P33.04: Pitfalls of prenatal ultrasound diagnosis of congenital imperforated hymen

Abstract

bladder. Severe dilatation of the left renal pelvis was noted with significant caliectasis, thinning of the renal cortex, and hydroureter. Case 2 was an 18 year old G4 P1021 who presented for assessment of fetal growth in the third trimester and was found to have a mass containing echogenic debris in the midline of the lower fetal abdomen. Follow up ultrasounds demonstrated persistence of the mass with progressive bilateral renal and ureteral dilatation. In both cases, postnatal evaluation confirmed the prenatal findings and revealed a diagnosis of imperforate hymen. Both fetuses underwent hymenostomy with subsequent resolution of the mass and improvement in hydronephrosis. Conclusion: Imperforate hymen should be considered as the etiology of renal obstructive disease in female fetuses presenting with a pelvic mass. Postnatal management and hymenostomy resulted in resolution of hydronephrosis.