Please note that all guidance is currently under review and some may be out of date. We recommend that you also refer to more contemporaneous evidence in the interim.
- 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:
- peptic ulcers
- 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.
- 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
- psychological interventions and emotional support
- behavioural interventions/modifications.
- 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
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.
Oral or IM or PR
TDS or QID
Caution - very sedating
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|
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
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|
|Assessment of hydration and electrolytes||
|Assessment of other pregnancy factors||
Admit to hospital and start IV rehydration if:
Consider any of:
If symptoms are still severe despite parenteral medication administration, consider corticosteroid administration:
|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.|
Refer to the dietitian:
|Enteral nutrition support||
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.
- rate of inpatient admission for hyperemesis
- adherence to standard of care.
For further information or assistance with auditing, please contact us via firstname.lastname@example.org
- 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.
Last updated 05 Nov 2018
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First published: October 2018
Last web update: October 2018
Review by: October 2020
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