Renal disease in pregnancy

Renal diseases may be of primary origin, or arise as manifestations of systemic disorders. In preg-nancy, both their nature and incidence are subject to modification. A few, such as preeclampsia, are peculiar to it; others, which give rise to adverse metabolic effects, as in chronic renal failure, reduce fertility and have a correspondingly low incidence. The physiological state of pregnancy significantly alters body homeostasis. Some of the changes affect the kidney and urinary tract directly (Sims, 1968; Berman, 1974); compared to the non-pregnant state there is a 50 % increase in glomerular filtration rate and a 25 % increase in renal plasma flow with appropriate lowerings of serum creatinine and urea levels. Glycosuria is more common and serum uric acid levels are raised. Urinary conducting pathways are also affected. By the end of the first trimester the renal pelvicalyces and ureters, particularly on the right side, show diminished peristalsis-an atonic state which persists late into pregnancy and may remain for several years, if not indefinitely (Dure-Smith, 1968). On a more general basis, but with important renal implications, is an increase in blood coagulability, a reflection of raised levels of several clotting factors and depressed fibrinolytic activit