Early screening for fetal cardiac anomalies by transvaginal echocardiography in an unselected population: the role of operator experience

Objectives To examine the accuracy of early transvaginal fecal echocardiogr aphy performed in an unselected population by operators with different leve ls of experience and to compare the results with those obtained from a refe rral population. Design Prospective study. Methods A series of 4785 unselected fetuses and 221 referred fetuses were s creened at 13-15 weeks' gestational age by transvaginal echocardiography. F or each fetus, visualization of the four-chamber view plus the origin of th e great arteries was attempted Color Doppler imaging was only performed in cases of cardiac malformations already identified by two-dimensional echoca rdiography. The scans were performed by seven operators with different leve ls of experience. Reliability was assessed by conventional transabdominal e chocardiography at 20-22 weeks, by postnatal follow-up in the first 3 month s of life, and/or by autopsy in all cases of termination or fetal death. Results The rate of complete visualization (four-chamber view plus great ar teries) was 47.5% in the unselected population, and 76.9% in the referral p opulation. There were four (0.08%) true positives among the unselected fetu ses, and five (2.3%) among referrals, mostly with enlarged nuchal transluce ncy or other malformations. Among the unselected fetuses, nine false negati ves were detected by transabdominal echocardiography. Improvement in the op erators' ability to recognize cardiac anomalies in unselected population wa s disappointing and was influenced more by individual approach than by the number of examinations performed. Conclusions Early screening for cardiac a nomalies among unselected fetuses is ill-advisable. The usefulness of an ea rly approach is confirmed in high risk fetuses or in the presence of enlarg ed nuchal translucency when Performed by expert operators.