Effects of L-arginine on preeclampsia risks and maternal and neonatal outcomes: A systematic review and meta-analysis

Objective: To summarize whether the supplementation of L-arginine in pregnant women helps in management of preeclampsia and its impact on maternal and neonatal outcomes. Methods: Studies conducted from the past 17 years (1999 to 2016). were referred from database like Cochrane Central Registry of Controlled Trials (CENTRAL), Scopus, Google Scholar and PubMed. Out of 134 studies, 7 studies were included. L-arginine versus placebo was considered for quantitative analysis. Modified Cochrane data extraction form was used to collect the data. The risk of bias was assessed using Cochrane’s risk of bias assessment tool in RevMan 5.4 and the summary of findings was determined using GradePro software. Results: L-arginine showed a significant reduction of preeclampsia [odds ratio (OR) 0.38; 95% confidence interval (CI) 0.25, 0.58)]. There was a significant reduction in systolic blood pressure [mean difference (MD) -2.47; 95% CI -4.53, -0.42] and diastolic blood pressure (MD -0.97; 95% CI -3.83, 1.89). The effects of L-arginine on secondary outcomes like maternal gestational age, latency, neonatal weight, and appearance, pulse, grimace, activity, respiration (APGAR) score at 1st and 5th minute were not statistically significant. Conclusions: L-arginine supplementation is effective in lowering systolic and diastolic blood pressure of preeclamptic patients. However, it has no noticeable effects on maternal and neonatal outcomes.