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Key messages

  • Nausea and vomiting affects up to 90 per cent of pregnancies.
  • Hyperemesis gravidarum (HG) is severe and persistent vomiting, usually with electrolyte abnormalities, ketosis and weight loss.
  • HG affects up to 3.6 per cent of pregnant women.
  • HG can have a profound effect on a woman's quality of life - early recognition and treatment is important.
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    In June 2023, we commenced a project to review and update the Maternity and Neonatal eHandbook guidelines, with a view to targeting completion in 2024. Please be aware that pending this review, some of the current guidelines may be out of date. In the meantime, we recommend that you also refer to more contemporaneous evidence.


    • Hyperemesis gravidarum (HG) is a severe form of nausea and vomiting, associated with dehydration, ketonuria and weight loss
    • HG affects 0.3-3.6 per cent of all pregnancies. It has emotional, physical and economic consequences for women and can lead to adverse outcomes such as low birth weight
    • HG starts before 22 weeks gestation
    • Aetiology is unknown.


    Exclude other pathological causes for nausea and vomiting, such as:

    • sepsis
    • peptic ulcers
    • cholecystitis
    • gastroenteritis
    • appendicitis
    • hepatitis
    • genitourinary, metabolic and neurological disorders
    • psychological causes, for example, spectrum of eating disorders
    • other pregnancy associated conditions, such as molar pregnancy.


    • The primary goal of treatment is symptomatic relief without adverse fetal or neonatal outcomes.
    • Secondary goals include improved quality of life and reduced economic costs for women.
    • Many pharmacological and non-pharmacological interventions are suggested for nausea and vomiting in pregnancy.
    • Small, frequent meals may be appropriate, but evidence for this advice is lacking.
    • Inform women of the potential for harm when using non-prescribed medications, particularly those containing unknown ingredients.

    Non-pharmacological interventions

    • Many women may perceive non-pharmacological interventions, or 'natural' remedies, as harmless.
    • The mechanism of action for many non-pharmacological interventions is poorly understood and evidence of benefit is limited and inconsistent.
    • Non-pharmacological interventions include:
      • dietary interventions
      • activity interventions
      • herbal remedies, such as ginger, chamomile, peppermint, raspberry leaf (after 32 weeks)
      • acupressure, acustimulation and acupuncture
      • relaxation techniques and hypnotherapy
      • homeopathic remedies
      • massage
      • psychological interventions and emotional support
      • behavioural interventions/modifications.

    Pharmacological interventions

    • Pharmacological interventions act by targeting specific receptors involved in nausea and vomiting.
    • Anticholinergics, antihistamines, dopamine antagonists, H3 antagonists and vitamins B6 may be used.
    • Combination therapy is more effective than trialling interventions one at a time.
    • Limited information is available on maternal and fetal adverse outcomes or psychological, social or economic outcomes.

    Table 1. Medications to treat hyperemesis

    Drug Dosage and administration Safety
    First line agents
    Pyridoxine (Vit B6)

    50 mg QID


    200 mg nocte

    Prochlorperazine (Stemetil)

    5–10 mg oral, up to QID


    25 mg oral/PR daily


    12.5 mg IV STAT

    Suppositories useful if oral route not tolerated
    Doxylamine (Restavit)  12.5 mg oral, nocte

    Caution - very sedating

    If needed, dose may be doubled.

    Promethazine (Phenergan)

    10–25 mg

    Oral or IM or PR

    TDS or QID

    Caution - very sedating

    Metoclopramide (Maxolon)

    10 mg oral, every eight hours

    Maximum dose 30 mg daily

    Maximum duration - 5 days

    To reduce the risk of neurological adverse events

    Second line agents
    Ondansetron (Zofran)

    4–8 mg, oral tablet or wafer

    BD or TDS

    Not on PBS
    Third line agents

    10–25 mg oral, 4–6 hourly


    50–100 mg PR, 6–8 hourly

    Anti-psychotic medication

    Avoid parenteral chlorpromazine

    Mirtazapine 7.5 mg nocte, gradually increasing to 15 mg nocte

    Caution - very sedating

    Hydrocortisone 100 mg IV, BD  
    Prednisolone 40–50 mg oral, daily  

    Outpatient management 

    Inpatient management

    Assessment of hydration and electrolytes
    • Mid-stream urine (MSU) and dipstick urinalysis for ketones
    • Urea, electrolytes and creatinine (UEC)
    • Liver function tests (LFTs)
    Assessment of other pregnancy factors
    • Ultrasound scan to identify possible causes such as multiple pregnancy, molar pregnancy, tumour
    • Thyroid function tests (TFTs)
    • Baseline weight

    Admit to hospital and start IV rehydration if:

    • dehydrated +/- ketotic
    • unable to tolerate fluids orally
    • refractory to oral anti-emetic treatment
    IV rehydration
    • Sodium chloride 0.9% is the most appropriate fluid replacement
    • Add potassium for replacement after checking electrolytes
    • A further treatment is multivitamin supplementation
    • Glucose solution should not be used unless the serum sodium levels are normal and thiamine supplementation has been prescribed to prevent Wernicke's encephalopathy
    • Usually, two or more litres of sodium chloride 0.9% is administered over 2-3 hours
    • If more fluid is needed, reassess hydration status
    • Ongoing IV rehydration may be needed two to three times a week
    Parenteral antiemetics

    Consider any of:

    • Metoclopramide 10 mg IM /IV 8-hourly (maximum of 30 mg daily). Caution: when administered IV inject slowly over 1-2 minutes. Rapid injection may cause a transient intense feeling of anxiety and restlessness followed by drowsiness.
    • Prochlorperazine 12.5 mg IM 8-hourly or 25 mg PR
    • Promethazine 12.5-25 mg IM 4-6 hourly (to maximum of 100 mg daily). Caution: Avoid IV route if possible as promethazine is highly caustic and may cause extravasation or intra-arterial injection may cause pain, paralysis, necrosis and gangrene. IV promethazine is only suitable in an emergency, using a large vein (not hand or wrist).
    • Ondansetron 4 mg IV/IM 8-hourly

    If symptoms are still severe despite parenteral medication administration, consider corticosteroid administration:

    • Hydrocortisone 100 mg BD until clinically improving
    • Then convert to Prednisolone 50 mg daily for three days:
      • then reduce to 25 mg daily for three days
      • then reduce dosage daily by 5 mg per day until lowest dose where symptoms are controlled
    • Corticosteroids should be administered with caution in women with abnormal blood glucose levels
    • With gastrointestinal upsets prophylactic ranitidine 150 mg bd (orally) may be needed
    Thiamine (Vit B1) Thiamine 100 mg orally or IV daily
    Holistic care Severe or prolonged symptoms may affect the woman’s quality of life. Assess each woman’s mental wellbeing and provide emotional, psychological or psychiatric support as appropriate.
    Dietitian referral

    Refer to the dietitian:

    • on diagnosis of HG where first and second line treatments do not appear to be effective
    • where weight loss in excess of 5 per cent of total body weight
    • HG refractory to parenteral medications to control nausea and vomiting
    Enteral nutrition support
    • If the woman does not respond to the above management interventions, they should be assessed by a dietitian to consider commencing short-term enteral feeding.
    • Small studies have shown enteral feeding is safe and effective in temporarily aiding fetal and maternal nutrition in severe HG.
    • Undertake a detailed nutritional assessment to determine the feeding regimen required.
    • Nausea and vomiting have been shown to improve within 24 hours after starting enteral feeding.
    • Insert an 8 french gauge nasogastric tube (NGT). Correct placement of the NGT must be determined prior to commencing enteral feeding.
    • Consider starting a continuous infusion of standard, iso-osmolar (for example, Osmolite, Jevity) formula at a rate of 20 mL/hr/day. Increase the rate by 10 mL/hr/day until the target rate as determined by the dietitian is achieved. Once the target rate is reached, consider delivering the total daily volume over 8–12 hours overnight.
    • Monitor closely for refeeding syndrome complications.
    • Discontinue enteral nutrition when 100 per cent of the woman’s nutritional needs are being met orally.
    • If enteral nutritional support is unsuccessful, trial parenteral nutrition. Total parental nutrition is a complex intervention. It should only be used as a last measure as it as it can be associated with serious complications.


    More information

    Audit and performance improvement

    All maternity services should have processes in place for:

    • auditing clinical practice and outcomes
    • providing feedback to clinicians on audit results
    • addressing risks, if identified
    • implementing change, if indicated.

    Auditable standards:

    • rate of inpatient admission for hyperemesis
    • adherence to standard of care.

    For further information or assistance with auditing, please contact us via


    • Abramowitz A, Miller ES, Wisner KL. Treatment options for hyperemesis gravidarum. Arch Womens Ment Health (2017) 20:363-372. DOI 10.1007/s00737-016-0707-4
    • Boelig RC, Barton SJ, Saccone G, Kelly AJ, Edwards SJ, Berghella V. Interventions for treating hyperemesis gravidarum. Cochrane Database of Systematic Reviews 2016, Issue 5. Art. No.: CD010607.DOI: 10.1002/14651858.
    • Mitchell-Jones N, Gallos I, Farren J, Tobias A, Bottomley C, Bourne T. Psychological morbidity associated with hyperemesis gravidarum: a systematic review and meta-analysis. BJOG 2017;124:20-30.
    • Royal College of Obstetricians and Gynaecologists (2016) The Management of Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum - Green-top Guideline no. 69.
    • Bay Bjorn AM, Ehrenstein V, Holmager Hundborg H, Aagaard Nohr E, Toft Sorensen H, Norgaard M. Use of corticosteroids in early pregnancy is not associated with risk of oral clefts and other congenital malformations in offspring. Am J Ther. 2012.
    • Edwards MJ, Agho K, Attia J, Diaz P, Hayes T, Illingworth A, et al. Case-control study of cleft lip or palate after maternal use of topical corticosteroids during pregnancy. Am J Med Genet A. 2003;120A(4):459-63.
    • Mygind H, Thulstrup AM, Pedersen L, Larsen H. Risk of intrauterine growth retardation, malformations and other birth outcomes in children after topical use of corticosteroid in pregnancy. Acta Obstet Gynecol Scand. 2002;81(3):234-9.

    Get in touch

    Clinical Guidance Team
    Safer Care Victoria

    Version history

    First published: November 2018
    Due for review: November 2021

    Uncontrolled when downloaded
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