990 Postnatal Follow-Up of Antenatal Hydronephrosis

Antenatal hydronephrosis is diagnosed in 1% to 5% of all pregnancies; however, the antenatal and postnatal management of hydronephrosis varies widely. The main point of postnatal management is the identification of the minority of patients whose renal function is at risk. Postnatal follow-up was considered successfully established when the patient with unresolved ANH has been evaluated in our pediatric nephrology service and had two normal postnatal USs that documented resolution of ANH. Screening of approximately 13125 ultrasound (US) reports identified 210 (1.6%) fetuses with ANH. 176 infants were included in follow-up. 30 (14%) were lost to follow-up. 4 with renal malformation were excluded. 176 infants were diagnosed with mild 105 (59.7%), moderate 59 (33.5%) and severe 12 (6.8%) hydronephrosis. 76.1% were males; unilateral and bilateral hydronephrosis were diagnosed in 116 (66%) and 60 (34%) cases, respectively; the rate of left hydronephrosis was 70.5%. Ultrasound evaluation of hydronephrosis was performed with morpho-dynamic technique. This method assesses the maximum dilation after filling bladder and then after voiding. Thus a functional or organic dilation can be detected. At 3month Us control,53% of mild-group recover spontaneously. Voiding cystourethrography was performed in 25% of mild-group. No ureteropelvic junction or obstruction and vesicoureteric reflux were detect. At the end of follow-up (24month) mild/moderate groups recover. Urinary tract malformations were found only in severe hydronephrosis while in mild/moderate group only “excretory system dysmaturity” was evidenced. Our trial showed a decreased use of invasive diagnostic procedure.