Over the last two decades, the number of couples experiencing fertility problems has risen significantly. A quarter of all couples planning a baby have trouble conceiving. One in four women miscarries. Some experience repeated miscarriages as often as 10 times.

Of the couples who seek medical help, 30 per cent are told they have 'unexplained infertility' for which the doctors can offer no treatment. If one in four pregnancies ends in early miscarriage, should we accept this high rate as 'normal'? Arthritis is very common in our society as we get older; in other cultures it is not. Does this make it 'normal'? Or are there ways of preventing arthritis by looking at our lifestyle?

One reason why so many couples are diagnosed with unexplained infertility is that doctors cannot put it down to a specific, observable medical cause. But infertility is a multifactorial problem and should be investigated that way. That means looking at a variety of issues such as nutrition, alcohol and smoking habits, levels of lead and other toxic metals, pesticides, food additives, genitourinary infections, allergies, stress and other hazards of modern life. That means your partner also needs to take a close look at his health and nutrition as well (since in four out of ten cases of infertility, the problems are on the male side). The fact is that our modern 'unnatural' life style, combined with the nutrient depletion of much of our food, has left many of us deficient in the vitamins and minerals we need for successful babymaking.

There's no doubt that risk of miscarriage increases as we get older. Before the age of 40, the risk of miscarriage is about 15 per cent, and it can rise to about 40 per cent in women over the age of 40, mostly because of genetic abnormalities.

Chromosomal problems

Chromosomal abnormalities are the most common reason for a miscarriage and are usually the result of a one off genetic abnormality in the baby that is unlikely to recur. In other words, Nature is working according to the law of survival of the fittest. When the baby is abnormal, it will try to stop that pregnancy continuing. It is thought that up to half of all miscarriages are due to a genetic abnormality.

The most common chromosomal abnormality diagnosed is a situation where there are three chromosomes in the pair instead of two. Depending on which chromosome pair this happens to, it will give rise to a specific abnormality. Not all abnormalities always end in a miscarriage. For instance, Down's syndrome is caused by an extra chromosome on pair number 21 and for that reason is also called trisomy 21. It is thought that most trisomies are caused by an abnormal division in the egg that occurs before fertilisation.

This may explain why older women have always been thought to have a higher risk of having a Down's syndrome baby, since older women's eggs are more likely to be abnormal. But the Down's Syndrome Association claims that eight out of ten babies with Down's syndrome are born to mothers under the age of 35. The extra chromosome can also come from the man's sperm. So, at the moment, scientists cannot say with any certainty precisely what causes Down's syndrome.

However, there are links between Down's syndrome and mineral deficiencies. For example, people with Down's children have lower levels of zinc and selenium compared with others of the same age (Biol Trace Element Res, 1996; 54: 201-6). It has also been found that, in Down's syndrome, blood levels of the 'antioxidant defence system' enzymes (superoxide dismutase and glutathione peroxidase) are overproduced. Both these enzymes are produced by the body to disarm free radicals. The building blocks for these enzymes include the minerals zinc and selenium.