Increased risk of preeclampsia among nulliparous pregnant women with idiopathic hematuria.

Objective: Our purpose was to determine the risk of preeclampsia and gestational hypertension among nulliparous pregnant women with idiopathic hematuria.

Study Design: We conducted a prospective cohort study using data from the trial of Calcium for Preeclampsia Prevention (CPEP). Participants were followed up from screening and enrollment (gestational weeks 11-21) throughout pregnancy. Our analysis was limited to women who had been followed up to at least 20 weeks' gestation, had outcome information available, and were not suspected to have had urolithiasis. Surveillance for hematuria was conducted with dipsticks on clean-catch urine specimens obtained at research clinic visits. Idiopathic hematuria was defined as hematuria identified at regularly scheduled clinic visits in the absence of urinary tract infection and before the onset of labor. Logistic regression was used to estimate the risk of preeclampsia among women with hematuria compared with women without hematuria.

Results: Among the 4307 women available for analysis, 132 (3%) had idiopathic hematuria during pregnancy. Idiopathic hematuria was associated with an almost 2-fold increased odds for development of preeclampsia (adjusted odds ratio [aOR] = 1.89, 95% CI 1.12- 3.18) but not with increased odds of gestational hypertension (aOR = 0.78, 95% CI 0.46-1.32).

Conclusions: Idiopathic hematuria identified during pregnancy is associated with greater risk of preeclampsia but not gestational hypertension.