Myelomeningocele (myelodysplasia or spina bifida) refers to a wide range of neural tube defects affecting the spine and spinal cord. These defects result from maldevelopment of the neuropore and the adjacent mesodermal and ectodermal structures during embryogenesis. Myelomeningocele can be classified as either open or closed according to the presence or absence of exposed neural tissue. Myelomeningocele occurs early during embryogenesis, resulting in a certain number of fetuses being spontaneously aborted1. In addition, advances in prenatal screening have led to an increase in the number of therapeutic abortions1-3. Because of the unknown numbers of spontaneous and therapeutic abortions, establishing the true incidence of myelomeningocele is very difficult. Epidemiological studies have revealed that the prevalence of myelomeningocele varies, depending on such factors as ethnicity, race, geography, and temporal trends1. It is estimated that over 4500 pregnancies per year are affected by this malformation in the European Union4, and approximately 3000 pregnancies per year are affected in the United States5. In 2005, the rate of myelomeningocele was 18.0 per 100,000 births in the United States6.