Role of fetal autopsy as a complementary tool to prenatal ultrasound

Disparities Between Prenatal Ultrasound and Autopsy Findings in Pregnancies Resulting in Fetal Loss

OBJECTIVES

This retrospective study aimed to assess disparities between prenatal ultrasound and autopsy findings in pregnancies that resulted in fetal loss, and to evaluate the diagnostic performance of prenatal ultrasound using postmortem examinations as a gold standard.

METHODS

Our study included 136 autopsy cases following a fetal loss that occurred at our tertiary medical center for 8 years. A comparison between the prenatal ultrasound and autopsy findings was made, and all cases were classified according to the degree of agreement. The diagnostic performance of prenatal ultrasound was calculated at the level of organ system and specific malformations.

RESULTS

The primary sonographic diagnosis was confirmed in 91.9% of the cases (n = 125). General agreement was highest among central nervous system (CNS), cardiovascular and musculoskeletal systems (85.7%, n = 36, 18, and 12, respectively) and lowest among facial, multiple anomalies, genitourinary and gastrointestinal systems (50.0%, 74.3%, 78.6%, and 80.0%, n = 2, 26, 11, and 4, respectively). The sensitivity of ultrasound was highest in the CNS (93.2%) and musculoskeletal (87.0%) and lowest in the facial (32.3%) and pulmonary (13.0%) systems. Specifically, low diagnostic rates were noted in detecting ventriculomegaly, valvular anomalies, renal dysplasia, spleen and adrenal anomalies, and digital and facial defects.

CONCLUSIONS

Our study observed an overall high agreement between prenatal ultrasound and autopsy while contributing to our comprehensive understanding of its strengths and limitations across various types of organ systems and specific malformations.

Same performance of exome sequencing before and after fetal autopsy for congenital abnormalities: toward a paradigm shift in prenatal diagnosis?

Prenatal exome sequencing could be complex because of limited phenotypical data compared to postnatal/portmortem phenotype in fetuses affected by multiple congenital abnormalities (MCA). Here, we investigated limits of prenatal phenotype for ES interpretation thanks to a blindly reanalysis of postmortem ES data using prenatal data only in fetuses affected by MCA and harboring a (likely)pathogenic variant or a variant of unknown significance (VUS). Prenatal ES identified all causative variant previously reported by postmortem ES (22/24 (92%) and 2/24 (8%) using solo-ES and trio-ES respectively). Prenatal ES identified 5 VUS (in four fetuses). Two of them have been previously reported by postmortem ES. Prenatal ES were negative for four fetuses for which a VUS were diagnosed after autopsy. Our study suggests that prenatal phenotype is not a limitation for implementing pES in the prenatal assessment of unsolved MCA to personalize fetal medicine and could influence indication of postmortem examination.

Diagnostic accuracy of postmortem ultrasound vs postmortem 1.5-T MRI for non-invasive perinatal autopsy

OBJECTIVES

To determine the diagnostic accuracy of postmortem magnetic resonance imaging (PM-MRI) and postmortem ultrasound (PM-US) for perinatal autopsy in the same patient cohort, and to determine whether PM-US can provide the same anatomical information as PM-MRI.

METHODS

In this prospective, 5-year (July 2014-July 2019) single-center study, we performed 1.5-T PM-MRI and PM-US in an unselected cohort of perinatal deaths. The diagnostic accuracies of both modalities were calculated, using autopsy as the reference standard. As a secondary objective, the concordance rates between the two imaging modalities for the overall main diagnosis and for five anatomical regions (brain, spine, thorax, heart and abdomen) were calculated.

RESULTS

During the study period, 136 cases underwent both PM-US and PM-MRI, of which 88 (64.7%) also underwent autopsy. There was no significant difference in the rates of concordance with autopsy between the two modalities for overall diagnosis (PM-US, 86.4% (95% CI, 77.7-92.0%) vs PM-MRI, 88.6% (95% CI, 80.3-93.7%)) or in the sensitivities and specificities for individual anatomical regions. There were more non-diagnostic PM-US than PM-MRI examinations for the brain (22.8% vs 3.7%) and heart (14.7% vs 5.1%). If an 'imaging-only' autopsy had been performed, PM-US would have achieved the same diagnosis as 1.5-T PM-MRI in 86.8% (95% CI, 80.0-91.5%) of cases, with the highest rates of agreement being for spine (99.3% (95% CI, 95.9-99.9%)) and cardiac (97.3% (95% CI, 92.4-99.1%)) findings and the lowest being for brain diagnoses (85.2% (95% CI, 76.9-90.8%)).

CONCLUSION

Although there were fewer non-diagnostic cases using PM-MRI than for PM-US, the high concordance rate for overall diagnosis suggests that PM-US could be used for triaging cases when PM-MRI access is limited or unavailable. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

How does Fetal Autopsy after Pregnancy Loss or Termination for Anomalies and other Complications Change Recurrence Risk?

Objective  Historically, fetal autopsy was common after terminations for anomalies. Previous studies report that fetal autopsy confirms ultrasound findings in the majority of cases. This study aims to examine correlation between prenatal and autopsy diagnoses at University of California, San Francisco (UCSF) and evaluate whether autopsy adds diagnostic information, specifically information that changes risk of recurrence for future pregnancies. Study Design  We conducted a retrospective chart review of all fetal autopsies performed at UCSF between 1994 and 2009. Prenatal diagnosis was compared with autopsy diagnosis; for cases where there was a change in diagnosis, an MFM (maternal-fetal medicine specialist) reviewed the case to assign risk of recurrence before and after autopsy. Results  Overall, there was concordance between prenatal diagnosis and autopsy diagnosis in greater than 91.7% of cases. Autopsy added information that resulted in a change in recurrence risk in 2.3% of cases ( n  = 9). Conclusion  For the vast majority of cases, there is agreement between prenatal and autopsy diagnosis after pregnancy loss or termination for fetal anomalies. Only a small percentage of autopsies change recurrence risk. This may be useful when counseling women about method of termination and when counseling couples about whether to have an autopsy.

[Fetal autopsies : Relic or still a gold standard?]

BACKGROUND

Fetal autopsy rates are decreasing in Western countries although post-mortem examinations render important information for the parents concerning the cause of abortion and risk of recurrence in future pregnancies.

OBJECTIVE

The intention of the presented study was to analyze the development of fetal autopsies in Germany during the last decade and to review accessible information obtained by fetal autopsy.

MATERIAL AND METHODS

Reports of fetal autopsies conducted in two German university Institutes of pathology between 2005 and 2014 were evaluated retrospectively. Demographic data and the correlation between clinical diagnoses and autopsy findings were assessed. In addition, differences between spontaneous and induced cases of abortion and differences between the institutes were also documented.

RESULTS

Overall, 428 fetal autopsies were performed, whereby the number of autopsies decreased by 24.2% during the study period. Of the examined fetuses 29.7% were induced abortions which as expected exhibited different malformations compared to cases of spontaneous abortion (p < 0.001). There was no evidence of a malformation or other cause of death in 27.1% of the cases and 95.7% of these abortions occurred spontaneously. A discrepancy between clinical and autopsy findings was evident in 6.8% of cases and 3.5% of the autopsy examinations revealed at least one additional malformation compared to the prenatal clinical data.

CONCLUSION

Despite improvements in prenatal diagnostics, fetal autopsies remain an important diagnostic tool even today contributing additional information in a considerable number of cases potentially revising clinical diagnoses.

Is the diagnostic yield influenced by the indication for fetal autopsy?

The utility of fetal autopsy to corroborate antenatal ultrasound findings and to aid genetic counseling is well known. However, the ability to identify an underlying cause for the common indications for which it is performed is not well studied. This study aimed to determine if the diagnostic yield of fetal autopsy in identifying the underlying cause is determined by the indication of the autopsy. Five groups of fetuses were defined based on the indication for the autopsy performed in 903 cases: (i) malformations, (ii) intrauterine death (IUD), (iii) cystic hygroma and hydrops fetalis, (iv) isolated abnormalities of amniotic fluid, and (v) intrauterine growth restriction (IUGR). The highest diagnostic yield was in fetuses with isolated abnormalities of amniotic fluid (77%), followed by those with IUGR (75%), with IUD (69.6%), those in group five (55.2%) and lowest (45%) in fetuses with malformations (P < 0.001). A cause was identified in 77.8% fetuses with multiple malformations compared to 37.5% with isolated malformations (P < 0.001), with chromosomal abnormalities in 31.8% versus 9.9% respectively (P < 0.001) and malformation syndromes in 42.5% versus 26.3% (P < 0.001). Placental examination provided the highest yield in IUD, IUGR, and oligohydramnios (43.1%; P < 0.003) whereas chromosomal analysis was most useful in cystic hygroma/NIHF (28.9%; P < 0.001). This information on the diagnostic yield in fetal autopsy related its common indications, can be utilized to counsel families of the utility of autopsy to establish cause and recurrence risks and thereby assist then to make an informed decision to consent for the procedure. © 2016 Wiley Periodicals, Inc.

A pathologist׳s perspective on the perinatal autopsy

The perinatal autopsy is an important tool in the investigation of fetal and neonatal death, and a complete understanding of its risks and benefits is necessary for providers of perinatal care. This review, from the perspective of a perinatal pathologist, reports the details of the autopsy procedure, its goals, its value to individual patients and the health care system in general, and its alternatives. Even with new emerging technologies, the conventional perinatal autopsy remains the gold standard for determining the cause of death and the final summary of all pathologic findings. Therefore, the information provided in this review can help providers properly convey information about perinatal autopsy to bereaved families.