Prenatal Ultrasound Diagnosis of Diastematomyelia at 11–14 Week Scan

Abstract

Diastematomyelia is a rare form of congenital spinal anomaly in which the spinal cord is longitudinally split by a rigid or fibrous septum. Prenatal diagnosis of this condition has mainly been reported in the mid trimester. The authors report two cases of diastematomyelia detected at the 11-14 week scan with a brief review of literature. One case detected in the late first trimester was associated with open spina bifida, and the other detected at 12 weeks was a case of isolated diastematomyelia. Though the sonographic features of diastematomyelia are the same in the first and the second trimester, the findings are better appreciated in late first trimester as the ossification in vertebral bodies is minimal before 12 weeks of gestation. Both of the cases presented with typical sonographic features and the ultrasound findings correlated well with postnatal examination. Intracranial signs were pivotal in arriving at the diagnosis of associated open spina bifida in first trimester.