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.     

Hot executive function following moderate‐to‐late preterm birth: altered delay discounting at 4 years of age

Interest in monitoring long‐term neurodevelopmental outcomes of children born moderate‐to‐late preterm (32–36 weeks gestation) is increasing. Moderate‐to‐late preterm birth has a negative impact on academic achievement, which may relate to differential development of executive function (EF). Prior studies reporting deficits in EF in preterm children have almost exclusively assessed EF in affectively neutral contexts in high‐risk preterm children (< 32 weeks gestation). Disrupted function in motivational or emotionally charged contexts (hot EF) following preterm birth remains uninvestigated, despite evidence that preterm children show differential development of neural circuitry subserving hot EF, including reduced orbitofrontal cortex volume. The present study is the first to examine whether low‐risk, healthy children born moderate‐to‐late preterm exhibit impairments in the development of hot EF. Preterm children at age 4.5 years were less likely to choose larger, delayed rewards across all levels of reward magnitude on a delay discounting task using tangible rewards, but performed more similarly to their full‐term peers on a delay aversion task involving abstract rewards and on measures of cool EF. The relationship between gestational age at birth and selection of delayed rewards extended across the entire gestational age range of the sample (32–42 weeks), and remained significant after controlling for intelligence and processing speed. Results imply that there is not a finite cut‐off point at which children are spared from potential long‐term neurodevelopmental effects of PT birth. Further investigation of reward processing and hot EF in individuals with a history of PT birth is warranted given the susceptibility of prefrontal cortex development to early environmental variations.     

Sucking patterns are not predictive of further feeding development in healthy preterm infants

Preterm infants are at risk of experiencing difficulties in their feeding development. For a possible early identification of these, we examined the association between sucking patterns, assisted spoon feeding, and chewing skills in 40 healthy preterm infants, and the role of experience in the acquisition of these skills in a prospective longitudinal study. Sucking patterns were evaluated at 34, 37, and 44 weeks postmenstrual age (PMA), assisted spoon feeding was evaluated at 6, 9, and 12 months PMA, and chewing was evaluated at 9, 12, and 24 months PMA. Sucking patterns were rated using the Neonatal Oral Motor Assessment Scale, assisted spoon feeding was rated using the Observation List Spoon Feeding, and chewing was evaluated using the Mastication Observation and Evaluation Instrument.All infants showed progression in their oral motor skills during the study period, but not all demonstrated a stable progression of skills. Quality of sucking patterns was not associated with skill level achievement of assisted spoon feeding or with chewing. Length of experience in sucking was significantly associated with duration of supplemental tube feeding but not with the quality of the sucking pattern. Length of chewing experience was significantly associated with chewing abilities at 9 and 12 months PMA. No clinical characteristics were sufficiently predictive of oral motor skill development. Results show that sucking patterns are not predictive of subsequent feeding development in healthy preterm infants. The food consistency offered and the length of feeding experience influenced the acquisition and quality of oral motor skills differently.     

Developmental changes in the responses of preterm infants to a painful stressor

The purpose of this investigation was to examine longitudinally gestational age and developmental differences in preterm infants' self-regulatory abilities in response to a painful stressor, as well as associations between behavioral and cardiovascular responses. Participants included 49 healthy premature infants. Behavioral and cardiovascular responses to a heel stick blood draw were compared between infants of 28-31 and 32-34 weeks' gestation age at birth. Both gestational age groups displayed behavioral and cardiovascular indications of stress in response to the blood draw. However, both shortly after birth and several weeks later, infants born at younger gestational ages (28-31 weeks) were more physiologically reactive. Evidence that the behavioral stress responses of 28-31 weeks' gestation age group preterm infants do not reflect their physiological responses suggests that evaluation of preterm infants' experiences and risk require assessments of both physiology and behavior. The greater stress vulnerability of the 28-31 weeks' gestation group relative to the 32-34 weeks' gestation group and the implications of this for subsequent development are discussed.     

Preference for infant-directed speech in preterm infants

The current study explores the effects of exposure to maternal voice on infant sucking in preterm infants. Twenty-four preterm infants averaging 35 weeks gestational age were divided randomly into two groups. A contingency between high-amplitude sucking and presentation of maternal voice was instituted for one group while the other group served as a yoked control. No significant differences were observed in sucking of the two groups, but the degree of pitch modulation of the maternal voice predicted an increase in the rate of infant sucking.     

The effect of preterm birth on infant negative affect and maternal postpartum depressive symptoms: A preliminary examination in an underrepresented minority sample

ObjectiveTo examine the effect of preterm birth on maternal postpartum depressive symptoms and infant negative affect in an underrepresented minority sample.MethodParticipants were 102 mothers and their 3- to 10-month-old infants. Mothers completed the Edinburgh Postnatal Depression Scale and the Infant Behavior Questionnaire-Revised.ResultsRelative to normative samples, the current underrepresented minority sample of mostly Hispanics and Blacks displayed high rates of preterm birth (30%) and maternal postpartum depressive symptoms (17%). Preterm birth had a significant direct effect on postpartum depressive symptoms and infant negative affect. Additionally, there was an indirect effect of postpartum depressive symptoms on the relation between preterm birth and infant negative affect. Specifically, lower birth weight and gestational age predicted higher levels of depressive symptoms in the mother, and higher levels of depressive symptoms in the mother, in turn, predicted higher levels of infant negative affect.ConclusionFindings emphasize the importance of screening for postpartum depressive symptoms and infant negative affect among mothers and their preterm infants, especially among families from underrepresented minority backgrounds.     

Differential maturation of fetal responses to vibroacoustic stimulation in a high risk population

Maturation of human fetal response to vibroacoustic stimulation was examined in 163 high risk fetuses from 23 to 36 weeks gestational age (GA). Each fetus received three vibroacoustic trials and three no-stimulus control trials (randomly assigned) while fetal heart rate (FHR) was recorded and body movement was observed on ultrasound scan. For data analyses, fetuses were categorized into preterm compromised (n = 57), preterm healthy (n = 42) and term healthy (n = 64) based on evidence of compromise at birth. Differential maturation was observed among the outcome groups. The term healthy group exhibited a body movement and, on the first stimulus trial, an FHR deceleration response at 27 weeks GA with a shift to an FHR acceleration response at 30 weeks GA. By 33 weeks GA, responding was indistinguishable from that reported for low risk fetuses with response rates of 92% for both movements and FHR accelerations. The preterm healthy outcome group showed a body movement and an FHR acceleration response at 27 weeks GA. Over gestation, there was no maturation of either response. The preterm compromised outcome group showed a body movement response at 24 weeks GA which did not mature. An FHR acceleration response was elicited at 27 weeks GA with the magnitude of the acceleration increasing over gestation; at 33 weeks GA the magnitude was below that observed in the term healthy group. With advancing gestation, the rate of cardiac–movement coupling increased only in the two healthy outcome groups. It was concluded that differential fetal behaviour as a function of fetal/newborn outcome may reflect differential functional development of the fetal nervous system.     

Maternal ratings of infant regulatory competence from 6 to 12 months: influence of perceived stress, birth-weight, and intervention: a randomized controlled trial

Mothers’ reports of preterm and term infants’ temperament from 6 to 12 months of age were studied, with intervention and stress as predictors. Preterm infants with a birth weight <2000 g were randomized to an intervention (71) or a control (69) group. A control group of healthy term infants (74) was also established. The intervention was a modified version of the “Mother–Infant Transaction Program”, aimed at sensitizing caregivers to the infants’ individual characteristics. Temperament was measured with the Infant Behavior Questionnaire, and stress with the Parenting Stress Index. There were no group differences in temperament at 6 or 12 months or in change during the same period. There was a strong association between stress and negative reactivity in the preterm control group at 12 months. In the preterm intervention group, there were strong negative correlations between stress and regulatory competence at 6 months. The intervention seemed to change the relationship between stress and temperament. The strength of this association indicates that the intervention sensitized mothers to the temperamental regulatory competence of their preterm infants.     

The relationship of perinatal birth status to handedness: A prospective study

As part of a longitudinal study of the consequences of high risk birth, 66 infants born to right-handed parents were given two unimanual tasks at 24 months of age to assess their hand preference. The 66 infants had been assigned to one of four diagnostic categories at birth: Premature with no postnatal medical complications; premature and having experienced respiratory distress; term and having experienced birth asphyxia during labor and delivery; term with normal delivery and postnatal course. Results of the handedness tasks revealed an increased incidence of use of the left hand among the term infants who underwent birth asphyxia and among the healthy preterm infants. The data indicate that timing of birth stress may play an important role in the ontogeny of pathological left-handedness.     

EFFECTS OF KANGAROO MOTHER CARE ON MATERNAL MOOD AND INTERACTION PATTERNS BETWEEN PARENTS AND THEIR PRETERM,LOW BIRTH WEIGHT INFANTS: A SYSTEMATIC REVIEW

The birth of a premature infant can have adverse effects on the mood of mothers and on the interaction patterns between parents and their preterm babies. The aim of the present systematic review was to examine whether the Kangaroo Mother Care (KMC) intervention can attenuate these adverse psychological effects of a premature birth by ameliorating negative maternal mood and/or promoting more positive interactions between preterm infants and their parents. The results showed that although findings of studies were inconclusive, there is some evidence to suggest that KMC can make a positive difference on these areas. Specifically, it was found that KMC can improve negative maternal mood (e.g., anxiety or depression) and promote more positive parent–child interactions. Limitations and directions for future research are discussed.     

Relatedness and Individuation Among Young Adults Born Preterm: The Role of Relationships with Parents and Death Anxiety

Preterm birth may constitute a risk factor for long-term difficulties when facing developmental tasks of relatedness and individuation in young adulthood. Since these early experiences might leave individuals more susceptible to anxiety, we examined whether relationships with parents and death anxiety mediated the associations between preterm birth and difficulties in relatedness and individuation. The sample included 57 emerging adults who were born preterm, and a paired control group that filled out questionnaires: The Perceptions of Adult Attachment Questionnaire, Personal Assessment of Intimacy in Relationships, the death anxiety test, and projective assessment of death anxiety. Preterm young adults and their counterparts exhibited similar levels of closeness with their parents, with romantic partner, and with best friend. A different picture emerged with regard to differentiation and death anxiety. Preterm young adults exhibited higher levels of emotional reactivity and fusion with others, and higher levels of death anxiety than their counterparts. Death anxiety mediated the relations between preterm birth status and differentiation. It appears that, despite the fact that these youngsters experienced a traumatic event early in their lives, they overcame this difficult experience and were successful in maintaining closeness with close others. In contrast, the traces of the preterm birth might be more pronounced in the domain of differentiation. People who experienced separations from significant others, especially early in life, may develop high levels of death anxiety as death is experienced as the ultimate separation from a close person. Enduring death anxiety might complicate the individuation process. Gender differences that were found are in accord with previous findings. The strengths and limitations of the study as well as suggestions for future research are discussed.     

Pregnancy-specific stress, prenatal health behaviors, and birth outcomes

OBJECTIVE: Stress in pregnancy predicts earlier birth and lower birth weight. The authors investigated whether pregnancy-specific stress contributes uniquely to birth outcomes compared with general stress, and whether prenatal health behaviors explain this association. DESIGN: Three structured prenatal interviews (N = 279) assessing state anxiety, perceived stress, life events, pregnancy-specific stress, and health behaviors. MAIN OUTCOME MEASURES: Gestational age at delivery, birth weight, preterm delivery (<37 weeks), and low birth weight (<2,500 g). RESULTS: A latent pregnancy-specific stress factor predicted birth outcomes better than latent factors representing state anxiety, perceived stress, or life event stress, and than a latent factor constructed from all stress measures. Controlling for obstetric risk, pregnancy-specific stress was associated with smoking, caffeine consumption, and unhealthy eating, and inversely associated with healthy eating, vitamin use, exercise, and gestational age at delivery. Cigarette smoking predicted lower birth weight. Clinically-defined birth outcomes were predicted by cigarette smoking and pregnancy-specific stress. CONCLUSION: Pregnancy-specific stress contributed directly to preterm delivery and indirectly to low birth weight through its association with smoking. Pregnancy-specific stress may be a more powerful contributor to birth outcomes than general stress.     

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.     

Preterm birth affects dorsal-stream functioning even after age 6

With increasing numbers of preterm infants surviving, the impact of preterm birth on later cognitive development presents a major interest. This study investigates the impact of preterm birth on later dorsal- and ventral-stream functioning. An atypical pattern of performance was found for preterm children relative to full-term controls, but in the dorsal-drawing task only. These findings suggest that the number of gestational weeks does affect dorsal-stream functioning, even after more than 6 years of favorable environmental conditions in healthy preterm children.     

Reinforcement from the sucking environment and subsequent modification of sucking behavior in the human neonate

The reinforcing aspects of sucking behavior in 36 human newborns was examined in a limited instrumental conditioning paradigm where sucking was both operant and reinforcer. During training, response density (rate based on sucking opportunity time) and latency were measures of two components of nonnutritive sucking, contingent negative pressure suction, and incidental jaw movement. The strategy for determining the reinforcing aspects of sucking involved comparisons of three types of sucking stimuli as reinforcers. The nature of modified operant sucking was investigated during extinction by examining number of sucks per burst, number of bursts emitted, and interburst interval time. The feedback from sucking which acted as reinforcement was concluded to be response density. Sucking was modified by changes in pausing behavior, including response latency and pauses between bursts of sucks. The number of sucks per burst also showed a significant change under certain conditioning arrangements.     

Observers' reactions to genetic testing: the role of hindsight bias and judgements of responsibility

In 3 studies, we examined the effect of birth outcome on observers' reactions to genetic testing. Participants read a scenario in which a woman declined to take a genetic screening test and subsequently gave birth to a child with a genetic disorder (negative outcome) or a healthy child (positive outcome). Retrospective judgments of the likelihood that the child would have a genetic disorder were higher given negative than positive outcome knowledge under conditions of high genetic risk. Moreover, the more likely a negative outcome was perceived to be, the more responsible the mother was held for not taking the genetic screening test. Consistent with Weiner's (1993) theory, responsibility judgments were linked to displeasure and sympathy, with sympathy in turn being related to help judgments.     

Phonetic discrimination ability of a native vowel contrast in preterm infants

Preterm birth is considered a risk factor for cognitive and linguistic development; however, research focusing on the comparison between preterm and full term infants' early abilities in speech perception is still scarce. In this study, the ability to perceive and discriminate a native vowel contrast by a sample of preterm infants at 4 and 8 months of age (corrected for gestation) has been analyzed using the familiarization-preference procedure and complex stimuli (CV.CV, multispeakers). Results reveal differences at 4 months of age between pre-term and control groups; only the latter successfully categorize and react to the vowel change. By 8 months of age, preterm infants are able to solve the task. A positive correlation was observed between duration of attention (visual fixation measures) and a number of neonatal risk factors. Results show the effects of preterm birth on the processing of complex stimuli and suggest the need to further explore the connection between early speech perception capacities and language development in this at-risk population.     

Stability of developmental status and risk of impairment at 24 and 36 months in late preterm infants

BackgroundFew studies investigated whether late preterm infants might have developmental delays in several domains in early life and how stable the lag in developmental status might be.AimWe aimed to examine the stability of potential delays across developmental domains at 24 and 36 months of age in late preterm (34°-36⁶ weeks) and term (≥37 weeks) children and whether the risk of delays remained high at 36 months.Study design, subjects, and outcome measureWe conducted a prospective cohort analysis of the children of pregnant women participating in the Vitamin Antenatal Asthma Reduction Trial (VDAART). 652 children who were prospectively followed up and had parent-completed Ages Stages Questionnaires (ASQ-3) questionnaires at both 24 and 36 months were analyzed to assess their domain-specific developmental status.Results6.61 % (42/635) of children had a late preterm birth. Developmental delays were stable between 24 and 36 months on all 5 domains for the children born preterm and on 4/5 domains for those born at term. The developmental domains with the status stability at 24 and 36 months in both late preterm and term children were the gross motor, communication, personal-social skills, and problem-solving. Late preterm children compared with term children remained at higher risk of delays at 36 months for gross motor, communication, and problem-solving skills (aOR = 4.54, 95 %CI: 1.81−10.79; aOR = 8.60, 95 %CI: 3.10−23.28 and aOR = 3.80, 95 %CI: 1.58−8.73, respectively).ConclusionLate preterm birth is associated with suboptimal development and stability in several domains at both 24 and 36 months and compared with term birth, requiring early monitoring and assessment of the developmental lag to avoid potential long-term implications.     

Late Preterm Birth: A Review of Medical and Neuropsychological Childhood Outcomes

Late preterm (LP) birth (34 0/7 - 36 6/7 weeks?? gestation) accounts for nearly three-fourths of all preterm births, making this population a sizeable public health concern. The immature fetal development associated with LP delivery increases the risk of mortality and short-term medical complications. Which combination of maternal, fetal, or neonatal risk factors may be most critical has only recently begun to be addressed, and whether LP birth??s disruptive impact on brain development will exert adverse effects on neuropsychological functioning in childhood and adolescence has been understudied. Early data have shown a graded response, with LP children often functioning better than very preterm children but worse than term children, and with subtle intellectual and neuropsychological deficits in LP children compared with healthy children born at term gestational age. Further characterization of the neuropsychological profile is required and would be best accomplished through prospective longitudinal studies. Moreover, since moderate and LP births result in disparate medical and psychological outcomes, the common methodology of combining these participants into a single research cohort to assess risk and outcome should be reconsidered. The rapidly growing LP outcomes literature reinforces a critical principle: fetal development occurs along a dynamic maturational continuum from conception to birth, with each successive gestational day likely to improve overall outcome.