Efficacy of L-Arginine for Preventing Preeclampsia and Improving Maternal and Neonatal Outcomes in High-Risk Pregnancies: A Systematic Review and Meta-Analysis.

Preeclampsia (PE) remains a significant cause of maternal and neonatal morbidity and mortality, particularly in high-risk pregnancies. The present study aims to assess the efficacy of L-arginine supplementation in preventing PE and improving maternal and neonatal outcomes in high-risk pregnancies. We searched international databases (ISI, PubMed, Scopus, and Embase) and extracted studies that evaluated the efficacy of L-arginine for preventing PE and improving maternal and neonatal outcomes in high-risk pregnancies. The data collected were analysed utilising the random-effects model in Stata (version 15). Out of the collected studies, 10 met the eligibility criteria, comprising a total sample size of 1165 subjects (586 cases and 584 controls). The mean age of the cases was 28 ± 5.05 years, while that of the controls was 27.32 ± 4.58 years. The results revealed that L-arginine was more effective in reducing the incidence of PE than placebo [odds ratio (OR)=0.36, 95% confidence interval (CI): 0.17, 0.77]. Also, the results showed no statistically significant difference between the two groups in systolic blood pressure (SBP; standard mean difference (SMD): -0.35, 95% CI: -91, 21) and diastolic blood pressure (DBP; SMD: -0.50, 95% CI: -1.08, 0.07). There was a statistically significant difference in neonatal birth weight between the two groups (SMD: -0.16, 95% CI: -31, -0.01). No statistically significant difference existed between the two groups in terms of gestational age (SMD: 0.6, 95% CI: -0.06, 0.18). Furthermore, there was no significant difference between the two groups in the APGAR score at one minute (SMD: 0.40, 95% CI: -0.02, 0.82). Our findings revealed that L-arginine supplementation during pregnancy reduced the incidence of PE in high-risk pregnancies. However, it does not significantly improve maternal and neonatal outcomes.