Nausea and Vomiting of Pregnancy (Morning Sickness)


Published: 10 November 2019

Morning sickness is the colloquial term given to feelings of malaise - specifically nausea and vomiting - experienced during pregnancy.

‘Morning sickness’ is widely considered to be an inaccurate name for the condition, as a person may feel ill at any point during the day (or night) and is not exclusive to the hours of the morning. Nausea and vomiting of pregnancy (NVP) is the preferred term.

Nausea and vomiting of pregnancy (NVP) affects birthing parents during the first trimester. However, some people will experience these symptoms all the way up until delivery (Novakovic 2017; Healthdirect 2018).

Across healthcare, there is an apparent lack of understanding of nausea and vomiting of pregnancy, in terms of why it occurs and how it manifests (Taylor 2019).

Woman vomting into toilet | Image
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 those who are pregnant exaggerate or make up (Taylor 2019).

This contradicts research into the prevalence of nausea and vomiting of pregnancy, estimated to affect 70 to 85% of people during pregnancy (Lee 2011; Healthdirect 2018). NVP ranges from mild nausea and vomiting to pathologic hyperemesis gravidarum (Lee 2011).

Interestingly, NVP is more common in Western countries and urban populations. NVP is relatively rare among African, Native American, Inuit and Asian populations (Lee 2011).

Severe Morning Sickness

Severe NVP, known as hyperemesis gravidarum (HG), affects one in 1,000 people during pregnancy. HG symptoms include weight loss, vomiting and dehydration, and usually requires the patient to be hospitalised (Better Health Channel 2013).

HG is defined as nausea and vomiting so intense that it results in electrolyte abnormalities, dehydration, and weight loss of around five per cent of (pre-pregnancy) weight (Taylor 2019).

Causes of NVP and HG

While the exact reasons why NVP and HG occur are unknown, it is commonly accepted that vomiting during pregnancy is the result of factors of metabolic and endocrine nature, particularly relating to the placenta (Lee 2011).

Risk Factors

A large North American study found that primary predictors for NVP included:

  • Being young;
  • Being pregnant for the first time;
  • Being a non-smoker;
  • Obesity;
  • Having with multiple gestations (twins, triplets, quadruplets);
  • Having a personal history of NVP;
  • Maternal genetics (having a mother who had NVP);
  • Having a personal history of motion sickness; and
  • Having a personal history of migraines.

(Lee 2011)

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

Symptoms of NVP

It is common for symptoms of morning sickness to appear around the first five to six weeks of pregnancy (Healthy WA n.d.). For many, NVP symptoms will be the first sign of pregnancy (Novakovic 2017; Stanford Children’s Health n.d.).

Primary symptoms include:

  • Nausea;
  • Vomiting;
  • Loss of appetite;
  • Psychological complications.

(Better Health Channel 2013; Healthy WA n.d.)

NVP and Healthy Pregnancy

A person who is pregnant may be concerned that frequent vomiting could pose a health risk to their child - this is an unfounded fear. The opposite appears to be true: recent studies have shown that mild to moderate morning sickness is linked with a reduced risk of miscarriage (Lafrance 2016; Lee 2011).

This aside, prolonged periods of vomiting, which causes dehydration and weight loss, could deprive a child of adequate nutrition, as a result increasing the risk of a baby being born underweight (Better Health Channel 2013).

HG should be treated without delay to avoid serious health complications for both the birthing parent and child (Better Health Channel 2013).

Managing Morning Sickness

Dietary Modifications

  • Avoid large meals;
  • Eat small amounts of food often, for example, five to six meals daily;
  • Preference bland foods that are low in fat;
  • Eat meals high in protein rather than carbohydrates;
  • Preference liquids over solids;
  • Don’t skip meals;
  • Take your time to eat;
  • Avoid cooking or being in the kitchen when food is being prepared;
  • Eating a few dry crackers or biscuits prior to getting out of bed;
  • Rest after meals if necessary;
  • Ginger (in any form) is widely suggested to aid NVP symptoms.

(Healthy WA n.d.; Lee 2011)

Crackers in a bowl | Image
Eat small amounts of food often, for example, five to six meals daily.

Seek Support

Emotional support offered by a medical professional is advisable in the case of severe NVP or HG. This is particularly relevant in the case of people who have severe symptoms as well as additional stressful factors such as marital or family conflict. Therapy may include supportive psychotherapy; behavioural therapy or hypnotherapy (Lee 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 quality of life (Lee 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 have found 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 as no adverse side effects are known (Lee 2011; BBC News 2016).


Nausea and vomiting of 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. Often it can be managed through diet and lifestyle changes but further intervention may be necessary in severe cases. Hyperemesis gravidarum should be treated vigorously to prevent birthing parent and fetal mortality.

Additional Resources


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