Less invasive autopsy: benefits and limitations of the use of magnetic resonance imaging in the perinatal postmortem.

The decline in the postmortem (PM) autopsy rate in the United Kingdom paralleled the change in public perception of this procedure after the organ retention crisis in 2000. The introduction of magnetic resonance imaging (MRI) in the fetal, perinatal, and pediatric autopsy led some investigators to propose that MRI could replace the conventional PM. We assessed the role of MRI in fetal autopsy as an addition or a potential replacement method to the conventional PM and to evaluate the benefits and limitations of each technique. We retrospectively reviewed the PM and MRI examination of 100 fetuses. The MRI was limited to the brain or brain and spinal cord. Forty-six cases involved termination of pregnancy; 30 were intrauterine fetal deaths/stillbirths; 16 were premature deliveries followed by neonatal death; and 8 were miscarriages. The mean gestational age of all cases was 25.54 weeks (range: 13-41 weeks). In 54 of the 90 full PMs, there was a complete agreement between the MRI and autopsy findings on the morphology of the brain and spine. Despite this agreement, the information gained at the PM was relevant to find the cause or mechanism of death in 20 of 54 cases (37%). In 24 autopsies the MRI added valuable information to the autopsy. However, if MRI had been the only investigation, essential information would have been lost in 17 of 24 cases (71%). In 12 cases the PM was clearly superior to the MRI. The integrated result obtained from the traditional autopsy remains crucial in determining the cause or mechanism of the malformation or of the fetal/perinatal death and accordingly is important for the counseling offered to parents regarding the recurrence risk for future pregnancies.