Revised guidelines on management of antenatal hydronephrosis

Abstract

Widespread antenatal screening has resulted in increased detection of anomalies of the kidneys and urinary tract. The present guidelines update the recommendations published in 2000. Antenatal hydronephrosis (ANH) is transient and resolves by the third trimester in almost one-half cases. The presence of oligohydramnios and additional renal or extrarenal anomalies suggests significant pathology. All patients with ANH should undergo postnatal ultrasonography; the intensity of subsequent evaluation depends on anteroposterior diameter (APD) of the renal pelvis and/or Society for Fetal Urology (SFU) grading. Patients with postnatal APD exceeding 10 mm and/or SFU grade 3-4 should be screened for upper or lower urinary tract obstruction and vesicoureteric reflux (VUR). Infants with VUR should receive antibiotic prophylaxis through the first year of life, and their parents counseled regarding the risk of urinary tract infections. The management of patients with pelviureteric junction or vesicoureteric junction obstruction depends on clinical features and results of sequential ultrasonography and radionuclide renography. Surgery is considered in patients with increasing renal pelvic APD and/or an obstructed renogram with differential renal function <35-40% or its subsequent decline. Further studies are necessary to clarify the role of prenatal intervention, frequency of follow-up investigations and indications for surgery in these patients.

Renal development in the fetus and premature infant

“…However, APD is affected by multiple factors, including gestational age and maternal hydration status (and hence fetal urine output), and may worsen or improve during later development [147]. An APD of >4 mm in the second trimester or >7 mm in the third trimester are indications for follow-up [145,148–150]. Generally, dilation in the second trimester is an indication for follow-up ultrasound in the third trimester.…”

“…Cutoffs exist for predicting better renal prognosis for urinary electrolytes (sodium <100 mEq/L and calcium <8 mg/dL) and urinary concentration (osmolarity <200 mOsm/L), and markers of renal damage (β2 microglobulin <4 mg/L and protein <40 mg/dL) have been proposed, but are not without controversy [150,157]. Various measures have been attempted to predict long term outcomes of fetal hydronephrosis.…”

Postnatal radiological evaluation of antenatal hydronephrosis

“…Hidronefrozu SFU3-4 olan olgularda, bilateral hidronefrozu olan olgularda, üreter dilatasyonu görülen olgularda, antenatal hidronefrozu olup, idrar yolu enfeksiyonu geçiren olgularda, mesanede duvar kalın-laşması ve dilatasyon gibi alt üriner sistem obstrüksi-yonu düşünülen olgularda MSUG yapılmalıdır (3) .…”

“…Antenatal hidronefroz, prenatal ultrasonda (1) %0.6-5.4 ile en sık saptanan anomalidir (2,3) . Farklı etiyolojiler sonucu gelişebilir (Tablo 1).…”

“…Farklı etiyolojiler sonucu gelişebilir (Tablo 1). Etiyolojinin tipine de bağlı olarak %4.1-15.4 arasında ürolojik girişim gerekebilir (3) . Sıklıkla 3. trimesterda ya da doğumun hemen sonrasında kaybolan geçici veya fonksiyonel olarak adlandırılan tipte hidronefroz gözlenir (4,5) .…”