Nausea and Vomiting in Pregnancy: What's Normal, When to Seek Help, and Tips That Really Work
For many women, nausea and vomiting of pregnancy (NVP) is one of the earliest signs of pregnancy. Despite often being called “morning sickness,” symptoms can occur at any time of the day or night and can range from mild nausea to persistent vomiting that significantly affects everyday life.
The reassuring news is that nausea and vomiting are very common in pregnancy and, for most women, improve as pregnancy progresses. However, if symptoms are affecting your ability to eat, drink, work or manage your normal day, early treatment is important.
Dr Emma Tetstall: “Nausea and vomiting can be really tough, and just because they’re common in pregnancy doesn’t mean you have to simply put up with them. If you’re struggling to eat or drink, get through work, look after your family, or just get through the day, please talk to us. There are lots of things we can do to help, and we’ll work out what feels right for you.”
How Common is Nausea and Vomiting of Pregnancy?
Nausea and vomiting affect up to 80% of pregnant women, while vomiting occurs in approximately 50%. At the more severe end of the spectrum, hyperemesis gravidarum (HG) affects approximately 0.3–3.6% of pregnancies, depending on the definition and population studied.
Symptoms typically begin in early pregnancy, often between 4 and 7 weeks, and are usually most troublesome during the first trimester. For most women symptoms improve by around 14-16 weeks, although some experience nausea and vomiting for up to 20 weeks, and sometimes longer.
What Causes Pregnancy Sickness?
The exact cause is complex and not completely understood. Pregnancy-related hormonal changes, including human chorionic gonadotrophin (hCG), are thought to play an important role.
Women carrying twins or another multiple pregnancy may have a higher likelihood of significant symptoms, and women who experienced nausea and vomiting in a previous pregnancy are more likely to experience it again.
Importantly, pregnancy sickness isn't caused by something you've eaten or done.
5 Top Tips for Managing Nausea and Vomiting in Pregnancy
1. Eat Little and Often
An empty or over full stomach or can make nausea more difficult for some women. Try small meals or snacks regularly throughout the day rather than three large meals. Plain or carbohydrate-rich foods such as crackers, toast, rice or cereal may be easier to tolerate.
Keeping a small snack beside your bed and eating something before getting up in the morning can also be worth trying.
2. Sip Fluids Regularly
Try taking small, frequent sips rather than drinking a large amount at once. Cold water, ice chips, icy poles or electrolyte drinks may be easier to tolerate. Drinks with flavour - especially lemon, may also be easier to tolerate.
Don't become too focused on drinking a particular type of fluid. When you are feeling very nauseated, sometimes whatever fluid you can tolerate is the best place to start.
If you cannot keep fluids down or are passing very little or dark urine, seek medical advice as these may be signs of dehydration.
3. Consider Your Pregnancy Multivitamin
Pregnancy multivitamins, particularly those containing iron, can sometimes worsen nausea and gastrointestinal symptoms.
If your symptoms are significant, speak with your obstetrician about temporarily stopping your multivitamin, changing preparations or taking individual supplements instead.
It remains important to take folic acid during early pregnancy. Australian pregnancy guidance recommends at least 400 micrograms (0.4 mg) daily, ideally commencing at least 1 month before conception and continuing through the first 12 weeks of pregnancy. Some women require a higher dose because of individual risk factors.
It is also important to take 150 mcg iodine daily and 400 IU of Vitamin daily throughout pregnancy. These can be found individually and are normally well tolerated.
Don't stop supplements that have been specifically prescribed for you without discussing this with your doctor.
4. Try Ginger or Vitamin B6
Ginger may help some women with mild-to-moderate pregnancy nausea and is included as a non-pharmacological option in pregnancy nausea guidance.
Vitamin B6 (pyridoxine) may also help reduce nausea and is commonly incorporated into first-line treatment strategies.
Talk to your doctor or pharmacist about appropriate preparations and doses during pregnancy.
5. Ask for Help Early
You don't need to wait until you are severely unwell before asking for help.
There are several anti-nausea medications that can be used during pregnancy. Treatment can be tailored according to your symptoms, gestation, medical history and response to previous treatments. Treating other associated symptoms such as constipation and heartburn or reflux can also be beneficial.
Early treatment can help maintain hydration and nutrition and potentially prevent symptoms becoming severe enough to require intravenous fluids or hospital treatment.
Dr Emma Tetstall: ““Lots of women worry about taking medication, especially early in pregnancy. I think it’s important to talk through the options, what we know about their safety, and how much the nausea is affecting you, so we can work out what’s right for you.”
When Does Pregnancy Sickness Become Hyperemesis Gravidarum?
Hyperemesis gravidarum (HG) is at the severe end of the spectrum of nausea and vomiting in pregnancy. It is more than simply “bad morning sickness”.
Traditionally, HG has been associated with persistent vomiting, dehydration, electrolyte abnormalities and weight loss of more than 5% of pre-pregnancy body weight.
However, the more recent definition recognise that a woman does not need to become severely dehydrated or lose a particular amount of weight before her symptoms are considered significant.
The international Windsor definition for hyperemesis gravidarum requires all of the following criteria:
severe nausea and/or vomiting
starting in early pregnancy < 16 weeks gestation
an inability to eat and/or drink normally
and symptoms that strongly limit daily activities.
This is important because treatment should not be delayed until you become extremely unwell.
Seek medical review if you cannot maintain your usual food or fluid intake, are losing weight, have very dark or reduced urine, feel faint or dizzy, or are finding it difficult to manage normal daily activities.
Pregnancy Sickness: Myth or Fact?
Myth: Morning sickness only happens in the morning
False. Despite the name, nausea and vomiting can occur at any time of the day or night.
Myth: Really bad morning sickness means you're having twins
Not necessarily. Multiple pregnancy is associated with an increased likelihood of nausea and vomiting, but significant pregnancy sickness also occurs in women carrying one baby.
Your symptoms cannot tell you whether you are carrying twins.
Myth: Lots of nausea means you're having a girl
Not quite. Research has identified an association between hyperemesis gravidarum and carrying a female fetus, but the relationship isn't strong enough to predict your baby's sex.
So unfortunately, how sick you feel isn't a reliable substitute for an ultrasound or genetic testing!
Myth: You shouldn't take anti-nausea medication during pregnancy
False. There are a number of medications used to manage nausea and vomiting during pregnancy. The appropriate medication depends on your individual circumstances, which is why treatment is best discussed with your G.P. or obstetrician
When should I contact my obstetrician or care giver?
Contact your obstetrician or maternity care provider if nausea or vomiting is affecting your ability to eat, drink, work, sleep or carry out your normal activities.
Seek prompt medical assessment if you:
cannot keep fluids down;
are passing very little urine or have very dark urine;
feel dizzy, faint or significantly weak;
are losing weight;
have severe abdominal pain or fever;
vomit blood; or
feel that your symptoms are becoming unmanageable.
You Don't Have to “Push Through”
Nausea and vomiting may be a common part of pregnancy, but common doesn't mean you have to simply endure it.
Every woman's experience is different. Some women manage their symptoms with dietary and lifestyle changes, while others need medication, intravenous fluids or more intensive treatment.
At our practice, we take the time to understand how pregnancy sickness is affecting you, rather than focusing only on how many times you are vomiting. Treatment can then be individualised to help you remain hydrated, nourished and as comfortable as possible throughout your pregnancy.
If nausea or vomiting is affecting your quality of life, don't wait until your next routine appointment. Contact our rooms, or your caregiver, so we can help you access appropriate treatment and support.
Where can I get more information?
Nausea and Vomiting of Pregnancy (NVP) and Hyperemesis Gravidarum (HG) - Royal Hospital for Women/MotherSafe Factsheet
References
1. Society of Obstetric Medicine of Australia and New Zealand (SOMANZ). Guideline for the Management of Nausea and Vomiting in Pregnancy and Hyperemesis Gravidarum. Society of Obstetric Medicine of Australia and New Zealand.
2. The Royal Women's Hospital. Nausea and Vomiting in Pregnancy. Melbourne: The Royal Women's Hospital.
3. Royal College of Obstetricians and Gynaecologists (RCOG). The Management of Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum. Green-top Guideline No. 69. London: RCOG.
4. Jansen LAW, Koot MH, Van't Hooft J, et al. The Windsor definition for hyperemesis gravidarum: a multistakeholder international consensus definition. European Journal of Obstetrics & Gynecology and Reproductive Biology. 2021;266:15–22.
5. Australian Government Department of Health. Clinical Practice Guidelines: Pregnancy Care – Nutritional Supplements. Australian Government.
6. Veenendaal MVE, van Abeelen AFM, Painter RC, van der Post JAM, Roseboom TJ. Consequences of hyperemesis gravidarum for offspring: a systematic review and meta-analysis. BJOG. 2011;118(11):1302–1313.
7. Hinkle SN, Mumford SL, Grantz KL, et al. Association of nausea and vomiting during pregnancy with pregnancy loss: a secondary analysis of a randomized clinical trial. JAMA Internal Medicine. 2016;176(11):1621–1627.
Frequently Asked Questions
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Hyperemesis gravidarum is the severe end of pregnancy nausea and vomiting. Newer definitions focus particularly on severe nausea and/or vomiting, inability to eat or drink normally, and significant restriction of everyday activities.
You don't need to wait until you've lost 5% of your body weight or become severely dehydrated before seeking help.
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Symptoms usually begin during early pregnancy, commonly around 4–7 weeks, and are often most noticeable during the first trimester.
For many women they improve by around 14- 16 weeks, stopping prior to 20 weeks, although some women continue to experience symptoms later in pregnancy.
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Yes. Several medications can be used to manage nausea and vomiting during pregnancy.
Depending on your symptoms and individual circumstances, your doctor may recommend pyridoxine (vitamin B6), doxylamine or other anti-nausea medications. Sometimes a combination of treatments is required, particularly when symptoms are more severe.
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If your multivitamin is making your nausea worse, speak with your obstetrician or care giver. Iron-containing supplements can worsen gastrointestinal symptoms for some women, and temporarily changing or stopping a multivitamin may be appropriate.
However, you still need folic acid, iodine and vitamin D particularly during early pregnancy.
Don't stop a supplement that has been specifically prescribed for you without medical advice.
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Nausea and vomiting are extremely common in normal pregnancies. Some research has found an association between nausea and vomiting and a lower risk of pregnancy loss, but symptoms vary enormously between women.
Importantly, not experiencing morning sickness does not mean there is anything wrong with your pregnancy.
