The quality of prenatal ultrasound may be influenced by different factors. In this study, the influence of the experience of the investigator on the quality of routine ultrasound screening during pregnancy was evaluated. We related the detection rate of fetal malformations in routine ultrasound screening in the region of Vienna to the experience level of the examiner. All 323 cases of fetal malformations registered by the obstetrical departments of Vienna or registered by the Vienna perinatal mortality statistics of 1990 and 1991 were evaluated. For analysis we used the medical charts or the patient-held antenatal records ('Mutter-Kind-PaB'). Obstetricians in private offices (level I) detected 22 per cent, the examiner in the hospital (level 1-11) 40 per cent, and the examiner in the centre for prenatal diagnosis and therapy (level 111) 90 per cent of all fetal malformations. The detection rate before the 24th week of gestation was significantly different (25 per cent vs. 34 per cent vs. 58 per cent). Our results suggest that an important factor for the quality of prenatal ultrasound investigation is the education of the sonographers.
Furthermore, each pregnant woman should undergo ultrasound screening once in a level I1 or I11 centre before 24 weeks or before fetal viability.