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Your home for information about Nausea and Vomiting of Pregnancy

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Nausea and Vomiting of Pregnancy (NVP) is the most common medical illness of pregnancy, affecting up to 80% of all pregnant women.1-3 It can range from mild to severe in nature with NVP being one of the most common indications for hospital admission during the first trimester of pregnancy.4,5

Whilst many women with NVP can cope with conservative management, approximately a third of women with NVP are prescribed an off license medication for this condition.6

NVP can have serious adverse effects on quality of life for pregnant women and their families1-3 with 87% of NVP sufferers experiencing nausea more than 5 times or constantly throughout the day.Severe NVP is associated with severe dehydration, malnutrition and electrolyte imbalances.3,4,8  and the most severe form of NVP is known as hyperemesis gravidarum (HG) and affects up to 3.6% of pregnant women.3,9,10 In women who have had severe NVP or HG in a prior pregnancy, failing to treat the early stages of NVP may increase the risk of subsequent hospitalisation.3,11-13

This website provides an overview of NVP, including information about how to assess its severity and how to support women with the condition. It also includes details on conservative treatment, along with an overview of Xonvea (doxylamine succinate 10mg/pyridoxine hydrochloride 10mg), which is now licensed in the UK for the treatment of NVP in women where conservative management has failed.


The only licensed medicine in the UK for the treatment of NVP where conservative management has failed

  • Indicated for women who do not respond to conservative management.
  • A large amount of data on pregnant women indicates no fetal toxicity.14
  • Xonvea’s combination of doxylamine and pyridoxine is recommended as a 1st line pharmacotherapy in each of the clinical guidelines to USA, Canada, Spain and Ireland and has been prescribed to over 33 million women for more than 40 years.10,15-18
  • Xonvea significantly improves the symptoms and quality of life for women with NVP versus placebo.19
Find out more
Best Practice Open Theatre.

Nausea and Vomiting of Pregnancy explained

Professor Catherine Nelson-Piercy is a consultant obstetric physician at Imperial College Healthcare NHS Trust and Guy’s and St. Thomas’ Hospitals Trust.

Watch Professor Catherine Nelson-Piercy present at a symposium for NVP by clicking on the find out more button.

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Pregnant woman suffering with nausea in morning.

Impact of Nausea and Vomiting of Pregnancy

NVP can have a significant physical, psychological and social impact on pregnant women,2,3,7,8,20-25  and is one of the most common indications for admission to hospital during pregnancy.3-5

Find out more about the impact of NVP
Doctor with laptop and pregnant woman in doctor's office smiling.

Assessing and managing symptoms of Nausea and Vomiting of Pregnancy

Understanding more about NVP as a condition may support you in the clinical management of your patient.

Find out more


  1. Einarson A, Maltepe C, Boskovic R, Koren G. Treatment of nausea and vomiting in pregnancy. An updated algorithm. Can Fam Phys 2007; 53: 2109-2111.
  2. Association of Professors of Gynecology and Obstetrics. Nausea and Vomiting of Pregnancy. Continuing series on Women’s Health Education. 2011; Jespersen & Associates, LLC, Boston, Massachusetts.
  3. Royal College of Obstetricians and Gynaecologists. The management of nausea and vomiting of pregnancy and hyperemesis gravidarum (Green-top Guideline No. 69). 22 June 2016. Royal College of Obstetricians and Gynaecologists: London. https://www.rcog.org.uk/en/guidelines-researchservices/guidelines/gtg69/.
  4. Mitchell-Jones N, et al. Ambulatory versus inpatient management of severe nausea and vomiting of pregnancy: a randomised control trial with patient preference arm. BMJ Open 2017;7:e017566. doi:10.1136/bmjopen-2017-017566.
  5. Gazmararian JA, Petersen R, Jamieson DJ, et al. Hospitalizations During Pregnancy Among Managed Care Enrollees. Obstet Gynecol 2002;100:94 –100.
  6. Gadsby R et al. Nausea and vomiting of pregnancy and resource implications: The NVP Impact Study. Br J Gen Pract. 2018. Manuscript accepted for publication.
  7. Mazzotta P. Attitudes, Management and Consequences of Nausea and Vomiting of Pregnancy in the United States and Canada.Internat J Gynecol Obstet 2000; 70: 359-365.
  8. Stokke G, Gjelsvik BL, Flaatten KT, Birkeland E, Flaatten H, Trovik J. Hyperemesis gravidarum, nutritional treatment by nasogastric tube feeding: a 10-year retrospective cohort study. Acta Obstet Gynecol Scand. 2015;94:359–67.
  9. Madjunkova S et al. Pediatr Drugs 2014; 16: 199-211.
  10. American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 189, January 2018. Nausea and vomiting of pregnancy. Obstet. Gynecol. 2018;131:e15-e30.
  11. Neutel CI. Variation in rates of hospitalisation for excessive vomiting in pregnancy by Bendectin/ Diclectin use in Canada. Nausea and Vomiting of Pregnancy: State of the Art 2000. 54-59.
  12. Maltepe C et al. The management of nausea and vomiting of pregnancy and hyperemesis gravidarum – a 2013 update. J Popul Ther Clin Pharmacol. 2013;20:e184-e192.
  13. Koren G et al. Pre-emptive therapy for severe nausea and vomiting of pregnancy and hyperemesis gravidarum. J Obstet Gynaecol. 2004 Aug;24(5):530-533.
  14. Xonvea 10 mg/10 mg gastro-resistant tablets Summary of Product Characteristics.
  15. The Society of Obstetricians and Gynaecologists of Canada. J Obstet Gynaecol Can. 2016;38(12):1127-1137.
  16. Institute of Obstetricians & Gynaecologists Clinical Practice Guidelines, Royal College of Physicians of Ireland. Hyperemesis and nausea/vomiting in pregnancy. Guideline 12; v1 (Nov 2015).
  17. Spanish Society of Gynecology & Obstetrics (SEGO) Consensus Document Hyperemesis Gravidarum; 2008:61-100.
  18. Ornstein, M., Einarson, A., Koren, G. Bendectin/Diclectin for morning sickness: A Canadian follow-up of an American tragedy. Reproductive Toxicology. 1995; 9(1): 1-6.
  19. Koren G et al. American Journal of Obstetrics & Gynaecology. 2010;203:571.e1–571.e7.
  20. Lacroix R, Eason E, Melzack R. Nausea and vomiting during pregnancy: a prospective study of its frequency, intensity, and patterns of change. Am J Obstet Gynecol 2000; 182(4): 931-937.
  21. O’Brien B et al. Nausea and vomiting during pregnancy: effects on the quality of women’s lives. Birth 1992; 19:138-143.
  22. Tan, P (2010). Anxiety and depression in hyperemesis gravidarum: Prevalence, risk factors and correlation with clinical severity. European Journal of Obstetrics & Gynecology and Reproductive Biology, 149, 153-158.
  23. Kramer, J. et al. Nausea and Vomiting of Pregnancy: Prevalence, Severity and Relation to Psychosocial Health. The American Journal of Maternal/Child Nursing. 2013; 38(1): 21-27.
  24. Gadsby R, Barnie-Adshead T. Severe nausea and vomiting of pregnancy: should it be treated with appropriate pharmacotherapy. The Obstetrician & Gynaecologist 2011;13:107–111.
  25. Piwko C, Koren G, Babashov V, Vicente C, Einarson TR. Economic burden of nausea and vomiting of pregnancy in the USA. J Popul Ther Clin Pharmacol. 2013;20(2):e149-e160.