Dynamics of oralrespiratory coordination in full-term and preterm infants: I. Comparisons at 38-40 weeks postconceptional age

This study compares the coordination of pacifier sucking and breathing between healthy full-term, low risk preterm, and high risk preterm infants at 38–40 weeks postconceptional age. High and low risk preterm infants did not differ in overall score on a neurobehavioral examination (NAPI), but infants in the high risk group differed from the others in breathing frequency and in the coordination of breathing and sucking rhythms. For infants in the high risk group, sucking had less influence on respiratory frequency and patterns of coordination between the frequencies of sucking and breathing were simpler. Oral–respiratory coordination may be a useful marker of infants at risk for later speech problems.     

Emotional and neuroendocrine regulation in very preterm and full-term infants at six months of age

Emotional and neuroendocrine regulation have been shown to be associated. However, results are inconsistent. This paper explores the functioning and relationships between these two systems in 54 healthy preterm and 25 full-term born infants at six months of age. Results showed significant differences between very preterm and full-term children in emotional intensity and regulation, as well as in neuroendocrine regulation. No evidence of an association between neuroendocrine and emotional regulations was found. Results suggest a possible delay in the maturation of the neuroendocrine system as well as in emotional regulation in very preterm infants.     

Tonic and phasic orientation in full-term and preterm infants

Thirty-three full-term infants and thirty-eight preterm infants (on average born at 30 weeks gestation) were tested for their latency to turn toward checkered stimulus patterns (phasic orienting or "attention-getting") and for the duration of their initial fixation (tonic orienting or "attention-holding"). Plotted against the logarithm of the subjects' postconceptional age, turning latency fell linearly between 36 and 120 weeks, while fixation time fell abruptly at 53 weeks. Preterm and full-term infants showed the same developmental trends, implying that both of these attentional behaviors are biologically timetabled and that neither is greatly affected by premature extrauterine experience. Unexpectedly, phasic orientation in the first 30 postnatal days was significantly faster in preterm than in full-term infants, and fixation times failed to differ. Despite the necessary functional integration of phasic and tonic orienting in mature visual scanning and attention, the present results suggest an independence in their early postnatal development and that neither is mature at birth.     

Emotional interaction in a group of preterm infants at 3 and 6 months of corrected age

Twenty preterm infants (birthweight<1500 g) and 20 healthy fullterm infants were compared with respect to emotional interaction with their mothers in a face‐to‐face situation at 3 months of age and in a feeding situation at 6 months of age (ages corrected for preterm birth). The assessed outcome was analysed with respect to infant variables (group, gender, gestational age, birthweight and neonatal risk factors) and maternal variables (age, education and parity). The outcomes at 3 and 6 months of age were also compared with findings of Griffiths’ testing at 10 months of age. At 3 months of age, the findings reveal no significant difference between the two groups with respect to emotional interaction. Maternal variables are more important for this interaction than are infant variables. The mother's level of formal education has a significant impact in both groups. In the group of fullterm infants, significantly lower scores for interaction are obtained by first‐time mothers in comparison with multi‐parae mothers. At 6 months of age, the difference between fullterm and preterm infants is significant. The preterm infants and their mothers now relate to one another more poorly than is the case for the fullterm dyads. These findings suggest that the difficulties encountered by the preterm infant emerge with time. Emotional interaction at this age and the results of Griffiths’ testing 4 months later are significantly correlated. Copyright © 1999 John Wiley & Sons, Ltd.     

Regulatory competence and social communication in term and preterm infants at 12 months corrected age. Results from a randomized controlled trial

Temperamental regulatory competence and social communication in term and preterm infants at 12 months corrected age was studied in a randomized controlled intervention trial aimed at enhancing maternal sensitive responsiveness. Surviving infants <2000 g from a geographically defined area were randomized to an intervention (71) or a control group (69), and compared with term infants (74). The intervention was a modified version of the "Mother-Infant Transaction Program". Regulatory competence was measured with the Infant Behavior Questionnaire, and social communication with the Early Social Communication Scales. Preterm intervention infants with low regulatory competence had higher responding to joint attention than preterm control infants. A sensitizing intervention may moderate the association between temperament and social communication, and thus allow an alternative functional outlet for preterm infants low in regulatory competence. The finding may have implications for conceptualizations of the role of early sensitizing interventions in promoting important developmental outcomes for premature infants.     

Hormonal sensitivity of preterm versus full-term infants to the effects of maternal depression

Comparisons were made of differences in the hormonal sensitivity of preterm versus full-term infants to maternal depression, as reflected in children's cortisol levels. In Study 1 (N=25), a comparison was made between preterm versus healthy full-term children. In Study 2 (N=80), a comparison was made between preterm infants and full-term infants with mild or moderate medical problems. Preterm infants were found to be highly reactive to maternal depression (as measured by the Beck Depression Inventory). That is, they demonstrated higher cortisol levels when paired with depressed mothers and lower cortisol levels when paired with non-depressed mothers. No equivalent effects were found for children who were full-term, even when they had experienced other medical problems at birth. It was concluded that premature infants are exceptionally sensitive to the "emotional climate" in their home environment. As a result, they may manifest very different hormonal outcomes--with implications for their later development.     

Face-to-face interaction in term and preterm infants

Previous research has found that mothers of preterm infants work harder in a face-to-face situation with their infants than mothers of term infants. Data have also revealed that preterm infants are less responsive than term infants in a social interaction. To date, there have been few studies that have attempted to determine the range of facial expressive cues that preterms may be emitting or the possible physiological basis for this behavior. In an attempt to investigate these questions, preterm and term infants were observed in a face-to-face situation. Prior to the session, three minutes of resting EKG was recorded. The infant's facial behavior was coded with a discrete facial action coding system. Maternal behavior was also coded. Measures of heart rate as well as short and long term variability were computed. Results revealed no differences in facial lability or in facial expressiveness between term and preterm infant. In addition, there were no differences in maternal behavior to either term or preterm. There were, however, reliable contingent relationships between facial expression of the infant and maternal behavior. In addition, there was a significant association between short term variability (vagal tone) and infant facial behavior.     

Joint attention in term and preterm infants at 12 months corrected age: the significance of gender and intervention based on a randomized controlled trial

This study tested the effects of optimized neonatal mother–infant transactions on joint attention performance at 12 months. Surviving infants <2000 g from a geographically defined area were randomly assigned to a preterm intervention (n = 71) or preterm control group (n = 69). Comparisons were made between preterm groups, secondary with a term group (n = 75). Joint attention was measured using the Early Social Communication Scales. Preterm intervention infants scored significantly higher than preterm control infants on elements Initiating Joint Attention (p < 0.05), Initiating Object Requests (p < 0.05), and Responding to Social Interaction (p < 0.0005). Intervention was not associated with performance on elements Responding to Joint Attention, or on Responding to Requests. ELBW infants scored significantly lower than VLBW and LBW infants on imperative functions. Girls outperformed boys on all communication elements. An intervention implemented during the neonatal period can be of advantage for certain aspects of joint attention performance in preterm infants.     

Maternal perceptions of the sleep patterns of premature infants at seven months corrected age compared to full-term infants

It has been reported that 83%–87% of full-term infants regularly sleep through the night (from midnight to 5 a.m.) by 6 months of age, but there is little information about the sleep patterns of premature infants. The purpose of the current study was to identify maternal perceptions of the sleep patterns of premature infants. Parents of 32 premature infants with birth weight below 1,750 gm and of 13 full-term infants completed a 24-hour sleep record in 30-minute epochs for 1 week at 7 months of chronological (term) or corrected age (premature). Mean birth weight of premature infants was 1,278 ± 340 gm, with a gestational age of 30.4 ± 2.7 weeks. The daily total sleep time, longest sleep segment, frequency of sleep-wake transitions, and percentage of night sleep (8 p.m.–8 a.m.), averaged from the 1-week sleep record and number of night wakenings per week, were used as indicators of sleep patterns. The longest reported sleep segments of premature infants were significantly shorter than those of full-term infants (8.2 ± 2 hours versus 9.6 ± 1 hour, p < 0.01) and the number of night wakenings per week was significantly greater (3.13 ± 3 versus 0.54 ± 7, p < 0.005). Total reported sleep time, percentage of night sleep, and sleep-wake transitions did not differ significantly between premature and full-term infants. However, analysis of feeding events revealed that premature infants received significantly more feedings between midnight and 5 a.m. (M = 0.31 + 3 versus M = 0.06 + 1, p < 0.001). We conclude that sleep pattern diaries kept by parents indicate that premature infants have developed a diurnal sleep rhythm by 7 months corrected age, but they still have shorter sleep segments and they awaken more during the night than term infants.     

Early receptive and productive language skills in preterm and full-term 8-month-old infants

Early receptive and productive language skills were examined for preterm low birthweight infants and full-term normal birthweight infants from middle-class homes. Nineteen preterm infants and 19 full-term infants were observed in a laboratory setting at the gestationally corrected age of 8 months. To avoid the frequent confound between prematurity and low socioeconomic status, mothers of the two groups of infants were matched on educational levels. Regression analyses were used to assess the relative influence of infant cognitive skills, infant sociability, infant birth status, and the mothers' language input as possible predictors of infant receptive language and vocal behavior. Receptive language skills were associated with higher cognitive performance, greater sociability, and preterm birth. Productive language skills were associated with higher cognitive performance. On the basis of this research, the prognosis for language development in preterm infants raised in middle-class homes appears to be excellent.This research was aided by Social and Behavioral Sciences Research grant No. 12-11 from the March of Dimes Birth Defects Foundation and supported by DHHS Grant HD03352. Computing was provided by the Waisman Center Computing Facility at the University of Wisconsin-Madison. Donna Boylan, Sue DaPra, Maria Kleczewski, Michal Rubin, Susan Silverber, and Paula VanLaanan assisted with data collection.     

Processing speed in the 1st year of life: a longitudinal study of preterm and full-term infants

Processing speed was assessed at 5, 7, and 12 months in full-term and preterm infants (birth-weight < 1,750 g). Speed was gauged directly in a new task by presenting infants with a series of paired faces, one that remained the same across trials and one that changed; trials continued until infants showed a consistent novelty preference. At all ages, preterms required about 20% more trials and 30% more time than full-terms to reach criterion. Among preterms, slower processing was associated with greater medical risk (e.g., respiratory distress syndrome). Developmental trajectories for speed (and attention) were similar for both groups. Thus, the deficits in processing speed previously found for preterms in childhood are already present in the 1st year of life.     

Representational momentum in children born preterm and at term

The term representational momentum (RM) refers to the idea that our memory representations for moving objects incorporate information about movement – a fact that can lead us to make errors when judging an object’s location (the RM effect). In this study, we explored the RM effect in a sample of children born very prematurely and a sample born at term. Because preterm children are known to be at risk for problems with motion perception, we anticipated that they would show a weaker or absent RM effect. This prediction was confirmed. In addition, we found that, in both samples of children, 5–6 year olds showed a reduced RM effect compared to 7–9 year olds. These results demonstrate that the ability to represent motion information in memory shows continued development over this age range, and may help to elucidate factors contributing to problems with fine and gross motor planning and execution that have been observed in the preterm population. We propose that problems affecting the formation, maintenance, or use of predictive models, or motion extrapolation skills, may have cascading effects on the development of other abilities.     

The efficacy of massage on short and long term outcomes in preterm infants

Purpose

Premature infants lack the tactile stimulation they would have otherwise experienced in the womb. Infant massage is a developmentally supportive intervention that has been documented for several decades to have a positive effect on both full term and preterm infants. The purpose of this study was to assess the short and long term benefits of massage on stable preterm infants.

Methods

A quasi experimental design was used, 66 infants were recruited from two university hospitals with tertiary level NICUs; 32 infants received the massage therapy by their mothers. Data collection by a researcher blind to the infants’ group assignments included weight at discharge, pain responses on the PIPP scale at discharge, length of stay in hospital, neuro-developmental outcome (Bayley scores) and breastfeeding duration at 12 months corrected age.

Results

Infants who were massaged had significantly lower scores on the PIPP after a heel-stick compared to before the massage and had lower PIPP scores at discharge compared to the control group. Massaged infants had higher cognitive scores at 12 months corrected age. Weight gain, length of stay, breastfeeding duration and motor scores did not differ between groups.

Conclusion

Stable preterm infants benefit from massage therapy given by their mothers and may be a culturally acceptable form of intervention to improve the outcomes of preterm infants.     

Attention and recognition memory in the 1st year of life: a longitudinal study of preterm and full-term infants

Several aspects of visual attention and their implications for recognition memory were examined in a longitudinal sample of full-term and preterm (birth weight < 1,750 g) infants seen at 5, 7, and 12 months of age. At all 3 ages, full-terms had shorter look durations, faster shift rates, less off-task behavior, and higher novelty scores than preterms. Both groups followed similar developmental trajectories, with older infants having shorter looks and more shifts. Infants were consistent in attentional style across problems of the same type, across problems that used different types of stimuli (faces and patterns), and across the familiarization and test phases of this paired-comparison design; there was also modest cross-age stability. Shorter looks and higher shift rates during familiarization were related to better recognition memory, with shift rate adding to prediction independently of either peak or mean look. These findings underscore the importance of attention to infant information processing.     

Maternal and paternal infant representations: A comparison between parents of term and preterm infants

Objective

Research on parental attachment representations after preterm birth is limited and inconclusive. The present study is the first in which maternal and paternal attachment representations after term, moderately and very preterm birth are compared. In addition, special attention was directed toward disrupted attachment representations.

Method

Mothers and fathers of term infants (≥37 weeks of gestational age, n = 71), moderately preterm infants (≥32–37 weeks of gestational age, n = 62) and very preterm infants (<32 weeks of gestational age, n = 56) participated in the present study. Attachment representations (balanced, disengaged, distorted) about their infants were evaluated with the Working Model of the Child Interview (WMCI). To asses disrupted representations the coding of the WMCI was extended with the disrupted scale (WMCI-D).

Results

The three main classifications of attachment representations were not affected by preterm birth. In addition, there were no gender differences in the rate of balanced representations. In case of non-balanced representations however, maternal representations were more often distorted, whereas fathers showed more often disengaged representations. Results further revealed that maternal disrupted attachment representations were marked by role/boundary confusion or disorientation, whereas paternal disrupted attachment representations were characterized by withdrawal.

Conclusion

Given the gender differences it is essential to tailor interventions according to the attachment representations of the parent, in order to be able to alter their non-balanced and/or disrupted attachment representations.