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Evaluation and management of isolated renal pelviectasis diagnosed on second trimester ultrasound

Diagnosis/definition: The most commonly used criteria for diagnosis of pelviectasis are an AP measurement of > 4 mm in the second trimester and/or >7 mm in the third trimester.
Epidemiology/Incidence: Fetal pelviectasis is a common finding on mid-trimester ultrasound, occurring in 0.5-4.5% of fetuses.
Risk factors/associations: While usually isolated, in some cases, pelviectasis can occur due to true renal pathology and/or be associated with other fetal anomalies, including Down syndrome.

  • Screening/Work-up: Evaluation includes a detailed anatomic survey by an experienced provider and assessment of risk factors for aneuploidy, including maternal age, results of other screening or diagnostic tests, and family history.
  • Prenatal care: Fetuses with pelviectasis >4 mm in the second trimester should have a follow up evaluation at approximately 32 weeks gestation with the primary goal of determining a need for postnatal evaluation.

Post-partum: Neonatal imaging, when needed, should generally be deferred until after 7 days of age.

Last Reaffirmed: Feb 1, 2013