Vegetative regulation in the first three months of life in premature infants born with intrauterine growth retardation

Abstract

Goal. To study the dynamics of vegetative states in preterm infants with intrauterine growth retardation (IUGR) during the first three months of life.
 Materials and methods. Examined 34 preterm infants with IUGR – 1st group (GA – 33,3 ± 1,4 weeks, body weight – 1557,8 ± 63,8 g, length – 41,2 ± 1,7 cm) at the age of 5 days and 3 months of life; 51 premature infants without IUGR (GA – 33,2 ± 1,02 weeks, body weight 2062,0 ± 63,9 grams, length – 44,0 ± 1,4 cm) – 2nd group; a control group included 31 healthy full-term infants (GA – 38,8 ± 1,5 weeks, body weight – 3355,4 ± 147,6 grams, length – 52,7 ± 2,3 cm). The vegetative tester “Polispektr-8E/88” (2000 Hz, 12 bit), from the Russian firm “Neurosoft”, was used. Indicators of the cardiointervalogram (CIG) and spectrogram were determined in the baseline sample and in the orthostatic test (tilt-test).
 Results. Among the indicators of CIG there was a noticeable decrease of mode (Mo, s) in 2 groups of preterm infants at 5 days of life (p < 0,05) and an increase in stress-index by 3 months of age in 1 group (p < 0,05). The study revealed the predominance in the structure of the wave spectrum of the VLF-component in all groups of children to 3 months; children 1 group had a lower value of this indicator, but they also had a higher proportion of high frequency component (HF, %) (p < 0,05). Vagotonic initial vegetative tonus (IVT) was defined only in 1 group, while the frequency of sympathicotonic and hypersympathicotonic IVT decreased (p < 0,05). Asympathicotonia vegetative reactivity (AST VR) in premature infants with IUGR was increased from 38, to 72,7% to 3 months (p < 0,05).
 Conclusion. The study revealed the lack of influence of the Central contour vegetative regulation, more intense adaptation and high exhaustion of the functional reserve in preterm infants with IUGR to 3 months of life.