Objective: To compare ultrasound and post-mortem findings in 98 fetuses and infants with an abnormal karyotype.
Design: Criteria for inclusion were an ultrasound examination at the National Center for Fetal Medicine (NCFM), an abnormal karyotype, and an autopsy performed during the period 1985-94.
Results: Trisomy 18 and 21 were the two most common abnormal karyotypes. The highest number of congenital anomalies was observed in cases with trisomy 13 and 18; congenital heart defects (CHD) were most prevalent among fetuses with trisomy 18. In 80% of cases there was full agreement between the ultrasound and autopsy findings; in another 8% of cases there was nearly complete concordance. Thus, in 88% of cases, the main prenatal sonographic diagnosis was correct. In 6% major autopsy findings were not detected by ultrasound examination, in 1% none of the autopsy findings were detected by routine ultrasound and in 5% ultrasound findings were not verified at autopsy. Where the correlation was related to individual autosomal trisomies, structural anomalies were most often correctly diagnosed in fetuses with trisomy 13, with the main diagnosis correct in all cases; second in accuracy were the ultrasound diagnoses in fetuses with trisomy 21 with the main diagnosis correct in 96%; for trisomy 18 the concordance was less good, with the main diagnosis correct in 71%.
Conclusion: The present comparison of sonographic diagnoses with post-mortem findings demonstrates good accordance between the two methods. It also demonstrates the importance of awareness of the anomalies known to occur with different aneuploidies.