Nausea and Vomiting in Pregnancy (Morning Sickness)


Published: 09 November 2022

Between half and two-thirds of people experience feelings of malaise - specifically nausea and vomiting - during pregnancy (Better Health Channel 2022).

The colloquial term ‘morning sickness’ is considered to be an inaccurate name for these symptoms, as a person may feel ill at any point during the day (or night) and symptoms are not exclusive to the hours of the morning. Therefore, the preferred term is nausea and vomiting in pregnancy (NVP) (Tan et al. 2016).

NVP typically affects birthing parents during the first trimester. However, some people will experience these symptoms all the way up until delivery (Smith et al. 2021; Healthdirect 2020).

Across healthcare, NVP is still not well understood in terms of why it occurs and how it manifests (Taylor 2019).

Woman vomting into toilet
Feeling ill can occur at any point during the day (or night) and is not exclusive to the hours of the morning.

What is the consequence of this?

There are many reported cases of doctors, midwives, pharmacists and other health professionals dismissing claims of severe morning sickness, contributing to the stigmatisation of NVP as something that those who are pregnant exaggerate or make up (Taylor 2019).

This contradicts research into the prevalence of NVP, which is estimated to affect up to 80% of people during pregnancy. NVP ranges from mild nausea and vomiting to pathologic hyperemesis gravidarum (Healthdirect 2020).

Severe Nausea and Vomiting in Pregnancy

Severe NVP, known as hyperemesis gravidarum (HG), affects one in 1,000 people during pregnancy.

HG is defined as nausea and vomiting so intense that it results in electrolyte abnormalities, dehydration, and weight loss of around 5% of (pre-pregnancy) weight.

Treatment for HG usually requires admission to hospital (Better Health Channel 2022).

Causes of Nausea and Vomiting in Pregnancy and Hyperemesis Gravidarum

While the exact causes of NVP and HG occur are unknown, nausea and vomiting during pregnancy are commonly accepted to be associated with pregnancy-related hormonal changes (Pregnancy, Birth & Baby 2021).

Risk Factors for Nausea and Vomiting in Pregnancy

  • Being pregnant for the first time
  • Obesity
  • Stress
  • History of NVP in a previous pregnancy
  • Multiple pregnancy
  • History of nausea and vomiting when taking oestrogen (e.g. contraceptive pill)
  • History of migraines
  • History of motion sickness
  • Family history of NVP
  • History of gastrointestinal issues such as reflux or ulcers
  • Molar pregnancy.

(Smith et al. 2021; NHS 2021)

Woman awake in bed next to her partner
The exact reasons why NVP and HG occur are unknown.

Symptoms of Nausea and Vomiting in Pregnancy

It’s common for symptoms of NVP to appear in the first four to nine weeks of pregnancy (DoHAC 2019).

Primary symptoms of NVP include:

  • Nausea
  • Vomiting
  • Loss of appetite
  • Psychological complications (e.g. depression or anxiety).

(Better Health Channel 2022)

NVP and Healthy Pregnancy

A person who is pregnant may be concerned that frequent vomiting could pose a health risk to their baby - this is an unfounded fear. In fact, the opposite appears to be true: studies suggest that mild to moderate morning sickness is linked to a reduced risk of miscarriage (Better Health Channel 2022).

This aside, prolonged periods of vomiting that cause dehydration and weight loss could deprive the baby of adequate nutrition, increasing the risk of the baby being born underweight (Better Health Channel 2022).

HG should be treated without delay to avoid serious health complications for both the birthing parent and the child (Better Health Channel 2022).

Managing Morning Sickness

Dietary Modifications

  • Eat smaller amounts of food more often
  • Preference bland foods that are low in fat
  • Avoid spicy foods
  • Eat foods high in protein
  • Don’t skip meals
  • Avoid cooking or being in the kitchen when food is being prepared if this triggers nausea
  • Eat a few dry crackers or biscuits prior to getting out of bed
  • Ginger (in any form) is widely suggested to aid NVP symptoms
  • Aim to drink eight glasses of water per day
  • Carbonated drinks or ginger/peppermint tea may relieve symptoms.

(Pregnancy, Birth & Baby 2021; Tan et al. 2016)

Crackers in a bowl
Eat smaller amounts of food more often.

Seek Support

Emotional support offered by a medical professional is advisable in the case of severe NVP or HG. This is particularly relevant for people who are experiencing severe symptoms as well as additional sources of stress such as marital or family conflict. Therapy may include supportive psychotherapy, behavioural therapy or hypnotherapy (Lee & Saha 2011).

The main goal of this therapy is not to treat NVP symptoms, but to encourage the patient to express stress and emotions and improve their quality of life (Lee & Saha 2011).


There is inconclusive evidence regarding the success of treating severe NVP and HG using acupressure and/or acupuncture, but research has shown that some people find it useful for managing nausea and vomiting. Despite insufficient research, many experts see it as a valid intervention given its reported success in certain trials and the fact that no adverse side effects are known (Lee & Saha 201; BBC News 2016).


Nausea and vomiting in pregnancy is a common condition and may even be an indicator of a healthy pregnancy. It is, however, debilitating for some people and should not be underestimated in its severity.

For some, NVP causes a significant reduction in quality of life. While it can often be managed through diet and lifestyle changes, further intervention may be necessary in severe cases. Hyperemesis gravidarum should be treated vigorously to prevent birthing parent and fetal mortality.


Test Your Knowledge

Question 1 of 3

True or false: NVP typically only occurs in the morning.


educator profile image
Ausmed View profile
Ausmed’s editorial team is committed to providing high-quality, well-researched and reputable education to our users, free of any commercial bias or conflict of interest. All education produced by Ausmed is developed in consultation with healthcare professionals and undergoes a rigorous review process to ensure the relevancy of all healthcare information and updates to changes in practice. If you have identified an issue with the education offered by Ausmed or wish to submit feedback to Ausmed's editorial team, please email with your concerns.