Posterior Urethral Valves (PUV) – from prenatal ultrasound features to postnatal outcomes

• Applicant: Dr. Franziska Juliane Richter
• Subject Area: Reproductive Medicine, Urology
• Term: from 2023 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 518327802

Posterior urethral valves (PUV) are the most common cause of lower urinary tract obstruction (LUTO) in males with 1-2/10000 affected births. Prenatal ultrasound features typical of PUV include megacystis, bilateral hydroureteronephrosis, keyhole sign and oligohydramnios. Despite an increased predictive accuracy of combining these ultrasound features, prenatal detection is challenging and not 100% reliable. If the findings are suggestive of LUTO, parents should be told that LUTOs are life-long chronic conditions which may have significant morbidity and mortality rates in the prenatal and neonatal periods. In case of severe findings (anhydramnios), fetal interventions such as vesicoamniotic shunting (VAS) may be offered in an attempt to prevent pulmonary issues postnatally. Most boys with PUV will develop some degree of bladder dysfunction and it is estimated that one-third will develop end-stage renal disease (ESRD) and requires eventual dialysis or renal transplant. Hence, delivery at a high-risk center for early and multidisciplinary care is essential. Prompt postnatal ultrasound, bladder decompression, continuous antibiotic prophylaxis initiation and consequent monitoring of urine output are key points of initial management. After stabilization and VCUG-based confirmation of diagnosis, further treatments like valve ablation or lower/higher diversion can be considered, dependent on the patient’s condition and individual preferences. Although, there exist recently published guidelines and treatment recommendations based on expert consensus and guided by the available literature, the supporting level of evidence is limited and management between providers and institutions varies widely. Given the varied prenatal presentations of PUV based on ultrasound features, the responsibility of providers to give informed and thorough prenatal consultations and the consequences of a possible missed diagnosis, it is important to understand how specific prenatal ultrasound features translate into outcomes for children with PUV. The aim of this project is to partner with a high-risk tertiary fetal center (Mount Sinai Hospital, Toronto, Canada) to match pregnant females carrying fetuses with suspected LUTO to children with LUTO being followed at SickKids to understand how the prenatal ultrasound findings relate to the known postnatal outcomes. A secondary objective will be to review the prenatal ultrasound features of women who terminated their pregnancies due to a possible LUTO diagnosis as well as fetuses with autopsies, and match those to women with similar findings but continued their pregnancies. This project allows us the opportunity to improve prenatal counseling for these families as we will be able to tell them “what if” they continue the pregnancy or decide on potential treatment (surveillance vs. prenatal intervention) given specific ultrasound features with respect to early and long term outcomes (e.g. ESRD) in their child.

• DFG Programme: WBP Fellowship
• International Connection: Canada
• Host: Professor Dr. Armando J. Lorenzo