Purpose of Review <p>Antenatal hydronephrosis is one of the most common anomalies diagnosed prenatally and is not always clinically significant. The primary clinical challenge lies in early risk stratification, which involves identifying infants at risk of progression and intervening to preserve renal function while minimizing unnecessary imaging and overtreatment. This review presents an evidence-based framework for evaluating and managing antenatal hydronephrosis postnatally.</p> Recent Findings <p>The Urinary Tract Dilation (UTD) classification system is now the emerging standard for risk stratification. While voiding cystourethrography (VCUG) remains indicated in selected cases, recent guidelines favor a more selective approach to reduce radiation and avoid unnecessary interventions. Novel studies highlight the promise of urinary biomarkers and artificial intelligence (AI) tools to refine prognosis and guide surgical triage, though these remain investigational.</p> Summary <p>Most cases of low-grade hydronephrosis resolve spontaneously and are best managed conservatively. However, high-risk conditions, including posterior urethral valves (PUV), bilateral anomalies, or recurrent febrile urinary tract infections (UTIs), warrant structured surveillance, prophylactic antibiotics in select cases, and early surgical referral when appropriate. Longitudinal monitoring is essential even after apparent resolution, particularly in infants at risk for progressive nephron loss, hypertension, or proteinuria. Clinicians should also recognize and address the psychosocial burden on families. Future progress depends on integrating clinical, imaging, and biomarker data into predictive models that enable personalized and cost-effective care.</p>