Many women have nausea or vomiting during early pregnancy. Despite being called morning sickness, some women find the feeling of nausea or sickness can occur at any time throughout the day.
In a few cases, symptoms last the whole day. In most cases morning sickness is mild and needs no treatment. It is a normal part of early pregnancy.
Very rarely vomiting is so severe (hyperemesis gravidarum) that it leads to dehydration (when you are low in body fluid) and serious weight loss, and needs to be treated in hospital.
Most women find that the nausea or sickness is worst at about 9-10 weeks of pregnancy and is over by the 14th week.
A week-by-week guide to your pregnancy Symptoms
Most symptoms start roughly 6 weeks after your last period and stop by the 14th week of pregnancy. A few women find that it continues beyond that time and occasionally it lasts for the whole pregnancy.
Morning sickness has a range of symptoms that can be mild or severe. They may include the following:
In few cases there may be severe dehydration, and serious weight loss (hyperemesis gravidarum). Nausea may come and go, and can occur at any time during the day. Morning sickness appears to be more common in women carrying twins or triplets.
The exact cause of morning sickness is unknown, but it is probably linked to hormone changes that occur naturally in pregnant women. There is a sudden rise of a hormone called human chorionic gonadotrophin (HCG) during early pregnancy, which controls the production of other pregnancy hormones. Levels of this hormone rise rapidly during the first six weeks, are greatest at approximately 10 weeks, and begin to fall at approximately 12 weeks.
Symptoms can be made worse by emotional stress, some foods, smells, fumes, smoke, or travelling. Some researchers think that pregnant women become more sensitive to smells as a natural protective measure; it may makes them more aware of things in the environment that are harmful for the unborn baby.
Morning sickness is associated with a healthy pregnancy, and is linked to a lower miscarriage rate and larger healthier babies. It is uncertain why this is the case; one hypothesis suggests that reduced food intake at the beginning of the pregnancy causes a corresponding increase in the size of the placenta, which ensures better nutrition for the baby for the rest of the pregnancy, reducing the risk of miscarriage.
No treatment is needed in most cases, as the symptoms are often mild.
If symptoms are so severe that it interferes with your everyday life, and is stopping you from gaining weight normally or causing weight loss, you should see your GP. You will probably be prescribed a medicine (an anti-emetic) to stop the vomiting.
It is worth noting that there havent yet been many studies to test the safety of anti-emetics in pregnancy, and it is generally best to avoid taking medicines during pregnancy. Medicines should only be taken when you are pregnant if the expected benefit is thought to be greater to you than the risk to the baby , so always consult your GP. However some anti-emetics have been used for a number of years and are thought to be safe and can be prescribed by your GP.
If you are vomiting a lot, the antihistamine medicine, promethazine, may help. There is no evidence that it will harm your unborn baby.
In hyperemesis gravidarum (severe vomiting), hospital treatment is often needed to stop the dehydration by giving fluids through an intravenous drip directly into a vein.
Morning sickness can occasionally last for the whole pregnancy. When it is severe, it can prevent you carrying out normal everyday life.
In its most severe form, hyperemesis gravidarum (severe vomiting) can prevent the body absorbing fluids. If this isnt treated, it can cause rapid weight loss, headaches, confusion and collapse.
Morning sickness should not harm the growing baby, and hospital treatment, if necessary, is very effective at preventing severe vomiting.
Nausea is often worse when your stomach is empty. It can help to eat a small amount of food every couple of hours. Eating can also stop your blood sugar levels from dropping. One symptom of low blood sugar is feeling sick, which adds to the effects of the hormones.
Practical tips for self-help include:
Eat small, frequent meals, high in carbohydrates and low in fat;
Keep a light snack such as a savoury biscuit or cracker by your bed and eat before getting up in the morning or if you wake in the night, to help prevent sickness in the morning;
Try to get plenty of rest as tiredness can make nausea worse;
Vitamin B6 supplements may make you feel less nauseous;
Vitamin B12 supplements may reduce the number of times you vomit. You need to start taking these supplements before you start feeling nauseous;
The tastes and smells of some foods can set off feelings of sickness. Try to avoid foods that seem to trigger your symptoms;
Air rooms well so that cooking or tobacco smells dont build up;
There is some evidence that ginger relieves sickness in some people. Try taking root ginger or ginger capsules. Ginger tea, ginger ale or ginger biscuits may also be helpful;
Have lots to drink, but avoid caffeine and alcohol , to prevent dehydration;
Complimentary therapies such as acupuncture work for some people. Travel- sickness bands, which apply pressure to the wrist, may also be worth trying.
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