Correlation of severity of prenatal hydronephrosis and severity of vesicoureteral reflux (with a review on Hydronephrosis Algorithmic approach)

Intuduction:Hydronephrosis is one of common congenital abnormality detected prenatally by ultrasonography .there is a lot s of controversy about doing post natal cystography for these patients. this study was done for determine correlation of degrees of prenatal hydronephrosis and degrees of vesicoureteral reflux(VUR).Method: Infants, whose antenatal ultrasonography (US) showed a fetal renal pelvic diameter(RPD) of 5 mm or greater were investigated. Prenatally hydronephrosis severity was defined base on 3rd trimester sonography according to RPD defined as mild(5-9mm), moderate(10-14mm) or severe(> 15mm).VUR degree were classified as mild (grade &2),moderate(grade 3),severe(grade 4&5).Postnatal urinary tract sonography and cystography were performed for all of them and according proposal algorithm, DMSA scan, DTPA scan were done if were indicated. Result:A total of 200 infants were enrolled in this study. Each kidney detected to have reflux was referred to as a renal unit (RU) and a total of 400 RUs were investigated. There were 143 (71.5%) males and 57(28.5%) females . mean of APD of prenatal hydronephrosis were 8 milimeter +/-6 (maximum =60 mm).There was a significant but weak correlation coefficient between degree of prenatal hydronephrosis and degree of VUR(p.value <0.001; R=0.22; spearman test).also , the same result was shown between degree of postnatal hydronephrosis and degree of VUR(p.value <0.001; R=0.3; spearman test). Conclusion: VUR is a relatively common finding in neonates referred for hydronephrosis. We recommend cystography for all of neonate with moderate and severe prenatal hydronephrosis and for neonate with mild prenatal hydronephrosis with other reported abnormality in kidney or bladder in sonography,increase RPD in postnatal sonography,history of urinary tract infection or sibling VUR or history of abnormal voiding.