Correlation between ultrasound diagnosis and autopsy findings of fetal malformations.

Objective: to compare ultrasound (US) and autopsy findings of fetal malformations in second trimester terminations of pregnancy to evaluate the degree of agreement between US and fetal autopsy.

Methods: in this study, all second trimester termination of pregnancy between 2003-2010 were considered. US and autopsy findings were compared and all cases were classified into five categories according to the degree of agreement between US and pathology (A1: full agreement between US and autopsy; A2: autopsy confirmed all US findings but revealed additional anomalies 'rarely detectable' prenatally; B: autopsy demonstrated all US findings but revealed additional anomalies 'detectable' prenatally; C: US findings were only partially demonstrated at fetal autopsy; D: total disagreement between US and autopsy).

Results: 144 cases were selected. In 49% of cases there was total agreement between US and autopsy diagnosis (A1). In 22% of cases additional information were about anomalies 'not detectable' by US (A2). In 12% of cases autopsy provided additional information about anomalies not observed but 'detectable' by US (B). In 13% of cases some anomalies revealed at US, such as valve insufficiencies, pericardial and pleural effusions, were not verified at autopsy (C). Total lack of agreement was noted only in 4% of cases (D). Main areas of disagreement concerned cardiovascular, CNS and complex malformations. The degree of agreement was higher if malformations were diagnosed in a tertiary center.

Conclusions: this study shows an overall high degree of agreement between definitive US and autopsy findings in second trimester termination of pregnancy for fetal malformations. Autopsy reveals to be the best tool to diagnose malformations and often showed other abnormalities of clinical importance not detected by US, but sometimes also US could provide additional information about functional anomalies because US is a dynamic examination.