Abstract

Introduction: Hypertensive disorders during pregnancy is one of the most important complications of pregnancy that account for three most important causes of maternal mortality together with hemorrhage and infection. Methods: In this review article, the databases Medline, Cochrane, Science Direct, and Google Scholar were thoroughly searched to identify The relationship between hemoglobin and hematocrit in the first and second trimester of pregnancy and the incidence of preeclampsia. In this review, the papers published until early January 2017 that were conducted to study The relationship between hemoglobin and hematocrit in the first and second trimester of pregnancy and the incidence of preeclampsia were selected. Results: Early diagnosis of preeclampsia is one of the most important functions of pregnancy cares. However, there is still no reliable criterion for the early diagnosis of this disease Based on the existing evidences of the pregnancies resulted in preeclampsia, the vascular wall of the spiral arteries is muscular and thick and the invasion into the trophoblast is incomplete. Discussion and Conclusion: If hematocrit level of the first trimester is more than 43, it has to do with the preeclampsia at the end of the third trimester . Every year, 75 thousand maternal deaths occur owing to hypertensive disorders. Although numerous studies have been conducted on this disease, its cause is still unknown.