The cause is not fully known but it is caused by changes in hormones during pregnancy. Morning sickness is normal, and there is no risk to a baby unless it is very severe.

It is also important both you and your partner understand that during pregnancy you may not enjoy certain stimuli (visual, tastes, smells, touch and sexual experiences) that you used to. These changes may place a strain on your relationship.

Some key points to note about morning sickness:

• Up to 8 in 10 pregnant women have some symptoms.
• Some may feel sick without vomiting.
• Even though it is called 'morning' sickness, you may feel sick and vomit at any time of the day or night.
• The severity of the morning sickness, and how long into the pregnancy it lasts, varies a great deal from one woman to another. It also can vary from one pregnancy to the next — you could have one pregnancy affected by morning sickness but feel fine the next time.
• It usually improves greatly by the end of the first 3 months, if not sooner, but for some women it lasts longer and sometimes until their baby is born.
• For some women it can be severe, causing them to lose weight and become dehydrated.

Managing morning sickness

In most cases no medical treatment is needed, but there are some things you can try that may make a difference.

Food: varying what and when you eat might help you to feel better. For example:

• Try eating dry biscuits and sipping a cup of weak tea or a glass of water before you get out of bed in the morning. Many women find that it helps to keep a supply of dry biscuits and a glass of water by their bed.
• Try eating smaller meals more often (rather than 3 large meals a day).
• Avoid fatty and spicey foods and coffee.
• Eat when you feel like eating rather than waiting for mealtimes.
• Try not to skip meals or go for long periods of time without eating as skipping meals can make nausea worse.
• If possible, ask someone else to prepare meals.
• Have a range of foods on hand (for example, salty, sweet, crunchy) since your taste may change during the day.

Drinks: keeping up your fluid intake is important.

• Remember to drink plenty of water — 6 to 8 glasses a day is ideal. Sucking crushed ice may also be helpful. Small drinks often may be better than large drinks.
• If you can't always manage to drink water, you may find dry ginger ale or flat lemonade better. Ginger tea, fruit juice or clear soup may also be helpful.
• If you are vomiting a lot, you will need to take extra care to make sure you are drinking enough water.
• You may like to talk with your pharmacist about drinking an oral rehydration solution. These solutions replace the important electrolytes, as well as fluid, that your body loses when you are vomiting a lot.

These other options may also help to relieve nausea:

• acupressure wristbands worn to prevent travel sickness (available from pharmacies)
• chewing ginger pieces or mints
• taking ginger tablets or vitamin B6 (talk to a pharmacist about how much to take)

If your morning sickness is worrying you, talk to your doctor or midwife. There are prescription medicines that can be used to control severe morning sickness. These medicines have not been known to cause birth defects or have other harmful effects for unborn babies.

Severe nausea and vomiting

Less than 1 in 100 pregnant women experience a condition called hyperemesis gravidarum, which causes severe nausea and vomiting. They can become very ill, lose weight and become dehydrated, and may need to be admitted to hospital to receive fluid via a drip (known as intravenous fluid) and medication.