The role of nitrates in the prevention of preeclampsia

Defective nitric oxide synthesis and nitric oxide-mediated vasodilatation is widely documented in the pathophysiology of preeclampsia, a leading cause of maternal and perinatal morbidity and mortality worldwide. Several studies demonstrated the beneficial role of nitric oxide agents, especially glyceryl trinitrate and L-arginine in reducing the blood pressure and improving the uteroplacental blood flow velocities. However, there is insufficient evidence on the efficacy and safety of these agents in the prevention of preeclampsia and its complications, as there are very few randomized controlled trials with small number of women. The aim of this review is to summarize and evaluate the role of nitrates in the prevention of preeclampsia based on the available evidence in the literature till date and suggestions for future research.Supplementation with L-arginine and antioxidant vitamins reduced the incidence of preeclampsia in women at high risk of preeclampsia [P 0.001, absolute risk reduction 0.17 (confidence interval 0.12-0.21)].On the basis of the recent evidence, nitric oxide agents may be beneficial in the prevention of preeclampsia. Randomized controlled trials initiated in the first trimester and using long-acting nitrates are needed in high-risk women to validate these findings.