URINARY TRACT INFECTIONS.. . . . . . . . . . . . . . . . . . .. 1026 NEPHROLITHIASIS.. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1030 PREGNANCY AFTER RENAL TRANSPLANTATION .... 1030 POLYCYSTIC KIDNEY DISEASE . . . . . . . . . . . . . . . . . .. 1031
GLOMERULAR DISEASES ....i......i....i...0..o...i.0...... 1032
CHRONIC KIDNEY DISEASE.. . . . . . . . . . . . . . . . . . . . .. 1034 ACUTE KIDNEY INJURY.. . . . . . . . . . . . . . . . . . . . . . . .. 1036
LOWER GENITAL TRACT LESIONS .0...0.i.......i......i.. 1037
In rare instances in patients suiringfrom pyelitis, the preg nant uterus may so compress the ureter as to cause a dam ming back of the purulent discharge, and thus give rise to a pyelonephritis.
-]. Whitridge Williams (1903)
Renal and urinary tract disorders are frequently encountered in pregnancy. Some precede pregnancy-one example being nephrolithiasis. In some women, pregnancy-induced changes may predispose to development or worsening of urinary tract disorders-an example is the markedly increased risk for pyelonephritis, described above by Williams. Finally, some renal pathology is unique to pregnancy, such as preeclampsia. With good prenatal care, however, most women with these disorders will likely have no long-term sequelae.
Significant changes in both structure and function within the urinary tract during normal pregnancy are discussed in Chapter 4 (p. 65). he kidneys become larger, and dilatation of the right renal calyces and ureters can be striking Some dilatation develops before 14 weeks and likely
E .
FIGURE 53-1 The 50th, 75th, and 90th percentiles for maternal renal caliceal diameters measured using sonography in 1395 pregnant women from 4 to 42 weeks' gestation. (Redrawn from Faundes A, Bricola-Filho M, Pinto e Silva JC: Dilatation of the urinary tract during pregnancy: proposal of a curve of maximal caliceal diameter by gestational age. Am J Obstet Gynecol 178: 1082, 1998.) from progesterone-induced relaxation of the muscularis. More marked dilatation is apparent beginning in midpregnancy because of more distal ureteral compression, especially on the right side (Faundes, 1998). There is also some vesicoureteral relux during pregnancy. Because of these physiological changes, the risk of upper urinary infection rises. Also, imaging studies done to evaluate urinary tract obstruction may occasionally be erroneously interpreted.