Not every pregnant woman will experience morning sickness, although most do to some degree, and it can vary from a feeling of mild nausea or queasiness ranging up to feeling truly dreadful and unable to keep any food or liquids down. The severity of the effects seems to be greatest in women with a history of migraine or travel sickness.

It's not known exactly what causes it, but most doctors agree that the changes in hormone levels that pregnancy triggers are the most major factor. One of the effects of these hormones is to change the way your digestive system works, which can lead to higher levels of acid.

Another possible cause is that many women experience a heightened sense of taste and smell while pregnant, which can make nausea feel worse when unpleasant or strong odours are around.

Finally, tiredness and stress play a part, and most pregnant women are tired and stressed a lot of the time!

Morning sickness can occur over the full range of your pregnancy, but most women find that it more or less disappears by around 14 weeks as hormone levels in the body stabilise.

There are dozens and dozens of traditional 'cures' for the feelings of nausea, with every mother having an opinion on the subject! The fact is that every woman's body is different and so no single thing will work for everyone. However, there are some simple things to try which can help most feel better.

As previously mentioned, an empty stomach can be a cause, so snack little and often to keep hunger at bay, and keep a couple of biscuits by your bed for if you wake up during the night.

Sucking on an ice cube can help, as can fizzy drinks. Fresh ginger is reputed to calm the stomach, so making a tea from crushed root ginger or even chewing on a piece can be worth a try.

Remedies for travel sickness can also help, so it might be worth trying the magnetic wristbands you can buy, but you should never take any medication while pregnant without consulting your doctor.

Morning sickness is a natural part of pregnancy and will not harm your baby in any way, but in severe cases you may be unable to keep any food or fluids down and if this continues you could become dehydrated, which is very dangerous for your baby. If your urine starts to become very dark in colour this is a sign that your fluid levels are too low, and you should speak to your midwife or doctor.

Finally, when you're in a bout of morning sickness, don't worry too much about what you're eating - getting enough energy is more important than a balanced diet at that moment, so if chocolate makes you feel better then go for it! You can always stock up on healthier foods when the sickness has abated a little.