SCREENING FOR FOETAL ABNORMALITIES: CHROMOSOME ABNORMALITIES
In an average year chromosome abnormalities affect about 0.56 per cent or 1/200 of all live births. The most common is called Down's syndrome or mongolism and affects about one in 650 live births.
We know very little about the origin of most of them. However, there is a significant link between age of parents and the incidence of chromosome abnormality. Many doctors consider all pregnant women over the age of about thirty-five to thirty-seven to be 'at risk' and that they should be further investigated by amniocentesis. A woman's age is the most common reason for investigations to detect foetal chromosome abnormalities.
Amniocentesis and ante-natal chromosomal diagnosis should also be routinely offered when a couple have had a previous child with Down's syndrome. The most common situation is then that the risk is increased to about 1/100 of having another affected child in any future pregnancy. A few such parents may have a different risk because one of them is a carrier of a chromosome rearrangement. The risk may then vary from less than 1/100 to 100 per cent depending on the type of syndrome that affects them.
There may also be a link between a man's age, particularly if he is over forty-one, and the incidence of foetal chromosome abnormality, but the effect is believed to be smaller than that due to maternal age.
The simplicity of the age screen has led some doctors to suggest that it should be much more methodically pursued. Dr Nicholas Wald, an epidemiologist at the Radcliffe Infirmary in Oxford, claims that getting on for fifty per cent of pregnant women over the age of forty are not being offered amniocentesis. He believes that every woman over the age of thirty-five should be routinely offered it, with the option of turning it down if they don't want it. This said, it is perhaps worth adding that any age cut-off point beyond which all women are considered to be 'at risk' is something of an artificial, statistical creation.
Another category of chromosome abnormalities involves an extra or a missing sex chromosome; that is the chromosomes that determine our sex. A normal female has XX sex chromosomes, a normal male an XY combination. The four most common sex chromosome abnormalities are:
XXY Infertile males who may have some reduction of intelligence.
XXX Females with a reduced intelligence of up to fifty per cent.
XYY Tall males.
X Infertile short females.
Maternal age is of importance for the recurrence of XXX and XXY, but not for XYY and X. They are usually picked up when amniocentesis is performed to check for other conditions such as Down's syndrome.
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Women's Health
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HOW FOODS CAN PREVENT BREAST CANCER: DECREASE ESTROGENS
Here's how to counter the ill effects of bad, recycled, chemical, and free estrogens.
Bad Estrogen
Even if you produce moderate to high amounts of estrogen, there is an emerging strategy to blunt its potency. You can actually channel your estrogen into good estrogen rather than bad estrogen by eating a diet high in cruciferous vegetables. Those include cauliflower, broccoli, and cabbage. Both exercise and low body fat also increase the production of good estrogen. Alcohol, polyunsaturated fats, and too much body fat all increase the production of bad estrogen.
Recycled Estrogen
When estrogen is transported from the bloodstream through the liver and into the bowel for disposal, it is assisted by large amounts of fiber in the bowel. That fiber binds to estrogen in the intestine so that the body cannot reabsorb it, ensuring that it is excreted with other waste products. However, when there is too little fiber in the diet, the estrogen remains free in the bowel and may be reabsorbed by the body into the bloodstream, raising the amount of estrogen in the bloodstream. A study at Tufts University showed that the more a woman's bowel movement weighed, the lower was her blood estrogen level. The assumption is that the increased weight of the bowel movement was due to the fiber.
Free Estrogen
The most effective way to decrease the amount of free estrogen in the blood is to build more of the carriers that bind estrogen in the blood and keep it from estrogen receptors. Lets look at the key strategies. The prime regulator of estrogen carriers is the hormone insulin, according to Banoo Parpia of the China-Cornell-Oxford Project. The lower you can drop your insulin, the more estrogen carriers your body manufactures. A low-fat diet also reduces the amount of free estrogen in healthy postmenopausal women. Soy also manufactures more carriers. A high-fiber diet helps to bind more free estrogen in your blood and keeps it at lower, safer levels. Many of these measures also decrease estrogen production, so you are cutting your cancer risk in at least two separate ways.
Chemical Estrogen
The most aggressive prevention includes avoiding animal and fish products with high fat contents that can pick up and concentrate large quantities of chemical estrogens and pesticides. The worst offenders and how to avoid them are found in the chapter "Step 8: Avoid Chemical Estrogens." Eating organic foods that have always been pesticide-free will help you to avoid contaminating breast fat. Washing all fruits and vegetables thoroughly will help remove pesticides. Since most women already have high stores of chemical estrogens in their breast fats there are two other strategies that have proved to be beneficial. First is breast-feeding, which flushes pesticides out of their storage site in breast fat. That does mean that your infant ingests milk with chemical estrogens, but pediatricians do not believe this is harmful. The most practical strategy of all is to consume large amounts of estrogen blockers such as soy, which block the effect of these chemicals at the estrogen receptors on breast cells.
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Womens health
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