Serial quantitative maternal nephrosonography in pregnancy.

Real time ultrasound provides a quick, safe and convenient method of examining not only the appearance but also the dimensions of the kidneys and the upper renal tract in pregnant women. Using an on-screen measuring system, the length, width and thickness of the renal and pelvicalyceal outline of both left and right kidney were measured in a non-pregnant control group, and also at regular intervals throughout pregnancy and into the puerperium in a group of healthy primigravid patients. From the results the behaviour of the total renal pelvicalyceal and renal parenchymal volumes can be followed. Furthermore they clearly illustrate the separate and independent influences on the pregnant maternal upper renal tract of urinary stasis, increased renal blood flow, and possibly cellular hypertrophy.