Ultrasound evaluation of intrauterine growth restriction therapy by a nitric oxide donor (L-arginine)

There are numerous methods available of treating intrauterine growth restriction but their results are still not satisfactory. Currently, we are conducting a research project whose main aim is based on the use of the nitric oxide (NO) donor L-arginine in growth restriction therapy. The main aim of this study was the ultrasound evaluation of the efficacy of this therapy based on biometric measurements (the estimated fetal weight) compared with the estimated weight of newborn children.

The investigated group comprised two randomly chosen groups of pregnant women with ultrasound-diagnosed intrauterine growth restriction (biometry < 10th centile for gestation age): 78 patients were treated by L-arginine 3 g daily orally for 20 days; and 30 patients, not treated, acted as the control group.

The ultrasound estimation of fetal weight at the start and at the end of the treatment showed a mean increase of 642 g (SE 90 g) using the Shepard method, and 648 g (SE 94 g) using the Hadlock method, respectively. By comparison, within the control group a mean value increase of 395 g (SE 77 g) was found, using the Shepard method, and 404 g (SE 82 g) using the Hadlock method, respectively. There was a significant statistical difference when comparing the estimated fetal weight increase in both methods: p=0.008 for the Shepard calculation and p=0.012 for the Hadlock calculation. The weight of the newborn infants was also evaluated: in the treated group the mean value was 2823 g (SE 85 g) and in the untreated group the mean value was 2495 g (SE 147 g). There was a significant (p=0.027) difference, showing a positive effect of the treatment on the weight of newborns. In the treated group the percentage of growth-retarded newborns was 29% while in the untreated group it was 73%. A significant difference has been found (p < 0.01) between both of the groups of newborns.

The ultrasound evaluation of the estimated fetal weight and the birth weight of the newborns showed an improvement: there was an acceleration of fetal development in the L-arginine-treated group of pregnant women as compared with the untreated group. The ultrasound evaluation of the estimated fetal weight is a good diagnostic tool, properly monitoring the efficacy of the L-arginine treatment of the growth-retarded fetuses.