Abstracts of the 14th World Congress on Ultrasound in Obstetrics and Gynecology. 31 August-4 September 2004, Stockholm, Sweden.

Abstract

To evaluate the impact of the examiner's ultrasound experience at the second trimester fetal examination, with emphasise on the fetal heart examination and the detection rate of critical congenital heart defects (CHD's). From February 1991 to December 2001, 29 026 pregnant women from a well-defined non-selected population received a second trimester fetal examination performed by nurse/midwives specially trained in obstetric ultrasound. One group of examiners who had performed more than 2000 routine examinations was compared to a group of examiners with 200–2000 performed examinations in addition to their basic ultrasound training. The fetal heart examination included the four-chamber view and the great arteries. During the first 5 years of the study period, the views obtained were prospectively registered in detail. Mean gestational age at routine exam was 18.3 (range 16–22) weeks. The experienced examiner showed significantly better results in obtaining the four-chamber view and the outlets than did the less experienced, 75 and 36%, respectively. The total detection rate of CHD's was 50% for experienced and 33% for less experienced examiners; for isolated CHD's, 44% versus 27% and CHD's with associated malformations 56% versus 37%, respectively. The learning curve for obtaining the four-chamber view and the outlets was approximately 2 years. Based on the 29 026 routine fetal examinations, a significant correlation was found between the level of experience of the examiners and the detection rate of critical congenital heart defects. This strongly indicates that a major focus on teaching and training is needed to improve the worldwide insufficient detection rate of fetal heart defects at the second trimester routine fetal examination.