Correlation between ultrasound and autopsy findings after 2nd trimester terminations of pregnancy

To compare ultrasound (US) and fetal autopsy findings in 2(nd) trimester termination of pregnancy because of structural fetal anomalies.

A total of 112 terminations of pregnancy (TOP) between 1999-2003 were reviewed retrospectively. The cases originated from a secondary and a tertiary Fetal Medicine unit in the south Stockholm area, using a common specialized perinatal pathology service. Karyotype was not known at the time of US examination. The findings were compared and classified into four groups according to the degree of agreement between US and autopsy.

In 45% of cases there was total agreement between US and autopsy. In 40%, autopsy confirmed all US findings but provided additional information of clinical importance. Partial or total lack of agreement was noted in 11% and 4% of the cases, respectively. Areas of discrepancy involved mainly CNS- and cardiovascular abnormalities and, to a lesser extent, renal anomalies, abdominal wall defects and hydrops/hygroma. Regarding CNS abnormalities the overall rate of agreement was 62%; it was highest in acrania/anencephaly (92%) and lowest in hydrocephaly (39%).

We find an overall high degree of agreement between US and autopsy findings. Autopsy often provided additional information of clinical value and it should always follow US examination and TOP. Fixation of CNS is crucial for optimal results. Specific limitations of autopsy, i.e., detection of CNS abnormalities, may be reduced by complementary imaging techniques, such as MRI. The ability of US to detect cardiac anomalies is enhanced with the close contact to specialized fetal cardiology.