A correlative study of prenatal ultrasound and post-mortem findings in fetuses and infants with an abnormal karyotype

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 Nationa l Center for Fetal Medicine (NCFM), an abnormal karyotype, and an autopsy p erformed 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 incases with trisomy 1 3 and 18; congenital heart defects (CHD) were most prevalent among fetuses with trisomy 18. In 80% of cases there was full agreement between the ultra sound and autopsy findings; in another 8% of cases there was nearly complet e concordance. Thus, in 88% of cases, the main prenatal sonographic diagnos is was correct. In 6% major autopsy findings were not detected by ultrasoun d examination, in 1% none of the autopsy findings were detected by routine ultrasound and in 5% ultrasound findings were not verified at autopsy. Wher e 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 u ltrasound diagnoses in fetuses with trisomy 21 with the main diagnosis corr ect in 96%; for trisomy 18 the concordance was less good, with the main dia gnosis correct in 71%. Conclusion The present comparison of sonographic diagnoses with post-mortem findings demonstrated good accordance between the two methods. It also dem onstrates the importance of awareness of the anomalies known to occur with different aneuploidies.