000 births) if used. In 1st trimester, data on cardiac defects reassuring)

Ondansetron 4-8 mg 6-8 hourly PO; 8mg over 15min 12hrly IV

3rd line:

Hydrocortisone IV BD initially then convert to prednisolone 40-50mg daily PO once clinical improvement occurs (secondary care led)

Doxylamine/pyridoxine:

Only licensed product for NVP but no good evidence it is more effective than well-established (unlicensed) treatments and is expensive, less effective than ondansetron

Consider treating reflux (in 80% with severe NVP): PPIs appropriate

Admission if:

Continued nausea and vomiting and inability to keep down oral antiemetics, ketonuria and/or weight loss > 5% despite oral antiemetics, red flags or if confirmed or suspected comorbidities

Resource(s):

BMJ 2018

RCOG 2016

MHRA 2020

NICE NG210