A case of in utero spondylothoracic dysostoses is diagnosed during a routine third trimester ultrasound scan in a low-risk patient. Ultrasound showed spine deformation, hemivertebrae and crab-like ribs. The newborn had no other associated anomalies except inguinal hernia, and karyotype was normal. Bidimensional and 3-4D ultrasound imaging as well as radiograph of the fetus and photos of the newborn are presented and discussed. Sporadic cases are difficult to diagnose and classify, as they are probably due to genetic heterogenicity. Sporadic cases of hemivertebrae are rare and not always lethal. Fetal ultrasound scan findings can help predict prognosis, enabling the parents' informed decision making.