THE GLOWING skin and glossy hair are compensation of a kind for the other, less attractive, realities of being pregnant (the morning sickness, the piles, the constipation). But now researchers think that pregnancy offers benefits beyond the merely cosmetic (and a baby). It seems that the hormonal changes associated with pregnancy could provide the key to curing medical conditions ranging from migraine to skin disorders.

Perhaps the most promising work involves the link between rheumatoid arthritis and pregnancy. Rheumatoid arthritis (RA) is a painful disease; the body attacks its own tissues, typically causing painful joint inflammation, bone erosion and cartilage loss. The condition can strike at any time, although it most commonly affects women aged 30 to 50.

Women with RA often experience a remission of symptoms while they are pregnant. Why pregnancy should offer this temporary relief has been something of a mystery. But immunologists at the Medical Research Council’s molecular biology centre in Cambridge, conducting a study funded by the Arthritis Research campaign, discovered recently that female sex hormones seem to play a vital role in controlling the disease. Dr Alex Betz, who is heading the study, has found that the expectant mother has raised levels of regulatory T immune cells, which prevent her body from rejecting the foetus. Dr Betz says: “The expansion of these cells, apparently driven by the elevated hormone levels in pregnancy, has a beneficial effect on RA patients. Instead of activating the immune system, the cells dampen it down, leading to an improvement in symptoms.”

In a related study at the Middlesex Hospital, Dr Michael Ehrenstein is preparing to look at the precise action of regulatory T cells. “We know that these cells are dysfunctional in RA patients,” he says, adding that if the precise pathway of the cells can be identified and replicated, a treatment could be developed to keep hormones artificially raised in women with RA. Dr Ehrenstein hopes that this field of research will also lead to more effective treatments for men.

Pregnancy also appears to be therapeutic for other conditions. Women who suffer migraines, for instance, often find that their symptoms either improve or disappear when they are expecting a baby. Evidence suggests a connection between migraines and fluctuations in oestrogen levels, which may be why two thirds of sufferers are women.

Often women experience their first migraine with the onset of menstruation, then find that their frequency falls with the menopause and the drop in oestrogen levels. Anne McGregor, of the Migraine Action Association, says: “Some women claim that their migraines get worse in early pregnancy, but a lot report that things improve later on. It is thought to be related to oestrogen levels becoming more stable and also to the raised levels of endorphins, the ‘feel-good hormones ’, in pregnancy.”

In a study by the Institute of Neurology in Italy, researchers found that 87 per cent of women questioned experienced a reduction in migraine symptoms during the second and third trimesters of pregnancy (compared with 47 per cent in the first). Seventy-nine per cent said that they went into complete remission during the last three months. Not that the effects were necessarily long-lasting: more than half of the sufferers reported that their migraines recurred within a month of their giving birth.

The results of a yet-to-be-published study conducted by Dr Anne McGregor, of the London Migraine Clinic and St Bartholomew’s Hospital, show, however, that oestrogen supplements are an effective means of keeping migraines permanently under control.

Up to 40 per cent of women with acne find that the condition improves after conception, although it often returns even worse when their baby is born. Likewise, many pregnant women who suffer from psoriasis — like RA, an autoimmune disease that can be influenced by female hormone levels — find their painful skin condition temporarily relieved. And mothers-to-be with Raynaud’s, a condition in which blood is temporarily prevented from reaching the body’s extremities on exposure to low temperatures, also seem to suffer less than usual.About 10 million people in the UK are affected by the condition, 90 per cent of them women. As Anne Mawdsley, chief executive of the Raynaud’s and Scleroderma Association, explains: “There does appear to be a hormonal link for some women. Many find that their Raynaud’s symptoms lessen when they have their period and some research in the 1980s confirmed this. But more investigation is needed.”

As an autoimmune disease, Raynaud’s is just one condition that may eventually benefit from research such as Dr Ehrenstein’s. He believes that understanding fully the effects of hormonal changes in pregnant women could have far-reaching benefits for a wide range of conditions.

“We want to mimic not the pregnancy but its effect on the body’s cells,” he explains. “It is feasible that our findings may be applied to other autoimmune conditions like multiple sclerosis and that, in the future, drugs could be developed accordingly.” www.arc.org.uk

If you are pregnant and would like to take part in Dr Ehrenstein’s trial, phone 020-7380 9281.

City of London Migraine Clinic www.colmc.org.uk ; Migraine Action Association www.migraine.org.uk ; Raynaud’s and Scleroderma Association www.raynauds.org.uk

Peta Bee