Three-dimensional ultrasound in prenatal diagnosis of encephalocele: Report of a case

A 28-year-old primigravida was referred to our outpatient department at 30 weeks' gestation. Two-dimensional (2-D) abdominal ultrasound showed a juxtacranial mass located in the fetal occipital region. The mass could not be satisfactorily evaluated because of its close association with the surrounding tissue. An encephalocele was suspected and three-dimensional (3- D) ultrasound was performed. After processing the 3-D ultrasound images, a bone defect measuring 18 mm in diameter was identified and the volume ratio of the mass/brain tissue (23.4%) obtained. Encephalocele was diagnosed. The patient was informed of the poor prognosis and, after counseling, the pregnancy was terminated at 31 weeks' gestation. Three-dimensional ultrasound provides an alternative option in the prenatal diagnosis of difficult conditions not easily identified by traditional ultrasound. Postmortem analysis showed an encephalocele measuring 6.5 x 6.0 cm in the occipital region.