RENAL-FUNCTION IN GRAVIDAS WITH CHRONIC HYPERTENSION WITH AND WITHOUTSUPERIMPOSED PREECLAMPSIA

Objective: To assess the predictive value of different renal laborator y tests for development of superimposed preeclampsia in women with chr onic hypertension. Methods: Thirty-seven pregnant patients with chroni c hypertension and 14 healthy pregnant women were examined at 11-13, 1 9-21, 27-29, and 31-33 weeks with the following laboratory tests: plas ma concentrations of creatinine, urea and uric acid, urinary excretion of albumin, and calcium; erythrocyte excretion was investigated only at 11-13 and 27-29 weeks. Results: Among the patients who developed su perimposed preeclampsia (30%), a pathologic urinary albumin excretion, i.e., microalbuminuria, was seen in 30% at 31-33 weeks pregnancy, as compared to none among patients with chronic hypertension who did not develop this complication and 7% in the normotensive women (P < 0.05, chi-square test). There was no difference between the groups at the ea rlier gestational ages. Plasma urea concentration tended to be lower a mong the normotensive women than in the other two groups only at 19-21 and 27-29 weeks (P < 0.05, P = 0.065, respectively, one-way ANOVA). P lasma urea levels tended to increase with gestational length in those with superimposed preeclampsia, whereas it decreased in the other two groups (P<0.05, ANOVA with repeated measures). The other laboratory pa rameters differed in no way between the three groups. Conclusion: Bloo d and urine sampling every 4 to 8 weeks for assessment of renal functi on in pregnant women with chronic hypertension seems to be of limited value for the prediction of superimposed preeclampsia.