Editing CUA: Antenatal hydronephrosis (2017) (section)

== Follow-up protocols ==

* '''Based on severity of hydronephrosis'''
** '''See [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5905549/figure/f1-cuaj-4-85/ Figure 1] from Original Guideline'''

=== High-grade hydronephrosis (SFU Grades 3 and 4) or APD >15 mm on 3rd Trimester Ultrasound ===
* '''<span style="color:#ff0000">Initial post-natal RBUS'''
** '''<span style="color:#ff0000">Should be done as soon as feasible after day 2 of life</span>''' (most centres recommend '''<span style="color:#ff0000">within 2 weeks of life</span>''') as this represents the cohort most likely to require surgery and to experience UTI.
** '''<span style="color:#ff0000">If the postnatal US reveals persistent high-grade hydronephrosis, these cases should be referred to a pediatric urologist for immediate consultation.'''
*** Bilateral HGHN requires more urgent consultation.
* '''<span style="color:#ff0000">Additional investigations'''
** '''<span style="color:#ff0000">Patients should have a VCUG'''
*** '''<span style="color:#ff0000">MAG3 renal scan should be done if the VCUG is negative for VUR'''
* '''<span style="color:#ff0000">These cases are most likely to benefit from CAP'''
* '''<span style="color:#ff0000">In the absence of any pathology requiring immediate intervention, repeat US and MAG3 should be performed within 3 months,</span>''' although a repeat MAG3 is optional if the first exam is normal. '''If improvement is not seen, close follow-up should continue to at least 18 months of age,''' by which time most childhood UPJO becomes apparent.

* For cases with antenatal APD 10‒15 mm, the SFU grading is suggested to clarify which follow-up protocol should be used

=== Low-grade hydronephrosis (SFU Grade 1 and 2) or APD <10 mm on 3rd Trimester Ultrasound ===
* '''<span style="color:#ff0000">Initial post-natal RBUS'''
** Timing open to debate; '''<span style="color:#ff0000">most physicians will obtain an US within the first months of life and a follow-up can be obtained 6 months later.'''
*** In the absence of deterioration, follow-up US can then be performed on an annual basis.
* '''<span style="color:#ff0000">Additional investigations'''
** '''<span style="color:#ff0000">VCUG and MAG3 are not required'''
* '''<span style="color:#ff0000">CAP is unnecessary'''
* '''The majority of such cases improve by age 2'''. Since the majority of congenital UPJO progresses to pyeloplasty by 18 months of age, '''continue follow-up to at least until age 2.'''
** There is controversy on the need for follow-up beyond 2 years of age in patients who have persistent LGHN.

=== SFU Grade 0 ===
* '''Up to 50% of ANH can resolve at birth and is referred to as SFU Grade 0 HN.'''
* '''<span style="color:#ff0000">SFU guidelines recommend a repeat US within the first month of life.'''
** Many centres will discharge the patient after a normal post-natal US, since the majority of late or recurrent HN are symptomatic and can be counselled as such.
**"it appears contradictory to follow up a documented LGHN within six months, whereas a normal US is followed up within one month."
*'''<span style="color:#ff0000">[In patients with a history of mild to moderate fetal hydronephrosis and a normal post-partum ultrasound (obtained at 1-2 months), additional evaluations are unnecessary.]'''
* '''<span style="color:#ff0000">[In patients with a history of moderate to severe fetal hydronephrosis and a normal post-partum ultrasound, additional evaluations are necessary.]'''
** '''The presence of ureteral dilation on the pre-natal ultrasound has been found to be associated with a significant increased risk for neonatal UTIs and high-grade vesicoureteral reflux despite a normal post-partum renal ultrasound.'''
** A neonatal VCUG is recommended if ureteral dilation is found on the fetal ultrasound.