* Fetal medicine unit, Cairo University, Egypt;

** Department of Obstetrics & Gynecology; Cairo University, Egypt;

*** Radiology Department, Kasr Alainy Teaching Hospitals, Cairo University, Egypt.

Congenital anomalies of the spinal cord can lead to bladder dysfunction and neurological deficits in lower limbs and may affect the upper urinary tract due to vesicoureteric reflux or increased intra vesical pressure or detrusor sphincter dyssynergia ¹. Incomplete bladder emptying is a complaint not only in children with open spina bifida but also those with closed spina bifida and may enhance the risk of urinary tract infections¹. Galloway et al. introduced an objective score system (hostility score) which uses certain urodynamic features of bladder dysfunction to quantify risk of upper urinary tract deterioration in cases of myelodysplasia ². Interestingly, hydronephrosis occurred at a late stage in some of their cases².Upper urinary tract deterioration can occur in childhood as a result of the presence of external urethral sphincter dyssynergy at birth in fetuses with myelodysplasia who may present with hydronephrosis and reflux ³ . Renal pelvic dilatation in children with myelodysplasia is an indication for urodynamic study which may be carried out even before an evidence of pyelectasis³. Pinette et al. have reported a fetus with open lumbosacral spine bifida with consequent rupture of his neurogenic bladder that occurred at the 34th week of gestation and this spontaneous decompression had a protective effect on the fetal kidneys in their case ⁴. It is important to bear in mind that once an enlarged fetal bladder is encountered and after exclusion of transient physiological dilatation; a careful examination of the fetal spine should be performed. The presence of hydronephrosis in association with enlarged bladder is indicative of a substantial malformation and its absence is likely indicative of normal variation in size ⁴.

A 28 year old G4P3 woman attended to our fetal medicine unit at 39 weeks of gestation. There was no consanguinity and her history was unremarkable. Our ultrasound examination revealed the following:

- Microcephaly with slanting forehead.

- Huge encephalocele herniating through a bony defect in the occipital bone.

- Large thoracolumbar open spine bifida.

- Mild dilatation of renal pelvi calyceal system on both sides with normal echogenicity of renal parenchyma and normal cortico medullary differentiation.

- Persistently dilated bladder throughout the whole scan time.

- Unremarkable rest of anomaly scan.

Based on our ultrasound examination; our diagnosis was occipital encephalocele associated with open thoracolumbar spina bifida with neurogenic bladder secondary to the neural tube defect. Neurogenic bladder resulted in deterioration of the upper urinary tract manifested by mild hydronephrosis yet, with preserved normal echogenicity of the renal parenchyma and normal corticomedullary differentiation without any cortical cyst formation. It is well-established in the pediatric literature that neurogenic bladder develop in a significant percent of children with open and even closed spinal dysraphism. We recommend a careful examination of the spine once a persistent enlarged bladder is noted during an ultrasound scan as some spinal lesions may be subtle and require high level of suspicion to be diagnosed. 

Image 1, videos 1 and 2: show the huge occipital encephalocele with herniated brain matter and covering meninges through the occipital bone defect.