PRENATAL DIAGNOSIS OF FETAL LOWER URINARY TRACT OBSTRUCTION PRESENTING AS AN ABDOMINAL MASS IN A TWIN PREGNANCY USING THREE-DIMENSIONAL ULTRASOUND WITH "FLY THRU" TECHNOLOGY: A CASE REPORT.

We report a case of a twin pregnancy, wherein one twin presented with an abdominal cyst since 12 weeks' gestational age. Upon referral at 2 weeks' gestational age, three-dimensional ultrasound with Fly thru technology was used to aid in the identification of the etiology and nature of the mass. The arrow navigated in a cephalocaudad direction using the autopilot mode. The cystic mass had smooth inner walls. Upon approaching the most inferior portion of the mass, an opening was visualized. Upon navigation, this opening ended in a blind pouch. This was interpreted as a probable obstructed urethral os. Once megacystis was confirmed, serial vesicocentesis and urine biochemistries were used to direct the management. At 27 weeks gestational age, patient underwent preterm delivery secondary to PPROM with cord prolapse. The affected twin did not survive. Gross examination revealed the present of megacystis. The morphologically normal twin stayed at the neonatal ICU for 10 weeks and survived. [ABSTRACT FROM AUTHOR]