Abstract
Background/Objectives: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disorder; it is typically diagnosed in adulthood, but occasionally presents antenatally as very-early onset ADPKD. Despite advances in prenatal ultrasonography, knowledge regarding the postnatal course of fetal ADPKD remains limited, restricting reliable prognostic assessment and prenatal counselling. This study aimed to evaluate the prenatal sonographic features of fetal ADPKD and their correlation with postnatal outcomes. Materials and Methods: We retrospectively reviewed 20 cases of prenatally suspected ADPKD diagnosed at a single tertiary referral center between 2006 and 2024. Prenatal ultrasonographic findings including renal size, cortical echogenicity, corticomedullary differentiation (CMD), and cortical cysts were analyzed and correlated with postnatal clinical and genetic outcomes. Postnatal follow-up data, including renal function and progression to chronic kidney disease (CKD), were collected with a median follow-up of 93.6 months. Results: The most consistent prenatal ultrasonographic findings were increased cortical echogenicity (85%), increased CMD (75%), and renal enlargement (35%), with cortical cysts detected in 45% of cases. Amniotic fluid volume was preserved in most cases (80%). Postnatally, most infants maintained normal or near-normal renal function, although two progressed to CKD. Both CKD cases demonstrated absent CMD on prenatal imaging. Sonographic features resembling autosomal recessive polycystic kidney disease (ARPKD) were associated with adverse outcomes. Although CMD severity showed no correlation with short-term neonatal outcomes, loss of CMD may still serve as a potential early indicator of long-term renal dysfunction. Conclusions: Fetal ADPKD was associated with heterogeneous postnatal outcomes. Loss of CMD and ARPKD-like sonographic appearances may be associated with adverse prognosis, whereas most infants maintained preserved renal function. Early recognition of ADPKD is crucial for accurate counselling, appropriate perinatal management, and long-term surveillance.