Background: As there are some limited studies, we aimed to evaluate the relation between Idiopathic hematuria and preeclampsia in Iranian nuliparas.

  Methods: 400 women between 11th and 21th weeks of pregnancies without UTI and other kidney disease were enrolled. 200 women, had shown Idiopathic hematuria, matched by age and other condition to others. Mean, median, range, standard deviation, frequency and frequency percentage were determined using statistical software SPSS V.19 and descriptive analyses. For comparison of qualitative means, independent T test was used after the normal distribution of data to determine .It is followed by 1-sample KS. K.s-Ttest-Chi square statistical test was used for the comparison of qualitative ratios. In all tests, significance level was considered as two tails, and p<0. 05.

  Results: 31 of hematuric pregnants (%15.4) and 14 of non-hematuric women (%7.2), developed preeclampsia. Which was significant (PR=1.91, p=0.002 and has shown a two- fold increased risk of preeclampsia among hematuric women. However there were no significant correlation between gestational hypertension and hematuric event (PR=0.69, p=0.12).

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