Brazelton scale and physical size correlates of neonatal cry features

Developmental Organization, Stress, and Illness

The link between behavioral responsiveness to stress and subsequent health has been demonstrated in adults but not in infants and very young children. The ability of infants to suppress responding to acutely painful events was examined both as a function of neonatal status and as a predictor of incidence of illness at 18 to 24 months. Responding to stress in early infancy was predictive of later health but the nature of the relation depended on the maturity of the child.

A Synergistic Process Approach to the Study of Prenatal Malnutrition

The multifactorial relationship between nutrition and other intrauterine influences seems to exert a combined effect on birthweight, particularly during the third trimester. Full-term infants who may have suffered fetal malnutrition, as indicated by the weight for-length ratio of the ponderal index, were compared with full weight controls on the Brazelton Neonatal Behavioral Assessment Scale and on acoustic features of the infant's pain cry. The underweight infants showed poorer performance than the controls on the four Brazelton scale dimension scores of social interaction, motor processes, organization of state, and physiological organization. The cry of the underweight infants had a shorter fist cry length, longer expiratory period, fewer harmonics, and a higher fundamental frequency than the full weight infants. It was suggested that the Brazelton scale and cry analysis may be useful in the assessment of pediatrically healthy infants who may be at risk. A synergistic model was proposed in which nutritional effects are viewed within the obstetric and reproductive history of the mother and the broader sociocultural environment of the family. The infant at risk becomes part of a feedback system in which he affects and is affected by the caregiving environment.

Perinatally Influenced Autonomic System Fluctuations Drive Infant Vocal Sequences

The variable vocal behavior of human infants is the scaffolding upon which speech and social interactions develop. It is important to know what factors drive this developmentally critical behavioral output. Using marmoset monkeys as a model system, we first addressed whether the initial conditions for vocal output and its sequential structure are perinatally influenced. Using dizygotic twins and Markov analyses of their vocal sequences, we found that in the first postnatal week, twins had more similar vocal sequences to each other than to their non-twin siblings. Moreover, both twins and their siblings had more vocal sequence similarity with each other than with non-sibling infants. Using electromyography, we then investigated the physiological basis of vocal sequence structure by measuring respiration and arousal levels (via changes in heart rate). We tested the hypothesis that early-life influences on vocal output are via fluctuations of the autonomic nervous system (ANS) mediated by vocal biomechanics. We found that arousal levels fluctuate at ∼0.1 Hz (the Mayer wave) and that this slow oscillation modulates the amplitude of the faster, ∼1.0 Hz respiratory rhythm. The systematic changes in respiratory amplitude result in the different vocalizations that comprise infant vocal sequences. Among twins, the temporal structure of arousal level changes was similar and therefore indicates why their vocal sequences were similar. Our study shows that vocal sequences are tightly linked to respiratory patterns that are modulated by ANS fluctuations and that the temporal structure of ANS fluctuations is perinatally influenced.

Measurement of neonatal responses to painful stimuli: a research review

The measurement of neonatal responses to painful stimuli remains a significant clinical problem. Although numerous measures have been evaluated, instruments that are valid, reliable, and clinically feasible are not yet available. The purpose of this paper is to critique the studies that have been done using biochemical, physiological, and behavioral measures to evaluate neonatal responses to painful stimuli. Specific issues regarding measurement in premature and critically ill neonates are emphasized. The intent of this review and critique of the literature is to stimulate additional research into the assessment of neonatal pain.

Behavioral intervention and post-natal growth in full-term intrauterine growth retarded (IUGR) infants

The purpose of this study was twofold: (1) to describe the patterns of post-natal growth in full-term infants as a function of IUGR and (2) to assess the impact of an individualized behavioral feeding intervention with the mothers on these patterns of infant growth. Eighty-eight (88) full-term infants, including 54 with IUGR, half of whom received behavioral intervention were included. Weight, length, skinfold thickness, head circumference and Ponderal Index were measured at birth and at 1, 4, 8, 12, and 18 months. Results show positive intervention effects between birth and 1 month in weight, length, skinfold thickness, and Ponderal Index. However, there were no intervention effects at subsequent ages. No evidence was found for catch-up growth in full-term IUGR infants in weight, length, and head circumference. We conclude that an individualized behavioral feeding intervention can accelerate early growth in IUGR infants, but the positive effects on growth are only seen while the intervention lasts (between birth and 1 month). On most parameters of physical growth, there is no lasting catch-up growth over the first 18 months in IUGR full-term infants.

Newborns' sleep-wake patterns: the role of maternal, delivery and infant factors

OBJECTIVE

The purpose of this study was to assess the sleep-wake patterns of fullterm (> or = 37 weeks) newborns and to evaluate the effects of specific factors including maternal gestational diabetes, infant size and anthropometric measures, gender, gestational age and delivery variables.

METHODS

Two-hundred twenty newborns were studied in the hospital nursery for a continuous 24-h period with miniature activity monitors attached to the infants' ankles. The sample consisted of 102 infants of gestational diabetic mothers (IGDM) and 118 controls. Anthropometric measurements were obtained and maternal and infant characteristics were recorded.

RESULTS

The newborns had a discernible diurnal sleep pattern and slept twice as much during the nighttime as daytime hours (P < 0.001). Higher skinfold measurements correlated significantly with increased quiet and motionless sleep (P < 0.05) for the IGDM but not for controls. Sleep of infants born at later gestational ages was characterized by increased percent of quiet and motionless sleep (P < 0.0001). No direct gender effects were identified.

CONCLUSIONS

Multiple factors were associated with the sleep-wake patterns of the newborns on our study cohort including maternal glucose values during pregnancy, increased measures of adiposity in IGDM, increased gestational age, mode of delivery and delivery Sequence. Investigation of the sleep-wake characteristics of neonates using activity monitors is a noninvasive method for gaining new understanding of the relationships between sleep wake activity patterns and infant characteristics.

Factors that influence the behavioral pain responses of premature infants

The responses of preterm neonates to acute tissue-damaging stimuli have been described. However, factors which influence these responses have received little attention. In this study, we observed 124 premature infants before, during and after a routine heel lance and determined how two contextual variables (severity of illness and behavioral state) influenced their behavioral responses. Significant changes in facial actions occurred between baseline and the most invasive phase of the heel lance procedure, stick. The fundamental frequency, harmonic structure and peak spectral energy of the infant's cry were also significantly increased during the stick phase. Behavioral state was found to influence the facial action variables and severity of illness modified the acoustic cry variables. Accurate identification of pain in premature infants requires consideration of factors that influence their response.

Rhythmic organization of the sound of infant crying

The purpose of the present study was to examine the temporal morphology and rhythmic structure underlying the repeated bursts of expiratory sounds in a sustained bout of crying of twenty-three 1-month-old infants. Durations of expiratory sounds and bursts were determined from a 90-s bout of naturally occurring cries recorded in the home before feeding. Results indicated wide individual differences in temporal morphology between infants and within infant cry sounds. Binary spectrum analysis of the presence of expiratory sounds in the cry sound detected rhythms in temporal organization at a wide range of dominant frequencies. Spectral complexity (higher numbers of peaks in the power spectrum) was related to a longer time since infants were last fed and shorter expiratory sounds. Results emphasize the importance of viewing cries of young infants as dynamic signals. An ontogenetic history of the rhythms of infant cry sounds may contribute to understanding organismic and environmental experiences which contribute to development.

Sound spectrographic analysis of pain cry in preterm infants

Sound spectrographic cry analysis was performed on 302 cries of 48 preterm infants born at 30-37 gestational weeks. The cries were recorded during the first week of life and thereafter weekly until the infants were discharged. The control series comprised 54 cries from 27 fullterm healthy infants. The results showed that the cries of the smallest prematures compared with the controls were shorter, more high-pitched, and included bi-phonation and glide more often. The cry characteristics changed with increasing conceptual age and the older the child the more the cry pattern resembled that of the fullterm. The cries of the preterm infants when they had reached 38 conceptual weeks were similar to those of newly born fullterm infants. The results indicate that the gestational age should be taken into consideration in cry analysis.