REDUCED URINARY CALCIUM CREATININE RATIO PRECEDES PREECLAMPSIA AND INTRAUTERINE GROWTH RESTRICTION/

Objective: To determine if a decrease in urinary calcium/ creatinine r atios would precede preeclampsia, intrauterine growth restriction, or both. Methods: Ninety-eight patients at risk for preeclampsia were enr olled. The patients were either nulliparous or multigravida with chron ic hypertension, chronic renal disease, diabetes, or collagen vascular disease. Monthly 24-h urine collections were obtained, and excretion of calcium was expressed as a calcium/creatinine ratio. Patients were divided based on outcome criteria into normal (63), preeclamptic (22), intrauterine growth-restricted (8), and preeclamptic and intrauterine growth restricted (5). Analysis of variance tests were used to compar e calcium/creatinine ratios between groups at four gestational age int ervals (25-28, 29-32, 33-36, 37-40 weeks). Results: The mean calcium/c reatinine ratio in patients who were preeclamptic, intrauterine growth restricted, or both was significantly lower than those with a normal outcome (P < 0.005). Using the relative operating characteristic curve , a urinary calcium/creatinine ratio of less than or equal to 0.20 at 29-32 weeks' gestation was chosen as predictive for the development of preeclampsia, intrauterine growth restriction, or both with a sensiti vity of 73% and a specificity of 56%. Conclusion: Urinary calcium/crea tinine ratio of less than or equal to 0.20 at 29-32 weeks was associat ed with the subsequent development of preeclampsia, intrauterine growt h restriction, or both.