Predict pregnancy outcomes of prenatal megaureter by prenatal ultrasonography

Abstract

Purpose of Investigation: To evaluate clinical and ultrasonographic characteristics of prenatally diagnosed megaureter to predict postnatal outcomes. Materials and Methods: This retrospective study was conducted on eight fetuses with megaureter which was defined 5 mm or more in diameter of distal ureter in prenatal ultrasonography between March 2008 and September 2015. The authors investigated gestational age at diagnosis and delivery, Z-score for birth weight, progression of ureter diameter, and grade of hydronephrosis between prenatal and postnatal period, neonatal outcomes. Results: Six cases had unilateral megaureter and two cases had both. Of a total of ten renal units (RU), six RU were on the left side. Median gestational age at diagnosis of megaureter was 32.4 weeks and Z-score for birth weight was -0.88. The last mean ureter dilatation before delivery was 13.3 mm. The median postnatal ureter diameter was 9.5 mm. Number of grade II megaureter was five at the time of diagnosis. All were Group III after birth. The causes of megaureter were classified as follows: four RU of obstructed type at the vesicoureteric junction, one RU of refluxing type, two RU of mixed type, two RU in secondary type, and one RU resolved spontaneously after delivery. Three cases were conservatively managed, while five cases required invasive interventions. Megaureters were managed invasively had a tendency to be diagnosed at an earlier gestational age, in males, bilateral megaureters, combined anomalies, and lower Z-score for birthweight. Conclusion: On prenatal ultrasound, megaureter diagnosed at earlier gestational age, male sex, bilateral megaureters, and lower Z-score for birthweight may more likely require invasive management.