Unless there is a specific increase in risk of abnormality because of past history, tests in pregnancy are offered as screening for abnormalities. These tests should be explained as such and parents should not be offered, or accept, them as "routine".
Even an early scan to confirm the stage of a pregnancy should only be offered with the proviso that there is a chance of detecting signs which may be associated with foetal abnormalities, even though they are not performed for this reason before 16 weeks in most of the country.
Under these circumstances, parents have the opportunity to accept testing if they understand the implications and want to know the results. Parents seek reassurance of normality, which can never be assured. All screening tests imply a possible need for subsequent diagnostic investigations and perhaps intervention, even though most babies will be normal in the end. If parents do not wish to run the risk of finding potential signs of abnormality, then they need not accept testing.
Senior Registrar in Obstetrics and Gynaecology