Seeds J W
Department of Obstetrics and Gynecology, Medical College of Virginia of Virginia Commonwealth University, Richmond 23298-0034, USA.
Semin Ultrasound CT MR. 1998 Aug;19(4):347-54. doi: 10.1016/s0887-2171(98)90092-0.
The ability to detect major malformations of the fetal urinary tract using diagnostic antenatal ultrasound is well-known. Serious obstructive or dysgenetic abnormalities are often clearly seen and their implications well-known. Less clear is the meaning of mild or minimal pyelectasis, unilateral renal agenesis, nonvisualization of the fetal bladder, and pelvic kidneys. Fetal pyelectasis rarely, if ever, is associated with a need for neonatal intervention if the diameter of the pelvis is less than 10 mm. Although mild pyelectasis occurs in up to 25% of Down syndrome fetuses, the risk of Down syndrome in the case of isolated pyelectasis in a low-risk population is less than 1 in 340. Mild pyelectasis by itself does not seem to justify invasive testing for fetal karyotype. Nonvisualization of the fetal bladder carries a high risk of renal agenesis or dysplasia, whereas unilateral renal agenesis and a fetal pelvic kidney seem to carry limited, if any, negative implications.
利用产前诊断超声检测胎儿泌尿系统主要畸形的能力是众所周知的。严重的梗阻性或发育异常通常能被清晰地看到，其影响也广为人知。然而，轻度或轻微肾盂扩张、单侧肾缺如、胎儿膀胱未显示以及盆腔肾的意义却不太明确。如果肾盂直径小于10毫米，胎儿肾盂扩张极少（如果有的话）需要新生儿干预。虽然高达25%的唐氏综合征胎儿会出现轻度肾盂扩张，但在低风险人群中，孤立性肾盂扩张情况下唐氏综合征的风险低于340分之一。单纯的轻度肾盂扩张似乎并不足以证明有必要对胎儿进行染色体核型的侵入性检测。胎儿膀胱未显示提示肾缺如或发育异常的风险很高，而单侧肾缺如和胎儿盆腔肾似乎即便有负面影响也很有限。
