Q:When did research first point out the dangers of x-rays during pregnancy and links with leukemia?

The daughter of a customer has been diagnosed as having leukemia and he believes that this resulted from x-rays of the foetus. P R, Cambridgeshire County Council Library, Peterborough.....

A:According to Malepractice: How Doctors Manipulate Women, by Dr Robert Mendelsohn (Chicago, 1981), the link between leukemia and prenatal x-rays was discovered as long ago as the 1950s. By 1974, the Journal of the American Medical Association (May 1974) warned of the "potential ability of ionizing radiation to cause congenital abnormalities". The article concluded if a woman's pelvis was exposed to a high dosage of radiation (5 to 15 rads) during her first trimester of pregnancy her baby would have an increased risk of congenital abnormalities from 1 to 3 per cent. In that event, the article recommended that the woman be counselled about the prospect of a therapeutic abortion.

In his book, Stephen Fulder quotes studies showing that for every million babies exposed in the womb to even a single rad of x-rays, the equivalent of a single picture of the stomach and intestines, between 600 to 6000 will develop leukemia (The Lancet, 1985: 2:773, as reported in Stephen Fulder, How to Survive Medical Treatment, Century, 1987). That is a cancer incidence of between 0.06 to 0.6 per cent.

Whether or not an exposed child goes on to develop leukemia may depend on certain factors. One study showed that asthmatic children exposed to x-rays in utero, for instance, have a 25 times greater risk of leukemia than others so exposed (S Lock and T Smith, The Medical Risks of Life, Penguin 1976, as reported in Fulder).

Such 50 year old knowledge hasn't prevented doctors from continuing the practice. Fulder reports that one third of pregnant mothers were x-rayed in one British hospital in 1976 (The Lancet, 1976, 1: 351), while Mendelsohn describes one 1966 study revealing that a quarter of all pregnant American women were exposed to medical x-rays.

And despite warnings form the Radiological board about x-rays during pregnancy, the practice is still performed for babies lying in breech position. One of our readers was told that only an x-ray could accurately confirm that her baby would have enough room to be born vaginally; her only alternative was a caesarean section.

In fact there is a safer alternative, according to our panel member, active birth pioneer Michel Odent. Dr Odent routinely delivers breech babies at home and has the experience (rare among obstetricians) of having performed over 300 breech vaginal deliveries at his former hospital in Pithiviers, France. He suggests that labour, rather than x-rays, is a better indicator of whether a woman can give birth without assistance:

"My strategy is to consider first stage of labour as a trial to see whether the woman can give birth vaginally," he says. "If the first stage is easy, fast and straightforward, it means that she won't have problems giving birth vaginally. But if the first stage is long, difficult or seems in any way to have a problem, it's more likely that she will have problems giving birth, and so I suggest a caesarean.

"Because this is a test, the other rule is not to interfere at all with drugs to help dilate the cervix, a bath or even a birthing pool anything that would make the first stage artificially easy. "Another small point is that you can afford to be a bit more audacious when the baby is in frank breech that is, coming out buttock first. When the baby positioned feet first, there is a small risk of cord prolapse, and so I tend to be a little more careful."

With this method, four out of five women with breech babies were able to give birth vaginally at Pithiviers.

Since the problems that may arise with breech births are far more intricate than simply dimension, Dr Odent doesn't believe that x-rays provide any particularly useful information that can't be seen with the naked eye. "It's easy to see when a woman is normal and average or when she may be especially small.

And because many premature births are breech, there often is no problem with the baby fitting down the vaginal canal."

Even a late stage ultrasound scan may be redundant with an experienced practitioner, who can usually recognize with his or her hands if the baby is positioned feet first, or in frank breech.