Nausea and vomiting in pregnancy
- Overview
- Theory
- Diagnosis
- Management
- Follow up
- Resources
Treatment algorithm
Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer
without volume depletion
conservative management
Dietary modifications may include advice to eat smaller, more frequent meals and to avoid smells and food textures that cause nausea.[2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy
Foods should be bland-tasting, high in carbohydrate, and low in fat. Salty foods may be tolerated early in the morning. Sour and tart liquids (e.g., lemonade) are often better tolerated than water. Eliminating supplemental iron, and substituting folic acid for iron-containing prenatal vitamins, may improve symptoms of nausea.[2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy
If dietary modifications fail to improve symptoms, various alternative treatments (e.g., acupressure, acupuncture, ginger) have been evaluated in the treatment of NVP, and may be tried. Since there have been no head-to-head comparisons of the majority of these modalities, it is difficult to recommend a first-line treatment. Patients should be apprised of the various options and encouraged to try the one that they would prefer.
Acupressure may improve symptoms.[2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy [15]Matthews A, Haas DM, O'Mathúna DP, et al. Interventions for nausea and vomiting in early pregnancy. Cochrane Database Syst Rev. 2015;(9):CD007575. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD007575.pub4/full http://www.ncbi.nlm.nih.gov/pubmed/26348534?tool=bestpractice.com Pressure is applied to the P6 point (Neiguan point, located 3 finger-widths above the wrist on the volar surface). This may be applied using commercially available wrist bands.
Ginger supplementation has also been shown to be useful in reducing symptoms.[2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy [15]Matthews A, Haas DM, O'Mathúna DP, et al. Interventions for nausea and vomiting in early pregnancy. Cochrane Database Syst Rev. 2015;(9):CD007575. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD007575.pub4/full http://www.ncbi.nlm.nih.gov/pubmed/26348534?tool=bestpractice.com [16]McParlin C, O'Donnell A, Robson SC, et al. Treatments for hyperemesis gravidarum and nausea and vomiting in pregnancy: a systematic review. JAMA. 2016 Oct 4;316(13):1392-401. http://www.ncbi.nlm.nih.gov/pubmed/27701665?tool=bestpractice.com It may be used alone or with acupressure and is considered safe to use in all trimesters of pregnancy. It can be taken raw, as a tea, or in tablet/capsule form.[17]Ding M, Leach M, Bradley H. The effectiveness and safety of ginger for pregnancy-induced nausea and vomiting: a systematic review. Women Birth. 2013 Mar;26(1):e26-30. http://www.ncbi.nlm.nih.gov/pubmed/22951628?tool=bestpractice.com [18]Thomson M, Corbin R, Leung L. Effects of ginger for nausea and vomiting in early pregnancy: a meta-analysis. J Am Board Fam Med. 2014 Jan-Feb;27(1):115-22. https://www.jabfm.org/content/27/1/115.long http://www.ncbi.nlm.nih.gov/pubmed/24390893?tool=bestpractice.com
Primary options
ginger (Zingiber officinale): 250 mg orally four times daily
More ginger (Zingiber officinale)Considered safe in pregnancy.
without volume depletion but failed conservative management
pyridoxine and/or doxylamine
If nonpharmacologic methods fail, first-line pharmacologic therapies include pyridoxine (vitamin B6) and doxylamine (an antihistamine).[2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy One randomized controlled trial found that the combination was effective compared with placebo, but a re-analysis of the data queried the clinical significance of the findings.[19]Koren G, Clark S, Hankins GD, et al. Effectiveness of delayed-release doxylamine and pyridoxine for nausea and vomiting of pregnancy: a randomized placebo controlled trial. Am J Obstet Gynecol. 2010 Dec;203(6):571.e1-7. http://www.ncbi.nlm.nih.gov/pubmed/20843504?tool=bestpractice.com [20]Persaud N, Meaney C, El-Emam K, et al. Doxylamine-pyridoxine for nausea and vomiting of pregnancy randomized placebo controlled trial: prespecified analyses and reanalysis. PLoS One. 2018 Jan 17;13(1):e0189978. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0189978 http://www.ncbi.nlm.nih.gov/pubmed/29342163?tool=bestpractice.com These drugs may be used alone or in combination, and are available as a proprietary combination formulation in some countries, including the US. Doxylamine alone is currently only available in formulations marketed as sleeping aids in the US.
Both drugs are considered safe during all trimesters of pregnancy.[2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy
Primary options
pyridoxine (vitamin B6): 10-25 mg orally three times daily
More pyridoxine (vitamin B6)Considered safe in pregnancy.
and/or
doxylamine: 12.5 mg orally every 6-8 hours when required
More doxylamineConsidered safe in pregnancy.
OR
doxylamine/pyridoxine: 20 mg/20 mg (2 tablets) orally (delayed-release) once daily at bedtime on day 1, increase gradually according to response, maximum 40 mg/40 mg (4 tablets)/day
More doxylamine/pyridoxineEach tablet contains 10 mg of doxylamine and 10 mg of pyridoxine.
Considered safe in pregnancy.
oral antihistamines or antiemetics
Second-line pharmacologic therapies include alternative oral antihistamines (e.g., meclizine, dimenhydrinate, diphenhydramine), phenothiazine antiemetics (e.g., chlorpromazine, prochlorperazine), or dopamine antagonist antiemetics (e.g., metoclopramide, domperidone).[2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy [21]Leathem A. Safety and efficacy of antiemetics used to treat nausea and vomiting in pregnancy. Clin Pharm. 1986 Aug;5(8):660-8. http://www.ncbi.nlm.nih.gov/pubmed/2874910?tool=bestpractice.com [22]Gill SK, O'Brien L, Koren G. The safety of histamine 2 (H2) blockers in pregnancy: a meta-analysis. Dig Dis Sci. 2009 Sep;54(9):1835-8. http://www.ncbi.nlm.nih.gov/pubmed/19051023?tool=bestpractice.com Domperidone is not currently available in the US.
Metoclopramide should be used for up to 5 days only in order to minimize the risk of neurologic and other adverse effects.[38]European Medicines Agency. European Medicines Agency recommends changes to the use of metoclopramide. Jul 2013 [internet publication]. https://www.ema.europa.eu/en/news/european-medicines-agency-recommends-changes-use-metoclopramide
Primary options
meclizine: 25 mg orally every 4-6 hours when required, maximum 100 mg/day
More meclizineConsidered safe in pregnancy.
OR
dimenhydrinate: 50-100 mg orally every 4-6 hours when required, maximum 400 mg/day
More dimenhydrinateConsidered safe in pregnancy.
OR
diphenhydramine: 25-50 mg orally every 4-6 hours when required, maximum 300 mg/day
More diphenhydramineConsidered safe in pregnancy.
OR
metoclopramide: 5-10 mg orally every 8 hours when required for a maximum of 5 days, maximum 30 mg/day
More metoclopramideConsidered safe in pregnancy.
Secondary options
chlorpromazine: 10-25 mg orally every 4-6 hours when required
More chlorpromazineUse only if maternal benefits outweigh risks to fetus.
OR
prochlorperazine maleate: 5-10 mg orally (immediate-release) every 6-8 hours when required
More prochlorperazine maleateUse only if maternal benefits outweigh risks to fetus.
OR
promethazine: 12.5 to 25 mg orally every 4-6 hours when required
More promethazineUse only if maternal benefits outweigh risks to fetus.
Tertiary options
trimethobenzamide: 300 mg orally every 6-8 hours when required
More trimethobenzamideUse only if maternal benefits outweigh risks to fetus.
with volume depletion
intravenous hydration
Patients with severe volume depletion should be rehydrated with intravenous Ringer lactate. If Ringer lactate is not available, saline solutions can be used, with additional potassium and sodium bicarbonate as necessary.
Glucose solutions may be used. If solutions containing glucose are considered, some physicians suggest also giving thiamine (vitamin B1) prior to administration in order to prevent Wernicke encephalopathy.[1]Goodwin TM. Hyperemesis gravidarum. Clin Obstet Gynecol. 1998 Sep;41(3):597-605. http://www.ncbi.nlm.nih.gov/pubmed/9742356?tool=bestpractice.com [2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy
Intravenous fluids should be given to replace the calculated deficit, ongoing losses, and the daily fluid maintenance requirement. Volume depletion assessment should be repeated periodically, and rate of fluid therapy modified based on signs of volume depletion.
parenteral or rectal antiemetics
Treatment recommended for SOME patients in selected patient group
In patients with intractable vomiting, parenteral (or rectal) antiemetic therapy (i.e., phenothiazines, dopamine antagonists, or 5-HT3 antagonists) may be necessary. Evidence suggests that ondansetron may be more effective at controlling severe vomiting than metoclopramide.[25]Kashifard M, Basirat Z, Kashifard M, et al. Ondansetrone or metoclopromide? Which is more effective in severe nausea and vomiting of pregnancy? A randomized trial double-blind study. Clin Exp Obstet Gynecol. 2013;40(1):127-30. http://www.ncbi.nlm.nih.gov/pubmed/23724526?tool=bestpractice.com [26]Slattery J, Quinten C, Candore G, et al. Ondansetron use in nausea and vomiting during pregnancy: a descriptive analysis of prescription patterns and patient characteristics in UK general practice. Br J Clin Pharmacol. 2022 Oct;88(10):4526-39. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9545331 http://www.ncbi.nlm.nih.gov/pubmed/35483963?tool=bestpractice.com
However, in 2019 studies showed an increased risk of cleft palate following the use of ondansetron during the first trimester of pregnancy.[27]Huybrechts KF, Hernández-Díaz S, Straub L, et al. Association of maternal first-trimester ondansetron use with cardiac malformations and oral clefts in offspring. JAMA. 2018 Dec 18;320(23):2429-37. https://jamanetwork.com/journals/jama/fullarticle/2718793 http://www.ncbi.nlm.nih.gov/pubmed/30561479?tool=bestpractice.com The European Medicines Agency's pharmacovigilance risk assessment committee has recommended limiting the use of ondansetron during the first trimester of pregnancy.[28]European Medicines Agency. PRAC recommendations on signals: adopted at the 8-11 July 2019 PRAC meeting. Aug 2019 [internet publication]. https://www.ema.europa.eu/en/documents/prac-recommendation/prac-recommendations-signals-adopted-8-11-july-2019-prac-meeting_en.pdf The UK Teratology Information Service and the European Network of Teratology Information Services suggest ondansetron should still be considered an option for patients with severe vomiting in pregnancy in whom first-line treatments have failed.[29]UK Teratology Information Service. Ondansetron: official response statement to PRAC recommendations. Sep 2019 [internet publication]. https://www.medicinesresources.nhs.uk/en/Medicines-Awareness/Safety-Alerts/Safety-alerts/Ondansetron-in-pregnancy--updated-UK-Teratology-Information-Service-UKTIS-healthcare-professional-monograph-and-patient-information-leaflet The UK Medicines and Healthcare products Regulatory Agency also issued a drug safety update for ondansetron that provides similar advice.[30]Medicines and Healthcare products Regulatory Agency. Drug safety update. Ondansetron: small increased risk of oral clefts following use in the first 12 weeks of pregnancy. Jan 2020 [internet publication]. https://www.gov.uk/drug-safety-update/ondansetron-small-increased-risk-of-oral-clefts-following-use-in-the-first-12-weeks-of-pregnancy
Ondansetron should therefore be reserved as a second-line agent for the treatment of NVP.[31]Royal College of Obstetricians and Gynaecologists. Green-top guideline no. 69: the management of nausea and vomiting in pregnancy and hyperemesis gravidarum. Feb 2024 [internet publication]. https://obgyn.onlinelibrary.wiley.com/doi/10.1111/1471-0528.17739 Patients must be adequately counseled about the benefits of ondansetron, as well as the small increase in the risk of cleft palate that may exist.
Metoclopramide should be used for up to 5 days only in order to minimize the risk of neurologic and other adverse effects.[38]European Medicines Agency. European Medicines Agency recommends changes to the use of metoclopramide. Jul 2013 [internet publication]. https://www.ema.europa.eu/en/news/european-medicines-agency-recommends-changes-use-metoclopramide
Primary options
metoclopramide: 5-10 mg intravenously/intramuscularly every 8 hours when required for a maximum of 5 days, maximum 30 mg/day
More metoclopramideConsidered safe in pregnancy.
Secondary options
ondansetron: 4-8 mg intravenously every 12 hours when required
More ondansetronReserved as a second-line agent due to the small increase in the risk of cleft palate that may exist.
OR
chlorpromazine: 12.5 to 25 mg intramuscularly every 4-6 hours when required
More chlorpromazineUse only if maternal benefits outweigh risks to fetus.
OR
prochlorperazine maleate: 5-10 mg intramuscularly/intravenously every 6-8 hours when required, maximum 40 mg/day
More prochlorperazine maleateUse only if maternal benefits outweigh risks to fetus.
OR
prochlorperazine rectal: 25 mg twice daily when required
More prochlorperazine rectalUse only if maternal benefits outweigh risks to fetus.
OR
promethazine: 12.5 to 25 mg intramuscularly/intravenously every 4-6 hours when required
More promethazineUse only if maternal benefits outweigh risks to fetus.
OR
droperidol: consult specialist for guidance on dose
More droperidolUse only if maternal benefits outweigh risks to fetus.
proton-pump inhibitor alone or in combination with antiemetic
Treatment recommended for SOME patients in selected patient group
Proton-pump inhibitors (PPIs) may be used as an alternative treatment option to parenteral or rectal antiemetics, or in combination with them.[32]Einarson A, Maltepe C, Boskovic R, et al. Treatment of nausea and vomiting in pregnancy: an updated algorithm. Can Fam Physician. 2007 Dec;53(12):2109-11. https://www.cfp.ca/content/53/12/2109.full http://www.ncbi.nlm.nih.gov/pubmed/18077743?tool=bestpractice.com Data have demonstrated that PPIs are safe in pregnancy and are not associated with a significant increase in birth defects.[33]Pasternak B, Hviid A. Use of proton-pump inhibitors in early pregnancy and the risk of birth defects. N Engl J Med. 2010 Nov 25;363(22):2114-23. http://www.ncbi.nlm.nih.gov/pubmed/21105793?tool=bestpractice.com However, analysis of data derived from observational studies suggests that PPI use during pregnancy may be associated with a modest increased risk of asthma during childhood.[34]Lai T, Wu M, Liu J, et al. Acid-suppressive drug use during pregnancy and the risk of childhood asthma: a meta-analysis. Pediatrics. 2018 Feb;141(2):e20170889. http://www.ncbi.nlm.nih.gov/pubmed/29326337?tool=bestpractice.com Of the PPIs, omeprazole has been the most studied and has well-documented safety data.
Primary options
omeprazole: 20-40 mg intravenously once daily
More omeprazoleUse only if maternal benefits outweigh risks to fetus.
corticosteroids
Treatment recommended for SOME patients in selected patient group
Corticosteroids can be considered after the first trimester (their use has been associated with cleft palate in fetuses exposed in the first trimester).[2]American College of Obstetricians and Gynecologists. Practice bulletin no. 189: nausea and vomiting of pregnancy. Jan 2018 [internet publication]. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy [35]Park-Wyllie L, Mazzotta P, Pastuszak A, et al. Birth defects after maternal exposure to corticosteroids: prospective cohort study and meta-analysis of epidemiological studies. Teratology. 2000 Dec;62(6):385-92. http://www.ncbi.nlm.nih.gov/pubmed/11091360?tool=bestpractice.com
A randomized, double-blind, controlled study has demonstrated improvement in symptoms.[36]Safari HR, Fassett MJ, Souter IC, et al. The efficacy of methylprednisolone in the treatment of hyperemesis gravidarum: a randomized, double-blind, controlled study. Am J Obstet Gynecol. 1998 Oct;179(4):921-4. http://www.ncbi.nlm.nih.gov/pubmed/9790371?tool=bestpractice.com
Primary options
methylprednisolone: 16 mg orally/intravenously every 8 hours for 3 days, then taper gradually over 2 weeks
More methylprednisoloneUse only if maternal benefits outweigh risks to fetus.
OR
prednisone: 40-75 mg orally once daily
More prednisoneUse only if maternal benefits outweigh risks to fetus.
nutritional supplementation
Treatment recommended for SOME patients in selected patient group
In extreme cases, patients may require enteral feeding or total parenteral nutrition to provide calories and replace electrolytes and nutrients. Consultation with specialists from maternal-fetal medicine and gastroenterology, and the inpatient parenteral nutrition service, is required.
Enteral feeding has been shown to be effective in one small study utilizing a nasogastric tube with infusion rates up to 100 mL/hour.[37]Hsu JJ, Clark-Glena R, Nelson DK, et al. Nasogastric enteral feeding in the management of hyperemesis gravidarum. Obstet Gynecol. 1996 Sep;88(3):343-6. http://www.ncbi.nlm.nih.gov/pubmed/8752236?tool=bestpractice.com
Helicobacter pylori eradication therapy
Treatment recommended for SOME patients in selected patient group
In severe cases, patients who test positive for Helicobacter pylori may be treated with standard eradication regimens.[7]Goldberg D, Szilagyi A, Graves L. Hyperemesis gravidarum and Helicobacter pylori infection: a systematic review. Obstet Gynecol. 2007 Sep;110(3):695-703. http://www.ncbi.nlm.nih.gov/pubmed/17766620?tool=bestpractice.com
There are many different regimens available; consult specialist for guidance on choosing the most appropriate regimen for a pregnant woman.
Choose a patient group to see our recommendations
Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer
Use of this content is subject to our disclaimer