... the number of diagnoses of Down's syndrome has increased by almost 71 percent from 1989-90 to 2007-08. This is mostly due to the considerable increase in the number of elder mothers over this period. Yet during the same period, the number of babies born with this condition fell by one percent because of antenatal screening and subsequent terminations.
... there has been a sharp increase of 3 to 43 percent in the proportion of younger women (below the age of 37) opting for screening. However despite improved tests, the proportion of older women deciding to be screened has stayed invariable at around 70 percent.
In the case of women with an antenatal diagnosis of Down's syndrome, the proportion who decided to terminate the pregnancy has also remained constant at around 92 percent (9 in 10).
... older women have a far greater chance of having a baby with Down's since the risk for a 40 year old mother is 16 times that for a 25 year old mother ...