Clinical Notes : Women's Health

16. Nausea and Vomiting in Pregnancy / Hyperemesis


Nausea and vomit in pregnancy:(NVP)

  • also known as morning sickness

  • 50-90% of pregnant women affected

  • Usual onset 6-8 weeks, peaks at 9 weeks, resolves by 12 weeks​

  • Good news :

    • women who experience NVP have been shown to have improved pregnancy outcomes. These include a decrease in miscarriages, pre-term deliveries, and stillbirths.

    • In addition, there is a lower prevalence for reduced fetal birth weight, fetal growth restriction, and fetal mortality

  • Hyperemesis gravidarum is the most severe form

    • < 1% of pregnancies.

    • Can be associated with twin pregnancies and adverse outcomes

    • characterised by persistent vomiting, volume depletion, ketosis, electrolyte disturbances, and weight loss.


  • Review symptoms, hydration, check urine for ketones

  • In cases of severe nausea and vomiting, esp. if onset is after 12 weeks gestation

    • exclude other causes

    • take an MSU

    • refer back to own GP for further investigation (blood tests and consider a pelvic ultrasound scan/ review by gynae)


Treatment without volume depletion

  • 1st line : conservative management

    • Encourage oral fluid intake

    • Small frequent meals with bland foods and avoid spicy, fatty odorous foods

    • Acupressure

    • Acupuncture

    • ginger 250 mg orally four times daily 

Treatment without volume depletion but failed conservative management

  • 1st line : pyridoxine and/or doxylamine

    • pyridoxine 10-25 mg orally three times daily

  • 2nd line : oral antihistamines or anri-emetics

    • primary options

      • Cyclizine (Valoid) 50mg tds

      • Metoclopramide (Maxolon) 5-10 mg orally every 8 hours when required for a maximum of 5 days, maximum 30 mg/day

      • Domperidone (Domerid, Motilium) 10 mg orally three times daily for a maximum of 7 days, maximum 30 mg/day

        • contraindicated in patients with severe hepatic impairment or underlying cardiac disease

        • should not be administered with other drugs that prolong the QT interval or inhibit CYP3A4

    • secondary options

    • Promethazine (Phenergan): 12.5 to 25 mg orally every 4-6 hours when required

    • Chlorpromazine (Clonactil) 10-25 mg orally every 4-6 hours when required

    • Prochlorperazine (Stemetil) 5-10 mg orally (immediate-release) every 6-8 hours when required

    • Ondansetron (Zofran) 4-8mg tds

Treatment with volume depletion (refer to A+E)

  • 1st line : intravenous hydration

  • Adjunct : parental or rectal antiemetics

  • Adjunct : proton-pump inhibitor alone or in conjunction with anti-emetic


  • Combination treatment with >1 antiemetic can be used

  • PPIs or H2 blockers are suggested as an adjunct in women who also have dyspepsia

Criteria for referral to secondary care

  • Volume depletion

  • Continued symptoms with ketonuria or >5% loss in body weight, despite oral antiemetics

  • Continued symptoms and unable to keep down oral antiemetics

  • Confirmed or suspected comorbidity eg UTI

BMJ Best Practice.png

Nausea and vomiting in pregnancy

BMJ Best Practice

March 2018


Antenatal care for uncomplicated pregnancies

NICE clinical guideline CG62

March 2008


Clinical Practice Guideline : Hyperemesis and nausea/vomiting in pregnancy

Institute of Obstetricians and Gynaecologists. Royal College of Physicians of Ireland

November 2018



Clinical Practice Guideline No.339 : The Management of Nausea and Vomiting in pregnancy

Society of Obstetricians and Gynaecologists of Canada.

December 2016



American Gastroenterological Association Institute Medical Position Statement on the Use of Gastrointestinal Medications in Pregnancy

Gartroenterology Volume 131, Issue 1, Pages 278–282

July 2006



Einarson A, Maltepe C, Boskovic R,  Koren G

Treatment of nausea and vomiting in pregnancy

Can Fam Physician. 2007 Dec; 53(12): 2109–2111.


Borrelli F, Capasso R, Aviello G, Pittler MH, Izzo AA.

Effectiveness and safety of ginger in the treatment of pregnancy-induced nausea and vomiting.

Obstet Gynecol. 2005;105(4):849–56


Thaver D, Saeed MA, Bhutta ZA.

Pyridoxine (vitamin B6) supplementation in pregnancy.

Cochrane Database Syst Rev. 2006;(2):CD000179


Ireland notes.png

The following medications are available in Ireland :

Cyclizine (Valoid)

Metoclopramide (Maxolon)

Domperidone (Domerid, Motilium) 

Promethazine (Phenergan)

Chlorpromazine (Clonactil) 

Prochlorperazine (Stemetil) 

Ondansetron (Zofran) 


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