Ultrasound in obstetrics: do the published evaluative studies justify its routine use?

A review of surveys assessing the use of ultrasound in obstetrics was undertaken to determine why this examination has spread so rapidly. Seven randomized controlled trials (RCTs) published to date as well as 182 papers published in four obstetric journals between 1979 and 1984 were reviewed. The value of routine ultrasound scanning to improve the diagnosis of intrauterine growth retardation or gestational age was demonstrated in the RCTs, but the results of the RCTs measuring the effects on health of this screening procedure did not give strong evidence for its routine use. Of the 182 papers identified, 137 were related to the diagnostic assessment of ultrasound, 14 concerned the effects on medical practice and only nine papers studied the effects of ultrasound scanning on health. Most of these 137 papers came out in favour of this procedure. Thus the spread of ultrasound scanning was based mainly on evaluative surveys which assessed its diagnostic value.