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Postnatal management of fetal hydronephrosis

Laurence S Baskin, MD, FAAP
Section Editor
Duncan Wilcox, MD
Deputy Editor
Melanie S Kim, MD


Fetal hydronephrosis (dilation of the renal pelvis) is a common, readily diagnosed finding on antenatal ultrasound examination, which may be a transient benign condition or be associated with significant congenital anomalies of the kidney and urinary tract (CAKUT). The goals of postnatal management of infants with fetal hydronephrosis is to identify those with clinically significant CAKUT while avoiding unnecessary testing in patients with physiologic or clinically insignificant hydronephrosis. In addition, early identification of infants with significant disease allows initiation of interventional therapy that may minimize adverse effects of CAKUT.

Postnatal management of infants diagnosed with fetal hydronephrosis is reviewed here. The definition, etiology, and prenatal issues of fetal hydronephrosis and specific urologic conditions that may present as fetal hydronephrosis are discussed separately. (See "Overview of fetal hydronephrosis" and "Congenital ureteropelvic junction obstruction" and "Primary megaureter in infants and children" and "Ectopic ureter".)


In most cases, renal pelvic dilation diagnosed in utero is a transient, physiologic state, however, congenital anomalies of the kidney and urinary tract (CAKUT) can present with fetal hydronephrosis due to urinary tract obstruction and vesicoureteral reflux (VUR). These conditions may be associated with impaired normal renal development and/or cause renal injury. Nevertheless, the majority of cases of fetal hydronephrosis are not clinically significant, and therefore excessive concern may lead to unnecessary testing of the newborn infant and anxiety for parents and health care providers.

The goals of postnatal management of infants with fetal hydronephrosis are to identify patients with significant CAKUT while avoiding unnecessary testing in patients with physiologic or clinically insignificant hydronephrosis. Evaluation includes physical examination and the use of imaging studies to detect abnormalities that will require postnatal intervention.

There is not a single test or finding that accurately differentiates infants with significant disease from those who are normal or have insignificant findings. In our practice, we use an approach based upon the presence of predicative factors (bilateral involvement and severity of persistent fetal hydronephrosis) for postnatal management that limits unnecessary testing and minimizes parental distress [1,2]. (See 'Approach' below and "Overview of fetal hydronephrosis", section on 'Congenital anomalies of the kidney and urinary tract (CAKUT)'.)

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Literature review current through: Oct 2017. | This topic last updated: Oct 02, 2017.
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