Conventional vs virtual autopsy with postmortem MRI in phenotypic characterization of stillbirths and fetal malformations

What is it about?

Pregnancies are complicated by fetal deaths in more than 7200 cases everyday globally. The loss of a fetus is devastating to the expecting parents and often want to know, the cause of death and if there is any increased risk in the future pregnancies. The autopsy or postmortem examination remains the gold standard investigation for the evaluation of fetal death. It provides valuable information regarding the cause of fetal death, which is of relevance for genetic counseling and management of future pregnancies. It also helps the physicians to understand the cause of fetal death and guides advancement in future research. Fetal postmortem examination rates have steadily declined over recent years due to lack of parental consent, lack of experts, practical difficulties of performing postmortem brain examination, cost containment, healthcare professionals not requesting for postmortem examination. Hence it has become important to find acceptable alternatives to the conventional autopsy. Whole body MRI of the fetus after death has been studied by many researchers from western countries and has produced acceptable results comparable to that of conventional autopsy. The focus of our study was to compare the conventional autopsy with the whole body postmortem-MRI in fetal deaths ≥ 20 weeks of pregnancy. We enrolled 43 fetuses after parental consent for both conventional autopsy and postmortem-MRI after excluding maternal and pregnancy complications of fetal death. Whole body postmortem-MRI followed by conventional autopsy was performed in all the fetuses and findings were compared. Radiologists and Pathologists were blinded to each other’s findings. Results showed findings based on the postmortem-MRI was concordant with that of conventional autopsy in 35 out of 43 fetuses. Postmortem-MRI was better at detecting brain, spinal cord, lung and kidney birth defects and was poor at detecting heart, abdomen and muscle and bony defects compared to the conventional autopsy. Postmortem-MRI along with ancillary tests like prenatal ultrasonogram, placental examination, external examination of fetus, whole body X-ray, examination of genetic material and other relevant tests, can be an acceptable alternative to conventional autopsy when refused in the evaluation of fetal death and conventional autopsy must be performed when suspecting cardiac defects. Conventional autopsy remains the gold standard investigation, when it is of adequate quality. Hence obtaining information from other sources like postmortem-MRI becomes important, when conventional autopsy is not adequate like in maceration. Also postmortem-MRI is better at detecting brain and spinal cord defects and is more acceptable to the parents.

Featured Image