孕妇,21岁,孕18周,孕1产0。既往身体健康,无遗传性疾病。超声显示:单胎,头位,双顶径42mm,头围150 mm,腹围126 mm,股骨长27mm,胎儿颅内结构、脊柱排列、胸腔器官、四肢、胎盘及羊水均未见异常。胎儿腹腔器官胃泡、肝脏、胆囊及肠管未见异常。胎儿左肾大小约37 mm×25mm,肾盂扩张10mm,肾盏中度扩张,输尿管扩张 Pregnant women, 21 years old, 18 weeks pregnant, pregnant 1 produce 0. Past physical health, no genetic disease. Ultrasound showed no abnormalities in single fetus, head position, biparietal diameter 42 mm, head circumference 150 mm, abdominal circumference 126 mm, femur length 27 mm, fetal intracranial structure, spinal alignment, thoracic organs, limbs, placenta and amniotic fluid. Abdominal organs of the fetus stomach bubble, liver, gallbladder and bowel no abnormalities. Fetal left kidney size of about 37 mm × 25mm, pyelonephrosis 10mm, moderate expansion of calyx, ureteral dilatation