Urinary albumin excretion and 24-hour blood pressure as predictors of pre-eclampsia in Type I diabetes

Aims/hypothesis. To evaluate the value of 24-h blood pressure monitoring co mpared to office blood pressure and urinary albumin excretion in predicting pre-eclampsia in Type I (insulin-dependent) diabetes mellitus. Methods. The study included 136 consecutive pregnancies in Caucasian women with Type I diabetes before gestation without diabetic nephropathy, anamnes tic hypertension or early abortion. Values of urinary albumin excretion and office blood pressure before pregnancy and the HbA(1C) value at the time o f conception were obtained. Microalbuminuria was defined as urinary albumin excretion of 30-300 mg/24 h in two out of three consecutive urine samples. Single measurements of 24-h urinary albumin excretion, office blood pressu re and HbA(1C) were done five 5 times during pregnancy. In a subgroup of 74 women 24-h blood pressure measurements were done at 10 and 28 weeks of ges tation. Pre-eclampsia was defined as office blood pressure higher than 140/ 90 mmHg accompanied by proteinuria above 0.3 g/24 h later than 20 weeks of gestation. Results. Urinary albumin excretion and systolic blood pressure were higher before and throughout pregnancy in 14 women developing pre-eclampsia compar ed with women remaining normotensive (p < 0.001; p < 0.05, respectively). B y logistic regression analysis the best predictor for pre-eclampsia was mic roalbuminuria before pregnancy (p < 0.05) with no additive predictive effec t of 24-h blood pressure or office blood pressure measurement. The night:da y ratio of blood pressure was similar in the two groups. Conclusion/interpretation. Microalbuminuria before pregnancy is the stronge st predictor of pre-eclampsia in Type I diabetes. Measuring 24-h blood pres sure early in pregnancy did not improve the ability to identify women at ri sk.