Introduction: Distended fetal bladder(DFB) is observed in less than 1% of fetal ultrasounds but it can be the presenting sign of serious CAKUT (congenital anomalies of kidneys and urinary tract) with consequent risk for ESRD (end stage renal disease).
Methods: Files of all the women referred to Dana-Dwek Pediatric Nephrology Clinic consultation for DFB during 2010-2017 and for whom postnatal follow-up was available were searched.
Results: 37 fetuses with suspected DFB: 34/37(92%)male were diagnosed at median 25GW (gestational week)- 17/37(46%)≤ 22 GW. First fetal sonographic finding at presentation was: isolated unilateral/bilateral hydronephrosis±ureter- 17/37(46%), isolated DFB- 9/37(24%). Oligohydramnion was found in 3/37(8%) and extrarenal anomalies were suspected in 4/37(11%). Amniocentesis (including CMA in 40%) performed in 23/37 was normal. TOP (termination of pregnancy) was chosen by parents in 4/37(11%). Delivery was at term in all the others, 73%- normal birth weight - AGA(Appropriate for gestational age). At 48hours age sonographic complete bladder emptying -19/33(58%) but hyperechogenic kidney parenchyma- 8/33(24%) and elevated serum creatinine- 6/31(19%) were found. Neonatal surgical interventions were needed in 3/33(9%): 2/33- PUV fulguration, 1/33- vesicostomy, 1/33- spontaneous PUV ablation during bladder catheterization. Final diagnoses were : VUR(vesicoureteral reflux)- 12/33(36%), 3/33(9%)-PUV(posterior urethral valves), dysplastic kidneys in 5/6 of MAG or DMSA renoscans performed. UTI (urinary tract infections) occurred during follow-up in 3/33(9%). 7/33(21%) newborns had systemic anomalies:1- ASD(autistic spectrum disorder), 4-genital,2-multiple.
Conclusions: More than half DFB will empty after birth. The most common etiology of DFB is VUR. Associated renal damage and significant systemic disorders might exist in up to a quarter of cases.
