Debate about ultrasound screening policies

Routine ultrasound examination is defined as a screening procedure performed on the total obstetric population usually at 18-20 weeks of gestation as opposed to the selective use of ultrasound that might provide more information for a problem that is suspected on clinical grounds. Standard ultrasound examination includes a comprehensive examination of fetal anatomy as part of routine ultrasound. It is important for the clinician to realise that the comprehensive examination of fetal anatomy is an essential, not optional, part of the routine examination. Screening may lead to unnecessary anxiety if there is a false-positive result, or to a false sense of security if there is a false-negative result. The routine offering of obstetric ultrasound screening is the central issue in the general question of whether every woman should receive an obstetric ultrasound examination. The majority of countries have adopted the following diagnostic strategy. All pregnancies must be ultrasonographically tested in accordance with the protocols commonly recommended. The ultrasonography done at 18-20 weeks, which is known to be fundamental for diagnosing prenatal malformations, must always be performed at level II. Highrisk pregnancies of malformations are to be selected in the first level of screening and referred to level II for further study. There is extensive literature neither supporting an improvement in perinatal morbidity or mortality nor an overall :reduction in unnecessary intervention with routine ultrasound. The role of routine ultrasonography and its validity as a screening test for fetal malformation in a low-risk population is still the object of debate.