A study in the BMJ has confirmed that more effective prenatal screening has contained the growth in the number of Down syndrome children in Britain. Even though the number of births in 1989/90 was roughly the same as 2007/08, antenatal and postnatal diagnoses of Down’s syndrome increased by 71% to 1,843. The number of live births with Down syndrome, however, actually fell by 1% because more women had antenatal screening and subsequently terminated the child.

Without the screening, the number of Down syndrome children in the UK would have soared by 48% because of the growing numbers of older mothers. The improved screening is making a difference, especially amongst younger women. Among mothers aged 37 years and older, a consistent 70% of affected pregnancies were diagnosed before birth. But among younger mothers, the proportions of pregnancies diagnosed before birth increased from 3% to 43% . Studies have shown that about 92% of women who are told that their child will have Down syndrome go on to have a termination.

Writing in the blog of Oxford University's Oxford Uehiro Centre for Practical Ethics, Lachlan de Crespigny says that this is not a bad thing, although he acknowledges that Down syndrome children often have sunny dispositions. "But few people choose to have a Down syndrome child. It is hard to find adoptive parents for a DS child. Couples with a previous DS child usually have prenatal testing to minimize the risk of having another disabled child and they proceed to abortion of an affected fetus." He says that the advent of risk-free prenatal tests should be celebrated. Dr de Crespigny is a distinguished Australian expert in prenatal testing. ~ BMJ, Oct 26; Practical Ethics, Oct 25