Diagnosis of Fetal Multicystic Dysplastic Kidney in the First Trimester of Pregnancy by 2-D and 3-D Ultrasonography

Abstract

A 35-year-old primigravida woman underwent first-trimester ultrasound examination for screening of fetal abnormality at 13 weeks. The nuchal translucency was within normal limits (1.9 mm), and the combined ultrasound and biochemistry test returned a low risk of fetal aneuploidy. However, fetal anatomical survey showed several cystic spaces scattered throughout the left kidney with preservation of the reniform shape, suggestive of a unilateral multicystic dysplastic kidney ( Figure 1 ). The contralateral right kidney was normal. Targeted ultrasound of the fetal renal tract at 14 5 weeks continued to demonstrate an enlarged left kidney (length 22 mm) with multiple cystic spaces scattered throughout (ranging in size from 2–8 mm), while the right kidney appeared normal ( Figure 2 ). There was no dilation of the renal pelvis dilatation, and the rest of the genitourinary system, including bladder, liquor volume, and genitalia, appeared unremarkable. Second-trimester 3-D ultrasound in the multiplanar and rendering modes at 20 weeks confirmed a grossly enlarged left fetal kidney that contained multiple cysts of varying sizes (5–22 mm) ( Figure 3 ). In addition, moderate left ureteric dilation was also noted. The right kidney remained normal, and the rest of the detailed morphology assessment did not demonstrate any additional abnormalities in the female fetus. Subsequent review at 30 weeks showed the left fetal kidney to be persistently markedly enlarged, containing multiple non-communicating cysts of variable sizes throughout. The renal parenchyma was also echogenic, but there was no obvious evidence of dilated ureters. Antenatal pediatric urology review was organized, and the baby was delivered at 38 completed weeks, with postnatal ultrasound and MAG3 scan confirming a nonfunctioning multicystic dysplastic left kidney but normal functioning right kidney.