Calcium-to-Creatinine Ratio in a Spot Sample of Urine, for Early Prediction of Hypertensive Disorders of Pregnancy

Background - Hypertensive disorders complicate 5-10 % of all pregnancies. Various methods for screening have been studied to identify pregnant women at risk of development of preeclampsia, but no ideal screening test has been identified so far. The objective of this study was to determine the efficacy of urinary calcium-to-creatinine ratio, in a spot urine sample, for the prediction of preeclampsia in asymptomatic pregnant women between 18 and 24 weeks of gestation. Methods - This study was done on 106 patients presenting to the antenatal clinic in the Department of Obstetrics and Gynecology at VSS Medical College and Hospital. A random urinary calcium-to-creatinine ratio of all the patients was analyzed. The urinary calcium level and creatinine was analyzed by suitable method. A value of less than or equal to 0.04 was considered positive. Results - 106 patients were recruited in the study. 6 lost to follow up. Out of the 12 subjects with urinary CCR less than 0.04, 8 developed gestational hypertension, 2 developed preeclampsia, and 2 remained normotensive. In 88 patients with CCR> 0.04, 4 developed gestational hypertension, none preeclampsia and 84 were normotensive. Interpretation and Conclusion - On statistical analysis, it was found that when CCR alone is taken as high-risk factor for prediction of preeclampsia, P< 0.001 was statistically significant, sensitivity was 71.42%%, specificity 97.67%, PPV 83.33%, NPV 95.45 %, and diagnostic accuracy 94%. So this test was satisfactory as an early predictor for the development of preeclampsia.