Hyperemesis gravidarum

What is hyperemesis gravidarum?

Morning sickness is common among pregnant women. Fortunately, for the majority it's a temporary and minor nuisance. For others, though, the term is a real misnomer. For them, sickness can occur at any time of the day and may continue throughout the course of the pregnancy.

For women with hyperemesis gravidarum, the problem is even worse - and potentially dangerous. These women would readily settle for normal morning sickness - their vomiting is so severe no food or liquid can be kept down.

Unlike most morning sickness, hyperemesis gravidarum usually persists past the first trimester (third) of pregnancy. It typically subsides by week 21 of pregnancy, but can last much longer.

Symptoms of hyperemesis gravidarum

Women with hyperemesis gravidarum often lose weight (usually over 10% of their body weight) and feel tired and dizzy. They may find they're passing water less often than usual. The danger is dehydration, as it is in any situation where fluid is lost from the body and not adequately replaced. Dehydration may cause symptoms that include headache, palpitations and confusion. There is also a risk of nutritional deficiencies.

Causes of hyperemesis gravidarum

Hyperemesis gravidarum is believed to affect up to one in 50 women in pregnancy. It tends to be more common in young mothers, women who are in their first pregnancy, and those with multiple pregnancies. It's also more common in non-smokers, although this isn't an excuse to smoke during pregnancy.

The precise cause of hyperemesis gravidarum isn't known, although there are a number of theories. These include the effect of changes in hormones, emotional changes that occur during pregnancy, nutritional deficiency, and gastrointestinal dysmotility where food pools in the digestive system rather than moving smoothly through it.

Because the cause is not yet really understood, it's not possible to prevent hyperemesis gravidarum occurring. However, it is possible, and very important, to recognise it and treat it successfully.

Treatment of hyperemesis gravidarum

In the early stages, many women with hyperemesis gravidarum will be advised to rest, eat bite-size pieces of dry toast or crackers before getting out of bed, and have frequent, small meals. Fried or spicy foods, or smells that trigger symptoms of nausea and vomiting, are best avoided.

Some women benefit from eating ginger or foods containing ginger, such as ginger biscuits and crystallised ginger, or drinking ginger herbal tea. Acupressure may help: press a finger or thumb against the inside of the wrist or wear an elastic wristband with a plastic button sewn into it. A doctor may recommend anti-nausea medication..

When symptoms are severe, admission to hospital may be needed for observation and to treat dehydration with intravenous fluids. This usually only means a few days in hospital.

Reassuringly, research has generally shown no long term harmful effects in milder cases. But in more severe cases (which are fortunately fairly rare) there is a risk of complications for both mother and baby, especially if the problem isn’t recognized and treated early. These include premature labour and pre-eclampsia.