OBJECTIVETo investigate the therapeutic effect of L-arginine (L-Arg) administration on fetus growth retardation (FGR) due to pregnancy-induced hypertension and explore its mechanism.

METHODSSixty-eight pregnant women with pregnancy-induced hypertension and FGR were enrolled in this study, and 25 of them were given L-Arg in addition to routine therapy. Umbilical artery flow parameters and serum NO concentrations in maternal and umbilical blood were measured, and the therapeutic effects were evaluated according to neonatal birth weight.

RESULTSL-Arg therapy markedly decreased the systolic/diastolic value, pulse index and resistant index (P=0.000,0), while increased the fast blood velocity rate(P=0.000,0). NO contents in maternal and umbilical blood were 60.45-/+22.68 and 28.45-/+11.35 micromol/L in L-Arg group, respectively, significantly higher than those in routine treatment group (P=0.000,0 and 0.001,7, respectively) but lower than those in the control group (P=0.000,8 and 0.000,0, respectively). The neonatal birth weights were 2.9-/+0.3 kg in L-Arg group, significantly higher than that in routine treatment group (2.7-/+0.3 kg, P=0.006,8) and similar with that of the control group (3012.9-/+295.9 g, P=0.176,2).

CONCLUSIONL-Arg promote intrauterine growth of the fetus by increasing NO production and improving the umbilical artery flow in pregnant women with pregnancy-induced hypertension and FGR.