The aim of this study is to estimate the effectiveness and safety of L-arginine for preventing preeclampsia in high-risk patients.Design and method:
We performed a randomized, double-blind, placebo-controlled, clinical trial in 100 patients with high-risk factors for developing preeclampsia. Fifty subjects received L-arginine once a day, beginning from the 20th week of gestation until delivery. An additional 50 patients received homologated placebo. The subjects were monitored during the study and 14 days after they delivered to determine if preeclampsia was present. Doppler ultrasound was performed and blood samples were collected to determine fetal and maternal wellbeing.Results:
The placebo group had a higher number of cases of preeclampsia (11/47) compared with the L-arginine group (3/49) (X2 = 5.755 P = 0.01). The risk reduction was 0.26 (95% confidence interval [CI] 0.07–0.87), absolute risk reduction was 0.17 (95% CI 0.03–0.31), relative risk reduction was 0.74 (95% CI 0.29–0.93), and the number needed to treat was six (95% CI 3–29). Dyspepsia was more frequent in the L-arginine group (n = 13) than in the placebo group (n = 3, P = 0.008). Birth weight was higher in the L-arginine group (P = 0.03) and there was a smaller number of preterm births (P = 0.03) compared with the placebo group.Conclusions:
Administration of L-arginine is effective and safe for preventing preeclampsia.