Post-mortem apparent resolution of fetal ventriculomegaly: evidence from magnetic resonance imaging.

ABSTRACT

OBJECTIVE: This study aims to determine the accuracy of post-mortem magnetic resonance imaging (MRI) and autopsy for confirmation of sonographically detected fetal ventriculomegaly. METHODS: This study uses retrospective review of fetuses with sonographically diagnosed ventriculomegaly, where the pregnancy was terminated and post-mortem examination was performed during a period in which post-mortem MRI was being offered. RESULTS: Sixteen cases were identified. In nine (56%), autopsy and/or post-mortem MRI confirmed the prenatal findings. In the other seven, both autopsy and post-mortem MRI demonstrated no ventriculomegaly, but antenatal MRI confirmed the ultrasound findings in 6/7 cases where it had been performed. Post-mortem investigations confirmed antenatal findings in 8/9 cases with severe ventriculomegaly (posterior horn measurement >15 mm), whereas only 2/7 in which ventriculomegaly was not confirmed had severe ventriculomegaly. CONCLUSIONS: Post-mortem examination, both by traditional neuropathological examination, and post-mortem MRI may fail to confirm prenatal ventriculomegaly in around half of cases. The post-mortem MRI findings indicate that this is due to resolution of ventriculomegaly rather than autopsy artefact, and is presumably a consequence of post-mortem fluid redistribution. Parents should be advised before termination of pregnancy that post-mortem confirmation of ventriculomegaly, especially in mild cases, may not be possible. Antenatal MRI may be a better approach for confirming prenatal ultrasound findings.