Early antenatal diagnosis of spina bifida presenting with a “step” in the posterior contour of an 8‐week embryo

We report a case of spina bifida in the upper thoracic spine with an accompanying meningocoele suspected at 8 weeks' gestation via transvaginal sonography and confirmed at 13 weeks' gestation via 3‐dimensional sonography. The fetal cranial vault and intracranial structures were normal. The only finding in the 8‐week sonogram was a subtle angulation or “step” in the posterior contour of the embryo; this may be attributed to kyphosis, which often accompanies this condition. The presence of a “step” in the fetal contour must alert the sonologist to the possibility of spina bifida. To our knowledge, this is the earliest antenatal diagnosis of spina bifida. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008