Health: A Question of Health - Morning sickness occurs day or night

HOW LONG does morning sickness in pregnancy last, and are there any effective treatments?

"Morning sickness", which can occur at any time of the day or night, sometimes starts within days of conception. The worst time is usually the first three months of pregnancy, but some very unlucky women feel sick and nauseous for many months. For the vast majority of women, the feeling of sickness disappears by the time they are 16 weeks pregnant. There are dozens of dietary, herbal and medicinal "treatments" for morning sickness, but most of them have not been proven to work. Several controlled trials of acupressure (acupuncture without the needles), at the P6 point on the inner side of the wrist, have shown this to be helpful in reducing nausea and vomiting. Wrist bands (available from chemists) that are used to treat motion sickness put pressure on this point and they are certainly worth trying. Powdered ginger root (250mg, four times a day) has also been shown to work, but its safety in pregnancy has not been conclusively proved.

I HAVE been prescribed a new drug - methotrexate - for my rheumatoid arthritis. Before I started taking it I looked it up in a drug dictionary and found it's a chemotherapy drug used for cancer treatment. I am now terrified to take it. Is it the correct treatment for rheumatoid arthritis?

Methotrexate is used to treat both cancer and rheumatoid arthritis, and it is highly effective for both diseases. In chemotherapy it is prescribed for childhood leukemia and a number of other tumours. Rheumatologists use methotrexate to treat rheumatoid arthritis as it has been shown to be an effective way of suppressing the disease. It is usually not used unless other forms of treatment, such as anti-inflammatory drugs, do not control the symptoms of the disease. Methotrexate won't have an immediate effect on rheumatoid arthritis, but it may well improve symptoms over the course of several months. It can have side effects on the blood and the liver, and so it is important to have regular monitoring by blood tests. Women who are pregnant, or likely to become pregnant, must not take methotrexate.

BOTH OF my children have a bright red rash on their faces which was eventually diagnosed as Fifth Disease. I can't find any information about this, apart from the fact that it is caused by an unknown virus. What is Fifth Disease?

In the 1800s doctors identified six rashes that occurred in children. One of them - erythema infectiosum - became known as Fifth Disease because it was fifth in the list of these six rashes. The others were measles, scarlet fever, German measles, roseola infantum, and an obscure condition known as Filatow-Dukes' disease. We now know that Fifth Disease is caused by a virus known as Parvovirus B19. It is a mild illness that causes children's cheeks to go bright red. It is sometimes known as "slapped cheek disease". By the time the rash appears, children are usually not infectious any more, so keeping them isolated is futile. Pregnant women, however, can be affected by this viral infection in the first half of pregnancy, and they should consult their doctors to see if they are immune.

Please send your questions to A Question of Health, `The Independent', 1 Canada Square, Canary Wharf, London E14 5DL; fax 0171-293 2182; or e- mail health@independent.co.uk. Dr Kavalier regrets that he is unable to respond personally to questions