Dietary supplementation with L-arginine or placebo in women with pre-eclampsia

To investigate the effect of dietary intake of the NO-donor L-arginine on the diastolic blood pressure in women with pre-eclampsia.

A randomized double-blind study was designed to compare the effect of L-arginine and placebo in pre-eclamptic women with gestational length ranging from 28+0 to 36+0 weeks. The women received orally 12 g of L-arginine or placebo daily for up to 5 days. The primary end-point was to identify a difference in diastolic blood pressure alteration between the two groups after 2 days of intervention. Secondary end-points included the interval from study start to delivery, the proportion of women delivered after 2, 5 or 10 days from treatment start and mean birth weight.

There was no statistically significant alteration in diastolic blood pressure in the L-arginine group compared with the placebo group after 2 days of treatment (p = 0.4). No differences in the proportions of women delivered by day 2, 5 or 10 after study start, in the mean interval from study start to delivery, or in mean birth weight percentile were observed between the two groups.

Oral L-arginine supplementation did not reduce mean diastolic blood pressure after 2 days of treatment compared with placebo in pre-eclamptic patients with gestational length varying from 28 to 36 weeks. Whether L-arginine treatment could be clinically beneficial for the mother or the fetus if started earlier in the disease process than for the women in our study remains to be seen.