The antenatal clinics in the catchment area of the Department of Obstetrics and Gynecology, University Hospital, Lund, were divided into a study group and a control group. At the study antenatal clinics during a 15-month period 1,004 pregnant women received a written and verbal information that a routine ultrasound examination during gestational week 18 should be considered as a prenatal diagnostic method. They even got information on alternatives: to decline all, to have an early abdominal ultrasound examination, or to have both a routine ultrasound examination and an amniocentesis performed. At the control antenatal clinics, 1,408 pregnant women received standard information. No women in either group chose not to have an ultrasound examination performed, but 1% chose an early abdominal examination in the study group. The percentage of women older than 35 years who asked for an amniocentesis was equal in the two groups. However, women younger than 35 years in the study group requested amniocentesis significantly more frequently than the women in the control group.