Pregnancy - morning sickness

Around half to two thirds of all pregnant women will experience morning sickness to some degree, particularly in the first trimester. The symptoms include nausea and vomiting. For most women, morning sickness begins around the fourth week of pregnancy and resolves by the 12th week. However, one in five women endure morning sickness into their second semester, and an unfortunate few experience nausea and vomiting for the entire duration of their pregnancy.

Morning sickness is typically at its worst early in the day, hence its name, but it can strike at any point during the day or night. Despite research, the actual cause remains a mystery, but theories include hormonal changes and fluctuations in blood pressure. In most cases, morning sickness doesn’t harm the woman or the unborn child. However, severe morning sickness that includes weight loss and dehydration needs prompt medical attention.

Symptoms of morning sickness

Symptoms of morning sickness can include:

• Nausea
• Loss of appetite
• Vomiting
• Psychological effects, such as depression and anxiety.

The myth of hysteria and morning sickness

Unrelenting morning sickness can have a profound affect on a woman’s quality of life, preventing her from working, socialising and looking after her other children. Pregnant women enduring morning sickness report higher levels of psychological stress, including anxiety and depression. This prompted the fallacy that morning sickness is purely psychosomatic, which means that the woman’s fears and anxieties trigger her physical discomfort. However, there is no research to substantiate these claims.

Possible causes of morning sickness

The cause of morning sickness remains a mystery, but it is thought a combination of physical and metabolic factors play a significant role, including:

• High levels of hormones, including oestrogen
• Fluctuations in blood pressure, particularly lowered blood pressure
• Altered metabolism of carbohydrates
• The interplay of enormous physical and chemical changes that pregnancy triggers.

Morning sickness and the baby

Some women are concerned that the action of vomiting may threaten their unborn baby. Vomiting and retching may strain the abdominal muscles and cause localised aching and soreness, but the physical mechanics of vomiting won’t harm the baby. The fetus is perfectly cushioned inside its sac of amniotic fluid. In fact, numerous studies have discovered that moderate morning sickness is associated with a reduced risk of miscarriage. However, prolonged vomiting (such that it eventually leads to dehydration and weight loss) can deprive the child of proper nutrition and increase the risk of the baby being underweight at birth.

Hyperemesis gravidarum

Severe morning sickness is known as hyperemesis gravidarum (HG), and can affect around one in 1,000 pregnant women. The symptoms of HG include repeated vomiting, weight loss and dehydration. Treatment usually involves hospitalisation, and the administering of intravenous liquids and nutrition. The possible complications of untreated hyperemesis gravidarum include:

• Electrolyte imbalances
• Extreme depression and anxiety
• Malnourishment of the fetus
• Excessive strain on vital organs, including the liver, heart, kidneys and brain.

Managing morning sickness

Suggestions for coping with morning sickness include:

• Don’t take drugs of any kind, unless your doctor knows you are pregnant and has prescribed specific medications.
• Eat a few dry crackers before getting out of bed in the morning.
• Don’t try to eat anything that you suspect will make you nauseous.
• Eat small meals regularly, since an empty stomach tends to trigger nausea.
• Limit or eliminate fatty and spicy foods.
• Choose high carbohydrate and high protein foods.
• Avoid cooking or preparing foods whenever possible.
• Drink plenty of fluids, preferably water.
• Many studies have shown that ginger can ease the symptoms.
• Vitamin B6 supplements can be useful, but doses above 200mg per day can actually be harmful.
• Wear loose clothes that don’t constrict the abdomen.

See your doctor

Always seek medical advice if your morning sickness is severe, or if you feel depressed or anxious. Treatment options can include drugs that won’t harm the developing baby.

Where to get help

• Your doctor
• Maternal and child health nurse.

Things to remember

• Around half to two thirds of all pregnant women will experience morning sickness.
• Possible causes include high levels of hormones, blood pressure fluctuations and changes in carbohydrate metabolism.
• Severe morning sickness, called hyperemesis gravidarum, may require hospitalisation.

You might also be interested in:

• Folate for women.
  
• Pregnancy - birth choices.
  
• Pregnancy - week by week.
  
• Pregnancy and diet.
  

Want to know more?

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This page has been produced in consultation with and approved by:

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North East Valley Division of General Practice

Last reviewed: October 2011

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<a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Morning_sickness?open">Pregnancy - morning sickness - Better Health Channel</a><br/>
Most pregnant women will experience morning sickness, usually in their first trimester. Possible causes include high levels of hormones, blood pressure fluctuations and changes in carbohydrate metabolism. Severe morning sickness is known as hyperemesis gravidarum (HG). It can cause weight loss and dehydration and may require hospitalisation.

Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your qualified health professional. Content has been prepared for Victorian residence and wider Australian audiences, and was accurate at the time of publication. Readers should note that over time currency and completeness of the information may change. All users are urged to always seek advice from a qualified health care professional for diagnosis and answers to their medical questions.

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