Demographic and clinical data

Fetus No.	Mother’s Age (y)	Gestational Age (wks)	Clinical or Prenatal Problem at US	Prenatal Brain T2-Weighted SS FSE Findings	Postnatal Brain MR or US Findings
1	34	30	Intestinal occlusion	Normal	Normal (US)
2	32	32	Mega-cisterna magna	Mega-cisterna magna	Posterior fossa arachnoid cyst; normal cerebellum vermis, and cerebral hemispheres (MR)
3	35	24	TTTS, larger (receiver) twin studied	Normal	Normal (MR)
4	33	28	TTTS, larger (receiver) twin studied	Normal	Normal (MR)
5	23	29	Mega-cisterna magna	Mega-cisterna magna	Mega-cisterna magna; normal cerebellum, vermis, and cerebral hemispheres (MR)
6	27	34	Neck mass	Normal	Normal (US) (neck cystic hygroma at surgery)
7	35	24	Lumbar hemivertebrae	Normal	Not available (pregnancy terminated; skeletal malformations, no meningocele, and normal brain at autopsy; normal chromosomic map).
8	28	25	Facial anomalies	Normal	Normal (US) (facial anomalies not confirmed)
9	37	23	Two previous pregnancies with corpus callosum agenesis	Normal	Normal (US)
10	31	29	Intestinal occlusion	Normal	Normal (US)
11	37	22	Pulmonary adenoid cystic malformation	Normal	Normal (US)
12	29	32	Amnionic bands and oligohydramnios	Normal	Normal (US)
13	34	25	Diaphragmatic herniation	Normal	Normal (MR)
14	32	35	Focal hepatic lesion	Normal	Normal (US)
15	37	22	One previous pregnancy with corpus callosum agenesis	Normal	Normal (US)

Note.—TTTS indicates twin-to-twin transfusion syndrome; SS FSE, single-shot fast spin echo.