Post-mortem perinatal imaging: what is the evidence?

Abstract

Post-mortem imaging for the investigation of perinatal deaths is an acceptable tool amongst parents and religious groups, enabling a less invasive autopsy examination. Nevertheless, availability is scarce nationwide, and there is some debate amongst radiologists regarding the best practice and optimal protocols for performing such studies. Much of the published literature to date focusses on single centre experiences or interesting case reports. Diagnostic accuracy studies are available for a variety of individual imaging modalities (e.g., post-mortem CT, MRI, ultrasound and micro-CT), however assimilating this information is important when attempting to start a local service. In this article, we present a comprehensive review summarising the latest research, recently published international guidelines, and describe which imaging modalities are best suited for specific indications. When the antenatal clinical findings are not supported by the post-mortem imaging, we also suggest how and when an invasive autopsy may be considered. In general, a collaborative working relationship within a multidisciplinary team (consisting of radiologists, radiographers, the local pathology department, mortuary staff, fetal medicine specialists, obstetricians and bereavement midwives) is vital for a successful service.

Fetal Autopsy: Improving Clinicians’ Knowledge to Increase Parents’ Acceptance. A Prospective Questionnaire-Based Study

“…Recently, the possibility of minimally invasive postmortem examinations has been suggested as an opportunity of investigation, aimed at determining the cause of fetal death if a full post-mortem is not accepted [3]. Some Authors also provided protocols for post-mortem imaging (including post-mortem ultrasound, radiographs, computerized tomography, magnetic resonance) that can be used when the proposal of the autoptic post-mortem examination is declined [16]. However, parents should be informed about the risk of missing important findings when a full autopsy is not performed [3].…”

Less‐invasive autopsy for early pregnancy loss

“…47,73,[78][79][80][81] However, PMUS is operatordependent, requiring specialist training to develop the skills and experience to accurately identify possible causes of pregnancy loss in these smaller fetuses. 47,51,61,74 A high-resolution linear or curvilinear probe is advised given the small fetal size. The loss of normal live tissue rigidity can lead to slumping and difficulty maintaining contact with the ultrasound probe, and so a 'water bath' technique has been described, where the whole fetus is fully immersed within a cold, still water bath with a gel stabilising pad.…”

“…To challenge the declining consent rate, less‐invasive autopsy (LIA) techniques, such as laparoscopic examination of the internal organs through smaller incisions or imaging techniques alone, have been developed in recent years, providing a greater and more acceptable choice to parents 10,13,14,27,28,37,39,41–44 . Significant challenges remain in identifying the cause of fetal demise <20 weeks gestational age (GA) or <500 g, as routine imaging techniques (magnetic resonance imaging (MRI), computed tomography (CT), ultrasound, radiographs) cannot provide sufficient resolution, tissue contrast, or soft tissue detail 41,45–49 . It should also be noted that identifying abnormalities in early gestation through CA also remains challenging 47,48,50–57 .…”

“…HF‐MRI typically takes longer scanning times (>18 h), making it difficult to implement in a clinical setting, 47,55,70,83 and may be more expensive than Micro‐CT (400 Euros per patient in comparison to 200 Euros for micro‐CT) 71 . Most HF‐MRI scanners have a small‐bore size (16–30 cm diameter), thus limiting the field‐of‐view, to smaller fetuses 55 .…”

“…10,13,14,27,28,37,39,[41][42][43][44] Significant challenges remain in identifying the cause of fetal demise <20 weeks gestational age (GA) or <500 g, as routine imaging techniques (magnetic resonance imaging (MRI), computed tomography (CT), ultrasound, radiographs) cannot provide sufficient resolution, tissue contrast, or soft tissue detail. 41,[45][46][47][48][49] It should also be noted that identifying abnormalities in early gestation through CA also remains challenging. 47,48,[50][51][52][53][54][55][56][57] Several terms are commonly used to describe the different post-mortem approaches towards diagnosis, and it is important to understand the investigations each term refers to and what can be achieved (Table 1).…”