Vertebral Abnormality without Spine–Curvature Deformity on Prenatal Ultrasonography

To evaluate the incidence, outcome, prenatal US features, and postnatal radiographic correlations of fetuses with a sonographically detected vertebral abnormality (VA) without spine-curvature deformity (SCD). Abnormal vertebrae were retrospectively identified by searching the prenatal ultrasound database at our ultrasound center over a 5-year period. Of these, 26 fetuses showing a VA without SCD were evaluated for pregnancy outcomes, sonographic data, and coexisting anomalies. Cases with neural tube defects were excluded. Medical records and postnatal radiographs of all live 16 births were reviewed. Co-existing major anomalies were suspected prenatally in 8/26 fetuses (30.8%). Sonographic abnormality were noted in vertebral body in 27/31 (87.1%) and in posterior element in 4/31 (12.9%). US features were absent (n=2) or small vertebral body echo (n=21), two separate vertebral body echoes (n=4), or smaller or lobulated posterior arch echoes (n=4). Among 16 live-born neonates, postnatal radiographs revealed vertebral abnormality in 20 (95.2%) of 21 prenatally detected VA without SCD. The abnormalities are vertebral body hypoplasia (18/19) with an incomplete sagittal cleft, asymmetric/unilateral hypoplasia, or hypoplasia with a complete sagittal cleft; or abnormalities in the spinous process (2/2). Most fetuses with prenatally detected VA without SCD revealed hypoplastic vertebrae on postnatal radiographs. In the fetus with prenatally detected VA without SCD, detailed prenatal US should be performed for possible associated abnormalities. Prenatal recognition of VA without SCD can lead to an early postnatal diagnosis of vertebral abnormality and guidance for follow-up.