Quality control of prenatal sonography in detecting trisomy 18. The value of perinatal autopsy

Are non-invasive or minimally invasive autopsy techniques for detecting cause of death in prenates, neonates and infants accurate? A systematic review of diagnostic test accuracy

OBJECTIVES

To assess the diagnostic accuracy of non-invasive or minimally invasive autopsy techniques in deaths under 1 year of age.

DESIGN

This is a systematic review of diagnostic test accuracy. The protocol is registered on PROSPERO.

PARTICIPANTS

Deaths from conception to one adjusted year of age.

SEARCH METHODS

MEDLINE (Ovid), EMBASE (Ovid), CINAHL (EBSCO), the Cochrane Library, Scopus and grey literature sources were searched from inception to November 2021.

DIAGNOSTIC TESTS

Non-invasive or minimally invasive diagnostic tests as an alternative to traditional autopsy.

DATA COLLECTION AND ANALYSIS

Studies were included if participants were under one adjusted year of age, with index tests conducted prior to the reference standard.Data were extracted from eligible studies using piloted forms. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2. A narrative synthesis was conducted following the Synthesis without Meta-Analysis guidelines. Vote counting was used to assess the direction of effect.

MAIN OUTCOME MEASURES

Direction of effect was expressed as percentage of patients per study.

FINDINGS

We included 54 direct evidence studies (68 articles/trials), encompassing 3268 cases and eight index tests. The direction of effect was positive for postmortem ultrasound and antenatal echography, although with varying levels of success. Conversely, the direction of effect was against virtual autopsy. For the remaining tests, the direction of effect was inconclusive.A further 134 indirect evidence studies (135 articles/trials) were included, encompassing 6242 perinatal cases. The addition of these results had minimal impact on the direct findings yet did reveal other techniques, which may be favourable alternatives to autopsy.Seven trial registrations were included but yielded no results.

CONCLUSIONS

Current evidence is insufficient to make firm conclusions about the generalised use of non-invasive or minimally invasive autopsy techniques in relation to all perinatal population groups.PROSPERO registration numberCRD42021223254.

Induction of labor compared to dilation and evacuation for postmortem analysis

OBJECTIVE

This study aimed to evaluate the ability to obtain autopsy and cytogenetics after midtrimester termination.

METHODS

A retrospective cohort study of women undergoing termination, via induction or dilation and evacuation (D&E), at 16 0/7-23 6/7 weeks was performed. Exclusion criteria were elective termination, preterm labor, PPROM, and no autopsy or cytogenetic exam performed. The ability to obtain cytogenetics and autopsy as well as complications rates were compared between the two groups with Chi-square tests.

RESULTS

Of the 469 women who met the inclusion criteria, 158 had an induction and 312 had a D&E. The induction of labor group had higher mean gestational ages, p < 0.01. Successful autopsy was more likely in the induction group, 94.3%, versus D&E group, 34.7%, p = 0.01. There was no difference in ability to obtain cytogenetics between the two groups, 89.1% in the induction group, and 92.3% in D&E group, p = 0.4. There was a difference in the total complication rates between the groups, 9.8% (26) in the induction versus 6.4% (20) in the D&E group, p < 0.01; however, there was no difference in major complications.

CONCLUSIONS

Midtrimester terminations by induction were more likely to have successful autopsies when compared with D&E. The ability to obtain cytogenetics was similar regardless of termination mode.

Trissomia 18: revisão dos aspectos clínicos, etiológicos, prognósticos e éticos

OBJETIVO: Revisar as características clínicas, etiológicas, diagnósticas e prognósticas da trissomia do cromossomo 18 (síndrome de Edwards). FONTES DE DADOS: Foram pesquisados artigos científicos presentes nos portais MedLine, Lilacs e SciELO, utilizando-se os descritores 'trisomy 18' e 'Edwards syndrome'. A pesquisa não se limitou a um período determinado e englobou artigos presentes nestes bancos de dados. SÍNTESE DOS DADOS: A síndrome de Edwards é uma doença caracterizada por um quadro clínico amplo e prognóstico bastante reservado. Há descrição na literatura de mais de 130 anomalias diferentes, as quais podem envolver praticamente todos os órgãos e sistemas. Seus achados são resultantes da presença de três cópias do cromossomo 18. A principal constituição cromossômica observada entre estes pacientes é a trissomia livre do cromossomo 18, que se associa ao fenômeno de não disjunção, especialmente na gametogênese materna. A maioria dos fetos com síndrome de Edwards acaba indo a óbito durante a vida embrionária e fetal. A mediana de sobrevida entre nascidos vivos tem usualmente variado entre 2,5 e 14,5 dias. CONCLUSÕES: O conhecimento do quadro clínico e do prognóstico dos pacientes com a síndrome de Edwards tem grande importância no que diz respeito aos cuidados neonatais e à decisão de instituir ou não tratamentos invasivos. A rapidez na confirmação do diagnóstico é importante para a tomada de decisões referentes às condutas médicas. Muitas vezes, as intervenções são realizadas em condições de emergência, sem muita oportunidade de reflexão ou discussão, e envolvem questões médicas e éticas difíceis.

Comparison of prenatal ultrasound findings and autopsy findings in fetuses terminated after prenatal diagnosis of malformations: an experience of a clinical genetics center

OBJECTIVE

To compare antenatal diagnosis with post mortem examination findings in the pregnancies terminated after prenatal detection of anomalies and to evaluate the potential benefits of post mortem examination for counseling regarding the risk of recurrence.

METHODS

This is a retrospective study over a 7-year period from 2001 to 2007. Pregnancies terminated after prenatal identification of fetal malformation were evaluated by post mortem examination of 91 fetuses.

RESULTS

Fetal autopsy provided a definite diagnosis in 72/91 (79.1%) of the cases. Fetal autopsy confirmed the sonographic findings in 89 of 91 cases (97.8%). In 66 (72.5%) cases there was complete concordance between prenatal and autopsy findings, while in 23 cases there was major concordance. There were 49 cases with isolated malformations, 41 cases with multiple (89) malformations, and, in one case, no malformation was found at autopsy. Of the 89 associated malformations, 39 (43.8%) were detected prenatally and 50 (56.2%) were detected on fetal autopsy. The additional malformations detected on autopsy included 38 major and 12 minor malformations Additional findings helped in redefining the diagnosis and the risk of recurrence in 30 of 91 (33%) cases.

CONCLUSION

The present study emphasizes the importance of autopsy in providing accurate etiologic diagnosis necessary for genetic counseling.

Sonographic findings of trisomy 18 in the second trimester of pregnancy

OBJECTIVE

The purpose of this study was to examine the sonographic findings in fetuses with trisomy 18 in the second trimester of pregnancy.

METHODS

A retrospective review of the cytogenetic laboratory databases at 6 tertiary referral centers identified all cases of trisomy 18. The prenatal sonographic studies in fetuses at 15 to 21 weeks' gestation, done before invasive testing for the karyotype, were reviewed for anatomic and biometric findings. We defined abnormal fetal biometric findings as a biometric measurement (biparietal diameter, abdominal circumference, or femur length) below the fifth percentile in the second trimester.

RESULTS

Of 98 fetuses with trisomy 18, 95 (97%) were detected sonographically; an anomaly was found in 92 (94%). A biometric measurement below the fifth percentile was noted in 50 (51%). Cardiac (63%) and central nervous system (34%) anomalies were most frequently detected. Although choroid plexus cysts were commonly seen, no fetuses with trisomy 18 and isolated choroid plexus cysts were found.

CONCLUSIONS

Targeted sonography identified abnormal fetal anatomy or abnormal biometric findings in 97% of fetuses with trisomy 18 in the second trimester. A biometric measurement below the fifth percentile was noted in half of the cases in the second trimester.

Three- and 4-dimensional ultrasonography in the prenatal evaluation of fetal anomalies associated with trisomy 18

OBJECTIVE

The purpose of this study was to assess the usefulness of 3- and 4-dimensional ultrasonography (3D/4DUS) for the description of anomalies associated with trisomy 18 and to determine whether 3D/4DUS adds diagnostic information over what is provided by conventional 2-dimensional ultrasonography (2DUS) alone.

METHODS

Twenty-six fetuses subsequently proven to have trisomy 18 underwent prenatal ultrasonographic evaluations by both 2DUS and 3D/4DUS. Volume data sets were acquired by the same sonographers after the conventional 2DUS examinations and were explored with 4-dimensional imaging software by another independent examiner blinded to the indications of 2DUS. The findings detected by 2DUS and 3D/4DUS were compared with those acquired at autopsy. The sensitivity of each modality for detecting anomalies was calculated and compared by the McNemar test.

RESULTS

Excluding polyhydramnios, there were 131 anomalies confirmed postnatally in 26 fetuses with trisomy 18. There was a statistically significant difference in the sensitivity for detecting anomalies between 3D/4DUS and 2DUS (93.89% versus 73.28%; McNemar value = 23.31; P < .05), especially in anomalies of the face/neck (96.15% versus 65.38%; McNemar value = 6.13; P < .05) and extremities (96.3% versus 48.15%; McNemar value = 11.07; P < .05). Three- and 4-dimensional ultrasonography provided additional diagnostic information for 83.97% of the anomalies related to trisomy 18 and influenced the obstetric management of 4 fetuses.

CONCLUSIONS

Three- and 4-dimensional ultrasonography offered diagnostic advantages for many anomalies associated with trisomy 18, especially for anomalies of the extremities and face. This modality could be a powerful adjunct to 2DUS in the prenatal anatomic evaluation of fetuses with trisomy 18.

The role of perinatal autopsy in the management of pregnancies with major fetal trisomies

We assessed the value of perinatal autopsy following mid-trimester termination of pregnancy due to major fetal trisomies. Singleton fetuses (n=305) that underwent prenatal sonography and karyotyping during the second trimester of pregnancy and that had trisomy 21, trisomy 18, or trisomy 13 constituted the study population. The findings of second trimester sonography and fetal autopsy were compared. Altogether, 611 separate major structural malformations were diagnosed during autopsy. Full agreement was achieved between sonography and autopsy in 35.8% of the malformations. The additional findings at autopsy (64.2%) involved mainly two organ systems: face, including ears and eyes, and extremities, including hands and feet. Some ultrasound findings were not confirmed at autopsy (n=49). Concordance rates between sonography and autopsy findings regarding soft markers were considerably high in cases of increased nuchal fold thickness and short femur/humerus. On the other hand, fetal autopsy was of limited value as far as hyperechoic bowel and echogenic intracardiac foci are concerned. Pathologic examination provides additional information regarding many fetuses with aneuploidy, and may indicate possible directions of sonographic screening for major chromosome aberrations. However, prenatal sonography and perinatal autopsy should be considered as complementary ways of increasing our knowledge about the possible features of fetal aneuploidies.