Pop‐off mechanisms in fetal megacystis: extravasation, umbilical cord cyst, ureterocele and megaureter

• DOI: 10.1002/uog.29200
• Publication Date: 2025-03-11T17:18:00Z
• Authors: L. A. M. Brinkman; L. K. Duin; P. N. Adama van S...; T. E. Cohen‐Overbeek; E. Pajkrt; M. N. Bekker; C. Willekes; E. J. T. Verweij; C. Bilardo; F. Fontanella
• Keywords: Megaureter; Ureterocele; Renal agenesis; Urinoma

To analyze comprehensively the incidence, antenatal ultrasound characteristics and prognostic implications of pop-off mechanisms fetal urinary system in pregnancies with suspected megacystis. This was a retrospective multicenter study megacystis conducted across all academic hospitals The Netherlands. Three were identified: presence an umbilical cord cyst (UCC), extravasation urine into intraperitoneal space (ascites) or perirenal subcapsular (urinoma), megaureter/ureterocele. Cases that exhibited two different mechanisms, underwent vesicoamniotic shunt placement had unclear information regarding excluded. We compared outcomes among UCC, those extravasation, megaureter/ureterocele without mechanism. Logistic regression analysis used to evaluate association postnatal outcomes. Among 543 fetuses megacystis, 76% no mechanism, 7% presented UCC only, 9% only 1% mechanisms. Following exclusions, 511 cases included analysis. identification (n = 39) associated early-onset (odds ratio (OR), 4.2 (95% CI, 1.9-9.1); P < 0.001), severe (OR 2.3 1.1-5.0); 0.033), normal amniotic fluid index (AFI) (OR, 3.3 1.3-8.2); 0.011) additional anomaly 1.7-6.4); thus highest prevalence complex diagnosis (66%), primarily represented by anorectal malformation. Extravasation 42) 2.4 1.1-5.4); 0.030), abnormal AFI 2.8 1.2-6.8); 0.022), keyhole sign 2.5 1.1-5.8); 0.033) 2.1 1.1-4.1); 0.026). Megaureter/ureterocele 36) late-onset 4.0 1.6-9.7); 0.003), thickened bladder wall during pregnancy 6.6 1.9-23.1); 0.003) lowest (22%). Intrauterine demise most prevalent (15%), while termination non-survivors common (50% 17%, respectively). majority still alive follow-up (72%) odds survival for this group 2.7 1.3-5.7); 0.010). Antenatal may alleviate high intraluminal pressure within tract. Each mechanism leads clinical picture outcome, which explain partially heterogeneity Therefore, understanding these their could guide counseling management © 2025 Author(s). Ultrasound Obstetrics & Gynecology published John Wiley Sons Ltd on behalf International Society Gynecology.