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Severe nausea and vomiting or gestational hyperemesis

Maternal pregnancy complications

What is gestational hyperemesis?

Gestational hyperemesis is the scientific term for severe and persistent nausea and vomiting in pregnant women. It is defined by intense nausea that can cause weight loss, dehydration, and electrolyte imbalance (sodium, potassium, chlorine, magnesium, calcium, etc.). Hospitalization is usually necessary with this condition, which occurs in about 1 in every 100 pregnancies.

Several predisposing or aggravating factors can explain the occurrence of gestational hyperemesis:

  • Changes in hormones during pregnancy (gonadotropin chorionic hormone (hCG), estrogen, progesterone)
  • First pregnancy
  • Pregnancy at a young age
  • Excess weight
  • Pregnancy with twins or triplets
  • Nausea and vomiting in a previous pregnancy (NVP)

The presence of iron in prenatal multivitamins as well as certain medical conditions (hyperthyroidism, migraines, motion sickness, stress and anxiety, etc.) can also be predisposing or aggravating factors.

What are the consequences of pregnancy hyperemesis?

  • Pregnancy hyperemesis is not associated with any adverse effects on the baby, and there is no increased risk of birth defects.
  • It can, however, be a source of psychological distress that should not be ignored.
    • Affected sleep causing fatigue, irritability, and symptoms of anxiety and depression.
    • Disruption of day to day functioning, at work and at home.

How do you prevent pregnancy hyperemesis?

Lifestyle adjustments can prevent or help control NVP. Here are some tips that might help:


  • Taking a prenatal multivitamin before you get pregnant can reduce nausea and prevent it from becoming gestational hyperemesis.
  • Some multivitamins irritate the stomach because of their iron content. It is possible to replace them with folic acid alone until NVP is better controlled. Folic acid should be continued until at least the 12th week of pregnancy.
  • Stay hydrated and do not wait until you are hungry to eat.
  • Fasting because of nausea can actually make you feel worse. It is better to eat small meals or frequent snacks. Choose foods that appeal to you and that ideally contain protein (such as nuts) and sip water between snacks so as not to overstretch your stomach all at once.
  • Avoid odours that may cause nausea.
  • Stand up slowly to avoid a drop in blood pressure, dizziness, and further retching.
  • Take time to rest and avoid going to bed immediately after a meal.
  • Do not hesitate to ask for support from those around you or from a health professional. There are telephone services dedicated to advising and supporting pregnant women.


Safe and effective NVG medications can be used when lifestyle changes are not enough.

Do not hesitate to consult a health professional who can suggest a treatment, dosage, and formulation (tablet, liquid, or suppository) appropriate to your situation.

What are the treatments used to relieve pregnancy hyperemesis?

Hospitalization is often preferable in cases of gestational hyperemesis because hydration, vitamins, and medications can be administered intravenously. A complete assessment can also be carried out to help identify the causes of the symptoms.

Hospitalization usually lasts for 2 to 3 days, which is enough time to rehydrate the patient, control her nausea and vomiting, and gradually reintroduce food and any oral medication.

The drugs used to control gestational hyperemesis are mostly the same as those for NVG. For example, metoclopramide, antihistamines, and vitamin B6 are often used because they are available in injectable form (administered at the beginning of hospitalization) and in tablet or liquid forms that can be gradually administered orally when symptoms are under control.

Diclectin® – a combination of doxylamine and vitamin B6 – is a delayed-release tablet. For example, a dose administered in the evening would help prevent nausea the following day. Because of this, regular intake is recommended to achieve stable relief from NVG. Up to 8 tablets are recommended daily for severe NVP. The side effects are the same as those of antihistamines.

Vitamin B6 alone is an interesting option for women who experience a lot of drowsiness with antihistamines and Diclectin®. It is one of the treatments against nausea that causes the least side effects.

Other medications such as metoclopramide (e.g. Maxeran®, Metonia®), prochlorperazine (e.g. Stemetil®), and promethazine (e.g. Phenergan®) can also be safely used during pregnancy. They are often combined with an antihistamine to optimize the control of NVP, but also to prevent a rare adverse effect (involuntary contraction of the muscles of the legs or jaw). Ondansetron (e.g. Zofran®) and corticosteroids (often referred to as cortisone) may be prescribed in difficult NVG situations.

Heartburn and regurgitation are common during gestational hyperemesis. Ranitidine (e.g. Zantac®) or omeprazole (e.g. Losec®) can be used safely to control hyperemesis during pregnancy. 

When should I see a health professional?

Do not hesitate to seek consultation in the following situations:

  • NVP occurs after the 10th week of pregnancy
  • You vomit several times a day, you lose weight, and you show signs of dehydration (dry mouth, dark urine)
  • Your vomiting is accompanied by fever or abdominal pain
  • Your vomit contains blood
  • You have shooting pains in the stomach that are not relieved by taking medication
  • You cannot control your nausea or vomiting adequately and it interferes with your daily activities or you experience adverse effects after taking a medication.

See also the video on nausea and vomiting.

Page by

Marie-Sophie Brochet

About this page
Updated on 1/25/2021
Created on 12/19/2017
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