BUSINESS is brisk at Phoenix Perinatal Associates, a practice for high-risk pregnancies in Arizona. “We are solidly booked for months,” the receptionist sighs. Part of the rush comes from new guidelines published on January 2nd by the American College of Obstetricians and Gynaecologists (ACOG). These urge that all pregnant women, regardless of age, should be screened for babies with Down's syndrome.

Only women over 35 have a high risk of producing a Down's syndrome child. They have been screened through blood tests and ultrasound scans, then with amniocentesis or chorionic villus sampling (CVS), in which cells are taken from the developing embryo. Younger mums have been screened too, but in their second trimesters and only with blood tests. The new recommendation is that all women be screened at the 20th week, using the same tests; and many women are being pushed to have them earlier.

Many like the idea. The tests will be more accurate (amniocentesis has a 99% accuracy rate), and will give women more time to decide what to do. It makes sense to test under-35s: 80% of Down's syndrome babies are born to younger women, because their fertility rates are higher. But others find the changes unsettling, and with reason. Both amniocentesis and CVS tests carry a slight risk of miscarriage. And roughly 80% of women testing positive for Down's have abortions.

The new guidelines may also be triggered by the surge in lawsuits. In November an ACOG survey found that 65% of obstetrician-gynaecologists had reduced their practices for fear of liability claims. Clinic workers confirm that women who have imperfect babies tend to blame doctors. One nurse says her clinic can't afford the insurance to ward off the suits. “If more tests reduce our risks, then so be it.”

To advocates of the 350,000 Americans with Down's syndrome, all this sounds disturbing. Jon Colman, the chief operating officer at the National Down Syndrome Society (NDSS), notes that although many of them are born susceptible to heart problems, hearing loss and respiratory problems as well as mental retardation, most contribute to their families and communities and all are entitled to lead productive, independent lives. Down's children, many parents say, are delightful to bring up. And most do not die in their 20s, as Americans tend to assume, but can hope to live into their mid-50s.

Back in February, the NDSS challenged ACOG and others to make common cause with Down's syndrome organisations to give parents better information. They also urged doctors not to push expectant parents into prenatal testing, or towards abortion. But monitoring a more restrained approach might be tough. Many obstetricians are clearly overworked, with no time to offer more than suggestions and results. And although the guidelines describe these tests as options, many pregnant women are feeling badgered. Some are being asked six times or more whether they want an amniocentesis.

Asked what his goal was, one genetic counsellor in Phoenix replies: “To catch as many Down's babies” as he can. But with such eagerness, much could go wrong. Academic research suggests that around one in 100 40-year-olds produce Down's syndrome babies, but many Arizona clinics cite a figure as high as one in four. “There must be a regulated message,” says one 40-year-old new mum in Chandler. “And even then I would question it.”