Table 3.

Individual case diagnoses and referral indications for foetuses included in this study

GA	Prenatal ultrasound findings	Intracardiac injection (ToP)	Intra-uterine foetal MRI diagnosis	PMMR diagnosis	Autopsy diagnosis	Comments	Genetic testing
Concordant cases
29	ACC	KCl	ACC Left frontal cortical sulcation anomaly	ACC Left frontal cortical sulcation anomaly	ACC Left frontal cortical sulcation anomaly	All three investigations concordant (Fig. 1)	Normal microarray
22	Enlarged posterior fossa	None	DWM	DWM	DWM	All three investigations concordant	Normal microarray
Partial concordance
22	Severe VM Small cerebellum TGA Vertebral anomalies	None	VM, aqueductal stenosis RES	VM Vertebral anomalies	VACTERL Vertebral and cardiac defects RES	Both imaging concordant for VM iuMR and PMMR discordant for RES and vertebral anomalies The autopsy confirms RES and vertebral anomalies with additional cardiac defects (Fig. 2)	None
23	ACC VM Microcephaly Small cerebellum No vermis	Lignocaine	ACC Enlarged ganglionic eminences Delayed sulcation PVNH Possible tubulinopathy or dystroglycanopathy	ACC, VM	Lissencephaly spectrum Technically limited due to maceration	iuMR and PMMR concordant for ACC and VM, although iuMR demonstrated additional PVNH Brain autopsy limited by maceration, lissencephaly spectrum diagnosed, ACC, and VM not able to detect	WES–TUBB1 pathogenic mutation (tubulin gene)
22	VM Small cerebellum Microphthalmia	None	Bilateral VM Small cerebellum Microphthalmia Possible aqueduct stenosis	Bilateral VM Small cerebellum. Microphthalmia ACC	Small cerebellum Microphthalmia	Imaging concordant for VM, small cerebellum, and microphthalmia Imaging discordant for aqueduct stenosis and ACC Autopsy did not identify the ACC or aqueductal stenosis	Array CGH = gain of chromosome 2q33.1, 0.24 Mb in size Variant of unknown clinical significance
22	Partial ACC Interhemispheric cyst	None	Hypogenesis CC Persistent BPC	Hypogenesis CC	Hypogenesis CC	iuMR and PMMR concordant for hypogenesis of CC but discordant for BPC Autopsy agrees with PMMR findings	Normal microarray
31	Severe VM	Lignocaine	ACC Abnormal bilateral cortical sulcation	ACC	ACC	iuMR and PMMR concordant for ACC but not cortical malformation Autopsy confirms PMMR findings	None
19	Posterior fossa cyst	None	Hypogenesis CC DWM	ACC DWM	No consent for brain autopsy	Imaging concordant for DWM, discordant for ACC No consent for brain autopsy (Fig. 4)	None
Discordant cases
30	Bilateral VM Bilateral fixed flexion thumb deformity	None Intrapartum cephalocentesis performed	Severe VM Small dysmorphic cerebellum Aqueductal stenosis Suspected L1 CAM mutation	Large extra-axial haematomas Ventricles disrupted and collapsed	Extensive ventricular and extra-axial haematoma Collapsed ventricles Aqueductal stenosis Cerebellar heterotopias Absent medullary pyramids on histology	iuMR and PMMR discordant Autopsy identified many anomalies suspected on iuMR, and genetic testing confirmed the suspicions Intrapartum cephalocentesis hampered PMMR interpretation (Fig. 5)	Single-gene L1CAM mutation
23	Posterior fossa abnormality Small cerebellum	Lignocaine	Molar tooth malformation, absent cerebellar vermis	Normal	Absent cerebellar vermis	iuMR and PMMR discordant for absent cerebellar vermis Autopsy confirms iuMR findings (Fig. 6)	None
29	Bilateral VM	Lignocaine + KCl	MPPH syndrome	Normal	Postaxial polydactyly Non-diagnostic brain autopsy	iuMR and PMMR discordant Autopsy non-diagnostic Genetic testing confirms iuMR suspicions (Fig. 7)	WES—pathogenic PI3K mutation consistent with diagnosis of MPPH
28	VM	KCl	Unilateral intraventricular haemorrhage Periventricular venous haemorrhagic infarction	Normal	Non-diagnostic brain autopsy	iuMR and PMMR discordant Autopsy non-diagnostic	None
24	Severe VM	Lignocaine	Bilateral VM Subependymal nodular heterotopia Filamin A mutation suggested	Unilateral VM ACC	No consent for brain autopsy	iuMR and PMMR discordant for nodular heterotopia and ACC No consent for brain autopsy	FLNA mutation and maternal cranial imaging negative

ACC absent corpus callosum, BPC Blake’s pouch cyst, CC corpus callosum, CSP cavum septum pellucidum, FLNA filamin A, iuMR intra-uterine foetal MR, KCl potassium chloride, L1CAM L1 cell adhesion molecule, MPPH megalencephaly, perisylvian polymicrogyria, polydactyly and hydrocephalus, PMG polymicrogyria, PMMR perinatal postmortem MRI, RES rhombencephalosynapsis, TGA transposition of the great arteries, ToP termination of pregnancy, VACTERL vertebral, anal, cardiac, tracheoesophageal, renal and limb anomalies, VM ventriculomegaly, WES whole exome sequencing