Arginine supplementation for improving maternal and neonatal outcomes in hypertensive disorder of pregnancy: a systematic review.

OBJECTIVE This meta-analysis was performed to assess whether arginine supplementation could reduce preeclampsia or eclampsia incidence and improve the outcomes of hypertensive disorders in pregnancy, and to evaluate the safety of L-arginine supplementation. METHODS The Cochrane Central Register of Controlled Trials (2011), MEDLINE (1980-2011) and Embase (1980-2011) were searched through July 2012, and randomized controlled trials (RCTs) comparing intravenous and/or oral L-arginine supplementation with placebo, or RCTs comparing any treatment with arginine were included. Qualities of RCTs were assessed with the Jadad method. Meta-analyses were performed with fixed- or random-effects models according to heterogeneity of studies. RESULTS Data from seven RCTs involving 916 patients were enrolled. The meta-analysis showed L-arginine was more effective in reducing preeclampsia or eclampsia incidence (odds ratio 0.384; 95% confidence limits 0.25, 0.58) than the placebo; meanwhile, L-arginine could prolong pregnancy weeks (MD 11.54; 95% CL 5.23, 17.85) than placebo; and its effect on blood pressure was unbalanced (diastolic pressure (MD 4.86; 95% CL 4.19, 5.52) and systolic pressure (MD 3.20; 95% CL -1.54, 7.94)) while the difference in increased neonatal weight (MD 256.24; 95% CL -28.66, 541.13) was not clear. Three of these studies reported some adverse effects, and no teratogenic or lethal effects were noted. CONCLUSION This study demonstrates L-arginine supplementation is superior to placebo in lowering diastolic pressure and prolonging pregnancy in patients with gestational hypertension with or without proteinuria, but the effect on lowering systolic pressure and increasing neonatal weight was not statistically significant.