Background and Aims Nitric oxide (NO) is a vasodilator produced from different groups of nitric oxide synthases and plays an important role in regulation of vascular tone and blood flow in different organs. The aim of this study is to determine the connection between intrauterine growth inhibition and NO activity in late preterm infants.
Methods Newborns with gestational age of 34–36 weeks and birth weight of 1200–2600 g were allocated to two groups: 21 infants with normal growth parameters were classified as first group and 15 intrauterine growth restricted (IUGR) infants were included in second group. Gestational age was assessed by the last menstrual period and confirmed by scale of Ballard et al. Plasma and urine samples of infants were collected on the first day of life. Nitric oxide concentration quantified by principle based on using the enzyme Nitrate Reductase to convert nitrate to nitrite.
Results Mean plasma nitrat products were higher (p<0.05) in second group infants(42.6±7.3 µM/L), than in first group (59±7.3 µM/L). Statistically true rising (p<0.01) was noted in urine NO level of IUGR infants, where mean NO level was 1.4 times higher compared with first group newborns.
Conclusion Intrauterine growth retardation is associated with high NO production of infants at an early neonatal period, which might indicate intrauterine activation of NO sources of fetus.