The Diagnostic Features of Spina Bifida: The Role of Ultrasound

Abstract

Myelomeningocele (MMC) is one of the most devastating, nonlethal congenital anomalies worldwide. The live birth prevalence of MMC changed dramatically in the 1980s with the introduction of maternal serum screening and the widespread use of prenatal ultrasound imaging. The high-resolution ultrasound affordable today with state-of-the-art equipment allows us to make a very accurate diagnosis of MMC, including details related to the entire fetal central nervous system. Ultrasound can accurately localize the site of the osseous and soft tissue defects. Congenital spinal defects can be characterized definitively as open or closed, which are treated very differently with in utero repair, which is done in some cases, compared to only conservative follow-up with postnatal therapy for occult defects. Additional findings of kyphosis, scoliosis and anomalous vertebrate and associated conditions such as cervical syrinx can be identified. The state of the intracranial structures, including the presence or absence of ventriculomegaly and hindbrain herniation, as well as unexpected complications such as intracranial hemorrhage can be diagnosed. The severity of neurological compromise in some fetuses can be estimated by detailed examination of the lower extremities. As well as searching for talipes, we also now routinely characterize flexion and extension motions at the hip, knee and ankle joints. The information provided by ultrasound plays a crucial role, now more than ever, in patient counseling and pregnancy management. This article emphasizes how we utilize ultrasound in the evaluation of patients with suspected MMC at the Center for Fetal Diagnosis and Treatment at the Children's Hospital of Philadelphia.