Fetal intervention for myelomeningocele: effect on postnatal bladder function

Myelomeningocele is the most common congenital malformation of the central nervous system noted on prenatal ultrasound. Due to its significant postnatal sequelae, treatment in utero could potentially have a profound impact on the newborn. Others have reported fetal surgical techniques for in utero repair of myelomeningocele and its potential benefits on motor and neurological function. We report our urodynamic findings in the newborn after in utero repair of spina bifida in an effort to characterize postnatal bladder function.

A retrospective review of the fetal surgery database at University of California San Francisco was performed identifying patients with a diagnosis of myelomeningocele. Prenatal surgical repair of myelomeningocele was considered if a normal karyotype was present, no other significant congenital anomalies were evident and gestational age was less than 24 weeks. The spinal defects were in the lumbar or lumbosacral region. All surgery was performed before 24 weeks of gestations.

Fetal surgery to correct myelomeningocele was performed in 6 patients. All patients were born premature at 32 weeks of gestation or less. Videourodynamics performed at age 1 month in 4 patients indicated decreased bladder capacity for weight, increased detrusor storage pressures and significant post-void residual. Hydronephrosis was demonstrated in 4 patients on renal/bladder ultrasound, and moderate vesicoureteral reflux was seen in 3.

Patients with spinal bifida treated in utero appear to have the same changes in urodynamic parameters and anatomical abnormalities in the urinary tract as other children with spinal defects who have undergone standard postnatal care. In utero treatment of spinal bifida may expose the newborn to the effects of prematurity. The long-term effects on bladder function in the fetus after in utero repair of myelomeningocele remain unknown. A randomized controlled trial is necessary to evaluate long-term bladder function as well as other outcome variables in this experimental approach to patients with myelomeningocele.