Spina bifida; Cleft spine
Definition of Myelomeningocele
Myelomeningocele is a birth defect in which the backbone and spinal canal do not close before birth. The condition is a type of spina bifida.
Causes, incidence, and risk factors
Normally, during the first month of a pregnancy, the two sides of the spine (or backbone) join together to cover the spinal cord, spinal nerves and meninges (the tissues covering the spinal cord). Spina bifida refers to any birth defect involving incomplete closure of the spine.
A newborn may have a sac sticking out of the mid to lower back. The doctor cannot see through the sac when shining a light behind it. Symptoms include:
Signs and tests
Prenatal screening can help diagnose this condition. During the second trimester, pregnant women can have a blood test called the quadruple screen. This test screens for myelomeningocele, Down syndrome, and other congenital diseases in the baby. Most women carrying a baby with spina bifida will have a higher-than-normal levels of a protein called maternal alpha fetoprotein (AFP).
Genetic counseling may be recommended. In some cases where severe defect is detected early in the pregnancy, a therapeutic abortion may be considered.
A myelomeningocele can usually be surgically corrected. With treatment, length of life is not severely affected. Neurological damage is often irreversible.
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 11/2/2009