Spectral analysis of heart variability in the newborn infant

We investigated the relationship between spectral power and both mean heart rate (HR) and heart rate variability (HRV). Spectral power was calculated using digital heart rate recordings from term infants. Regression analysis revealed a positive correlation between low-frequency (LF) sympathetic power and HR, and a negative correlation between high-frequency (HF) parasympathetic power and HR. HRV correlated positively in all regions of the power spectrum. In awake infants, the contribution of HF power to total power (HF/TP) was significantly decreased. LF power tended to be greater, however, this trend was not statistically significant. By following expected autonomic patterns, the findings of this study confirm that spectral analysis provides a noninvasive method for the assessment of autonomic activity influencing the newborn heart. The correlation between spectral power and HRV can serve as an additional tool in the study of autonomic dysfunction.     

Influence of immediate newborn care on infant adaptation to the environment

The indicators of newborns' adaptation during 75 min after birth were compared in three randomised groups of full-term newborns: skin-to-skin contact (group I), swaddled newborns beside the mother (group II), swaddled and separated from the mother (group III). The changes in skin temperature, blood glucose, pH, heart rate, respiration rate and crying time were studied. All the above characteristics but pH were significantly the most favourable for infants in the skin-to-skin group. The analysis of individual trends of changes in skin temperature indicated that for all but two newborns not separated from the mother (skin-to-skin or lying besides) the temperature was growing during the observation period, whereas in the separated group, six newborns (27%) had unstable not growing temperature. The mean level of blood glucose was the highest in skin-to-skin group (60.1 mg/dl), lower in group of swaddled and lying beside mother (52.5 mg/dl) and the lowest (49.6 mg/dl) in the separated group. The mean duration of crying time in the skin-to-skin contact was a little shorter than in the group of newborns lying besides the mother and more than three times shorter than in the separated group. The observed number of episodes of crying were 7, 17 and 38 in the three groups respectively. All results indicated that skin-to-skin contact is optimal for newborns', adaptation after birth especially as a protection against hypothermia and hypoglycaemia.     

Bone maturation in the fetus and newborn infant]

On the basis of a study of X-ray films of the lower limbs of 994 babies (included 245 hypotrophics) a "bone age" scale of the fetus between 28 and 42 weeks of gestation has been established. The Acheson's method has been used and the bone age determined by addition of notes given to different evolutive phases of the first five ossification centers of the ankle and the knee. To more practical purpose, the results of boys and girls have been joined, although the bone age is in advance among the girls and a theorical scale established with the 10th, 50th and 90th percentiles curves. The comparison with the curves established among 245 hypotrophic newborns, seems to prove that the bone age is a more resistant criteria to malnutrition than the weight and even the length. This new criteria to determine the fetal age does not escape to the criticisms given to the other existing criteria, but radiograph is an objective and fixed document. Its repetition allows to follow the growth of the child and probably to study the role of various factors, mainly nutritional, on this growth. The measure of the length of the tibia and of its increament on the same X-ray films is an other possible method of great interest for the same purpose.     

Immunologic findings in the newborn infant. II. Studies of humoral immunity, reference values of immunologic studies in the newborn infant

After dealing with cellular immune aspects in the first part of the paper the authors describe in the second part the state of humoral immunity in healthy full-term newborns aged one to three days. The number of complementreceptor lymphocytes was 17.0 +/- 8.9% or 0.75 +/- 0.51 (mean +/- S.D.) respectively, with the EAC-rosette method. The percentage value equalled that of adults but the absolute count is higher. Using the immunodiffusion method IgA was detectable in 4 out of 132 newborns only 8.86 +/- 2.52 g/l (mean +/- S.D.) was measured as an average IgG concentration. With regard to the IgM content the values often exceeded 0.30 g/l in newborns of mothers who had been suffering from pre-eclampsia. Their mean value of 0.35 +/- 0.21 g/l, too, was significantly higher than 0.13 +/- 0.08 in the resting infants. Raised IgM values frequently coincided with high spontaneous transformation activities in lymphocyte cultures. The possible causes are discussed. Complement C3-component was measured on average with 0.78 +/- 0.18 g/l and C4-component with 0.34 +/- 0.11 g/l. When calculating reference values for newborns the results of infants with maternal pre-eclampsia have been omitted.