Macropremies: underprivileged newborns

Ethical reflections on organizing the first human trial of artificial womb technologies

OBJECTIVE

To investigate how to protect participants in the artificial womb technology (AWT) human trials.

METHOD

We compared randomized controlled trials and single arm trials to understand which trial design best balances the interests of science and participants. We also compared AWT trials with comparable settings to understand how to protect participants.

RESULTS

Randomized trials might fail in reaching a sizeable sample, which could pointlessly expose participants to risks. Furthermore, parents who choose to participate in the trial might expect to receive AWT. Failed expectations might distress parents and hinder the therapeutic relationship. The trial is divided into two steps. First, delivery into AWT involves two participants: the mother and the fetus. As AWT requires a C-section, the procedure cannot be carried out without the mother's consent regardless of fetal benefit. Treatment in AWT, involves one participant: the infant. As for any other invasive intervention, the AWT trial should be suspended if harmful.

CONCLUSIONS

A single arm trial could prevent some of the methodological and ethical challenges of the randomized trials. Moreover, better decisional tools should be developed to help parents decide whether to participate in the AWT trial. For example, using visual aids or showing the AWT.

Psychosocial functioning in adolescents: results according to Amiel-Tison neurological assessment in a group of preterm infants

OBJECTIVE

This prospective study investigated the relationship between Amiel-Tison neurological assessment (ATNA) in preterm children and their psychosocial functioning in adolescence.

METHODS

From the initial group of 45 children regularly assessed by the ATNA from term until the age of 2 years, 27 participated in the follow-up at 13 years.

RESULTS

Of the three groups categorized by neurological signs as normal, intermediate or abnormal, parents of adolescents with normal ATNA reported the lowest number of executive function problems (p = 0.019) and behavioral symptoms (p = 0.011), while the adolescents themselves reported the lowest number of behavioral symptoms (p = 0.005) and the highest quality of life (p = 0.012). The number of problems reported increased with the number of abnormal neurological signs.

CONCLUSION

Standardized neurological assessment may be a helpful clinical tool for the identification of children at risk for later psychosocial problems who could benefit from prevention and early intervention programs.

Preterm-infant emotion regulation during the still-face interaction

Very-preterm (VPT), moderately-preterm (MPT), and full-term (FT) infants' emotion-regulation behaviors were assessed via the Still-Face procedure at a corrected age of four months. As a developmental task during the first year of life, emotion regulation is important for social and cognitive development. Although substantial evidence indicates that VPT infants exhibit emotion-regulation difficulties, little is known about MPT infants' emotion regulation capabilities, this group also possibly being at risk. The participants included 135 parent-infant dyads: 46 VPT (gestational age 24-32 weeks), 51 MPT (gestational age 32-34 weeks), and 38 FT (gestational age 37-41 weeks). The infants' affect, gaze-aversion, and self-comforting behaviors were coded. Preterm infants responded to parental still face in similar fashion to FT infants, displaying robust still-face and recovery effects. The preterm infants exhibited less developed emotion-regulation behaviors, however, manifested in less positive affect and more gaze aversion in the face-to-face and reunion episodes compared to FT infants. With respect to self-comforting behaviors, each group displayed a significantly different pattern of behaviors throughout the procedure, suggesting better emotion regulation skills among MPT infants compared to the VPT infants. The findings on gaze aversion and self-comforting behaviors could have implications for strategies to incorporate into intervention programs supporting development of emotion regulation skills.

Macro preemies: no thresholds for risks or concerns

PURPOSE OF REVIEW

To provide an overview of the literature regarding medical and developmental risks for moderate to late preterm infants (32-36 weeks gestation), with particular attention to the pediatrician's role in care during both inpatient and outpatient periods.

RECENT FINDINGS

Although the risks of medical issues and developmental delays decrease with increasing gestational age, research suggests that infants born after 32 weeks' gestation often exhibit significant morbidities associated with prematurity. These infants, often referred to as 'macro preemies', have been found to be at a greater risk for medical complications secondary to immature organ systems including impairments in temperature regulation, respiratory functioning, feeding coordination, bilirubin excretion, glucose control, and infection susceptibility. Recent studies of macro preemies also suggest a higher incidence of significant deficits noted in gross and fine motor skills, speech and communication, and learning and behavior compared to their full-term counterparts. Without careful attention from birth, macro preemie infants could be susceptible to both medical issues and developmental delays.

SUMMARY

Physicians should be aware of the research regarding increased medical and developmental risks for all infants born before term in order to provide their patients with comprehensive medical and neurodevelopmental follow-up care.

Relationship between neurological assessments of preterm infants in the first 2 years and cognitive outcome at school age

BACKGROUND

The risk of cognitive disability in preterm infants is higher than in general population. The Amiel-Tison neurological assessment could be a useful tool for early identification of preterm children at risk of cognitive disability in school age. This study investigated the value of categorization of neurological signs assessed by the Amiel-Tison neurological assessment in the first 2 years of life in relation to cognitive performance at school age in a group of preterm children.

METHODS

Preterm children with gestational age from 23 to 36 weeks were included in the prospective study. From the initial group of 45 children, in whom the Amiel-Tison neurological assessment was performed at term age, at 3 months corrected age, and at 2 years, the Wechsler Intelligence Scale for Children-third edition was performed in 39 children after school entry.

RESULTS

Full scale IQ, Verbal IQ, and Performance IQ of the whole group of preterm children were not significantly different from the normative data; most of the children had IQ scores in the normal range (≥85). The mean cognitive results of children decreased as the number of neurological signs increased. There was a significant correlation between the categories of neurological signs at 2 years and later cognitive results.

CONCLUSIONS

The grade of severity of neurological signs at 2 years was associated with the cognitive results at school age. The categorization of neurological signs according to the Amiel-Tison neurological assessment in preterm children might have prognostic value for cognitive outcome at school age.

Neurodevelopmental outcomes of infants born prematurely

Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

Neuropathologic studies of the encephalopathy of prematurity in the late preterm infant

It has been widely suggested that brain damage in survivors of late preterm deliveries is similar to that in early preterm infants, only less severe. This report addresses this concept through reanalysis of published neuropathologic data obtained according to late preterm in comparison with early preterm ages. Findings suggest that the spectrum of brain injury in the late preterm infant, as determined in an autopsy population, is similar to that found in early preterm infants, with potential differential susceptibility for different neuronal, glial, and vascular indices. Further research is needed to more clearly define developmental cellular susceptibilities in preterm populations.

Safe discharge of the late preterm infant

Late preterm infants are infants who are premature, but often mature enough to be managed in settings and with treatment plans appropriate for term newborns. They are arbitrarily defined as infants born at gestational ages of 34, 35 and 36 weeks. Late preterm infants have more problems with adaptation than term infants, and may require neonatal intensive care and prolonged admission. However, those who do not may, appropriately, be triaged to mother-baby care in a low-risk nursery setting. Special attention must be offered to the late preterm infant in ensuring adequate thermal homeostasis and the establishment of successful feeding before discharge. In particular, care must be taken to ensure that these babies do not experience severe late hyperbilirubinemia, which characteristically occurs in the breastfeeding late preterm infant at four to five days of age and is not always predictable by routine bilirubin screening before 48 h of age. Discharge of a late preterm infant places particular demands on the community; accessible facilities for retesting, re-evaluation and readmission must be made available by the discharging institution.

Clinical issues in the management of late preterm infants

Prematurity is defined as birth before 37 weeks of gestation and is the major determinant of morbidity and mortality in newborns. The gestational ages known as near term or late preterm represent about 75% of preterm births and are the fastest growing subgroups of premature infants. These infants range in gestational age from 34 0/7 to 36 6/7 weeks and are at greater risk of morbidity, such as respiratory complications, temperature instability, hypoglycemia, kernicterus, feeding problems, neonatal intensive care unit admissions, and adverse neurological sequelae when compared with term infants. Long-term neurological and school-age outcomes of late preterm infants are concerns of major public health importance because even a minor increase in the rate of neurological disability and scholastic failure in this group can have a huge impact on the health care and educational systems. There is an urgent need to educate health care providers and parents about the vulnerability of late preterm infants, who are in need of diligent monitoring and care during the initial hospital stay and a comprehensive follow-up plan for post neonatal and long-term evaluations. Clinicians involved in the day-to-day care of late preterm infants, as well as those developing guidelines and recommendations, would benefit from having a clear understanding of the potential differences in risks faced by these infants, compared with their more mature counterparts.

Complications of the late preterm infant

One of the goals of Healthy People 2010 (set in 1998) was to reduce preterm birthrates from 11.6% to 7.6%. However, in 2004, the preterm birthrate of 12.5% was actually higher than the rate in 1998. Approximately 65% of this increase in prematurity rate is attributed to the increasing birthrate of the late preterm infant. Care of the late preterm infant is far more complicated than many hospital policies and clinical guidelines imply. It cannot be stressed enough to frontline clinicians that late preterm infants are not full-term infants. Their care should not be defined by the same policies and practices that govern term infants. The purpose of this article is to explore the complications that accompany late preterm birth. The following complications will be discussed: thermoregulation challenges, feeding difficulty, late neonatal sepsis, prolonged physiologic jaundice, hypoglycemia, possible neurodevelopmental differences, and respiratory problems.

A decade comparison of preterm motor performance at age 4

This was a prospective longitudinal study of two cohorts comprised of one full term and three premature infant groups born 10 years apart. Birth cohort, perinatal morbidity, and birth weight effects were investigated at age 4. Cohort 1 (1985-1989) had longer gestation, higher birth weight, and better Apgar scores than Cohort 2 (1996-1999), which had more intraventricular hemorrhage and bronchopulmonary dysplasia. Cohort and perinatal morbidity group, but not birth weight, predicted motor scores. Preterm Cohort 2 children had better oral motor, fine motor, and total motor scores, but lower visual motor integration scores than Cohort 1. Motor problems continue to affect preterm children at age 4, in particular those who experience perinatal morbidity, despite a decade of neonatal intensive care advancements.

Neonatal and 5-Year Outcomes After Birth at 30–34 Weeks of Gestation

OBJECTIVE

To evaluate the rates of in-hospital death, neonatal complications, and 5-year outcomes of infants born at 30-34 weeks of gestation.

METHODS

In nine regions of France, all 2,020 stillbirths and live births at 30, 31, and 32 weeks in 1997 and all 457 births at 33 and 34 weeks in April and October 1997 were recorded. Survivors were evaluated at 5 years of age.

RESULTS

Increasing gestational age from 30 to 34 weeks was associated with progressive decreases in in-hospital mortality (from 8.1% to 0.4%) and neonatal complications (respiratory distress syndrome, 43.8% to 2.6%; maternofetal infections, 7.2% to 2.6%; and severe white matter injury, 5.5% to 1.3%). Although infants at 33 and 34 weeks of gestation rarely experienced necrotizing enterocolitis, bronchopulmonary dysplasia, or nosocomial infections, they still required endotracheal ventilation, antibiotics, or parenteral nutrition. At 5 years of age, older gestational age was associated with significant decreases in rates of cerebral palsy (6.3% at 30 weeks and 0.7% at 34 weeks) and mild to severe cognitive impairments (35.3% at 30 weeks and 23.9% at 34 weeks). In singletons, preterm rupture of membranes or preterm labor carried an increased risk of cerebral palsy but not of cognitive impairment.

CONCLUSION

Neonates born at 30-34 weeks experienced substantial morbidity and often required admission to neonatal intensive care units. These outcomes suggest that prolonging pregnancies beyond 34 weeks may be desirable whenever possible. Infants born at 30-34 weeks should be carefully monitored to ensure prompt detection and management of neurodevelopmental impairment.

Caregiver-reported health outcomes of preschool children born at 28 to 32 weeks' gestation

OBJECTIVE

We conducted a population-based survey of caregivers of all preschoolers at 42 months of age who had been admitted at birth in 1996-1997 to a tertiary neonatal intensive care unit in British Columbia (BC), Canada.

METHODS

In this paper, we examine health status (measured by Health Status Classification System [HSCS-PS]), health-related quality of life (HRQL) (measured by Infant and Toddler Quality of Life Questionnaire), and behavioral outcomes (measured by Child Behavior Checklist) of the preschoolers in the sample who were born at 28-32 weeks gestational age (GA) in comparison to those born at <28 weeks GA. In addition, we compare these outcomes to health status, HRQL, and behavioral outcomes of a cohort of healthy full-term infants identified from the primary care practices at two of the hospital sites in BC in 1996-1997.

RESULTS

From the total identified sample of 555 children, the survey was completed for 50 children born at <28 weeks GA, 201 children born at 28-32 weeks GA, and 393 healthy full-term subjects. The developmental outcomes of the preschoolers born at 28-32 weeks GA was very similar to those born at <28 weeks GA. We also found increased parental report of problems related to health status and HRQL among the 28-32 weeks GA group. When compared with the term cohort, the 28-32 weeks GA group had poorer outcomes in all HRQL domains.

CONCLUSION

This study discusses the importance of continued neurodevelopmental follow-up care of infants born at 28-32 weeks GA in addition to those infants born <28 weeks GA.

Is the late preterm infant more vulnerable to gray matter injury than the term infant?

This article addresses the issue of whether the late preterm infant is more susceptible to gray matter injury induced by hypoxia-ischemia than the term infant. Although different gray matter regions display varying patterns of neuronal injury in the face of hypoxia-ischemia during advancing gestational development, little is known about the specific patterns of injury faced by the late preterm infant. This changing pattern of neuronal vulnerability with age likely reflects developmental changes of susceptibility and protective factors essential for responding to energy deprivation at the molecular, cellular, biochemical, and vascular levels. Future research involving closer examination of the late preterm period is essential to provide a greater understanding of the neuronal vulnerability in the face of hypoxic-ischemic injury.

Shorter hospital stay for moderately preterm infants

AIM

To determine length of hospital stay (LOS) for moderately preterm infants during the last 20 years, and to identify factors affecting the number of bed-days.

METHODS

Review of LOS for all infants delivered between 30 to 34 gestational weeks during 1983, 1988, 1993, 1998 and 2002.

EXCLUSION CRITERIA

life-threatening abnormalities, chromosomal anomalies and death during hospitalization.

RESULTS

564 included infants accounted for 20% of admissions and 48% of bed-days in the neonatal unit. Between 1983 and 2002, maternal age and use of nasal continuous positive airway pressure increased, use of antibiotics and mechanical ventilation decreased, whereas distributions for gestational age, birthweight, gender, smallness for gestational age, low Apgar score or incidence of respiratory distress syndrome did not change. For healthy inborn singletons discharged home, LOS decreased from 1983 (28+/-11 d, mean+/-SD values) to 2002 (14+/-7 d, p<0.05). Infants born more immature had longer LOS, but postconceptional age at discharge did not differ between age groups.

CONCLUSION

LOS for moderately preterm infants has decreased as a result of individualized neonatal care and organization of homecare support. Shorter LOS is of benefit to the family, prevents overcrowding in the NICU and has important economic implications.

Are children of moderately low birth weight at increased risk for poor health? A new look at an old question

OBJECTIVE

The goal was to examine whether moderately low birth weight children were at greater risk for health problems than normal birth weight children in a nationally representative sample of US children.

METHODS

Data were analyzed for 7817 children, 0 to 12 years of age, from the sample child file of the 2002 National Health Interview Survey. Logistic regressions were estimated to examine whether morbidity rates were higher among moderately low birth weight children than among normal birth weight children and to control for covariates. Health was measured as having a special health care need, having a chronic condition, being hospitalized in the past year, having a learning disability, attention-deficit disorder/attention-deficit/hyperactivity disorder, or other behavioral disorders, having minor health conditions, and having acute illnesses.

RESULTS

With control for other confounders, moderately low birth weight children were significantly more likely than normal birth weight children to be identified as having a special health care need, having a chronic condition, having a learning disability, and having attention-deficit disorder or attention-deficit/hyperactivity disorder. They were not more likely to have a hospitalization in the past year, other behavioral disorders, or minor health conditions or acute illnesses.

CONCLUSIONS

This population-based study of rates of current morbidity shows that moderately low birth weight children born since 1990 are vulnerable to a wide range of health, learning, and behavioral problems, compared with normal birth weight children. This suggests the need for continued focus on ways to reduce morbidity rates for moderately low birth weight children.

Cold stress and hypoglycemia in the late preterm ("near-term") infant: impact on nursery of admission

Late preterm infants (34-37 weeks gestation) pose unique challenges to physicians and nurses involved in their care after birth. They may be cared for in different units within hospitals after birth, including Neonatal Intensive Care Units, Newborn Nurseries, or rooming in with the mother. As a result of their gestational age and birth weight, the late preterm infant is often assessed quickly and triaged identical to term infants. Such practice can potentially result in a lack of attention to important components for successful transition after birth. Cold stress and hypoglycemia are the two important problems in late preterm infants which require immediate treatment. Thus, surveillance of these and other physiological variables is needed to insure that they do not affect successful adaptation during the early hours and days after birth.

Neurodevelopmental outcomes of infants born prematurely

Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

Assessment of gestational age and neuromaturation

Neuromaturation is the functional development of the central nervous system (CNS). It is by its very nature a dynamic process, a continuous interaction between the genome and first the intrauterine environment, then the extrauterine environment. Understanding neuromaturation and being able to measure it is fundamental to infant neurodevelopmental assessment. Fetal and preterm neuromaturation has become easier to observe with the advent of prenatal ultrasonography and neonatal intensive care units. A number of measures of degree of fetal maturation have been developed and used to estimate gestational age (GA) at birth. The most reliable measures of GA are prenatal measures, especially from the first trimester. Postnatal GA measurements tend to be least accurate at the extremes of gestation, that is, in extremely preterm and post-term infants. Observations of measures of neuromaturation in infants born to mothers with pregnancy complications, including intrauterine growth restriction, multiple gestation, and chronic hypertension, have led to the discovery that stressed pregnancies may accelerate fetal pulmonary and CNS maturation. This acceleration of neuromaturation does not occur before 30 weeks' gestation and has a cost with respect to cognitive limitations manifested in childhood. The ability to measure fetal and preterm neuromaturation provides an assessment of neurodevelopmental progress that can be used to reassure parents or identify at risk infants who would benefit from limited comprehensive follow-up and early intervention services. In addition, measures of neuromaturation have the potential to provide insight into mechanisms of CNS injury and recovery, much-needed early feedback in intervention or treatment trials and a measure of early CNS function for research into the relationships between CNS structure and function.

The Amiel-Tison neurological assessment at term: Conceptual and methodological continuity in the course of follow-up

The Amiel-Tison Neurological Assessment at Term (ATNAT) is part of a set of three different instruments based on a neuro-maturative framework. By sharing a same methodology and a similar scoring system, the use of these three assessments prevents any rupture in the course of high risk children follow-up from 32 weeks post-conception to 6 years of age. The ATNAT which takes 5 minutes to administer may be used in clinical setting as well as in research. Clustering of severe to mild neuro-cranial signs in the neonatal period permits identification of children who could benefit from early intervention.

Neurocognitive outcome after very preterm birth

Premature birth is not normal. Very preterm birth results from major disturbance of pregnancy at a time of rapid growth and development. This review looks at outcomes of premature birth at various stages of life with a view to developing and benchmarking perinatal services.

Special education services and school performance in a regional cohort of low-birthweight infants at age nine

Previous research has shown that low birthweight is a predictor of several adverse educational outcomes, including special educational placement, by middle school age. Most low-birthweight follow-up studies that have extended to school age have focused on very small infants-- < 1500 or < 1000 g; less is known of the school age outcomes for infants with only moderately low birthweight (1500-2000 g). This study examines the prevalence of special educational placement and the relationship of such placement to grade retention, verbal and performance scores on tests of general intelligence, reading and maths achievement scores and classroom hyperactivity among low-birthweight children. In a regional birth cohort of 1105 infants born between 1984 and 1987 and weighing 500-2000 g, 868 children were available for follow-up at age nine. Information on special education placement as well as grade retention, intelligence, academic achievement and classroom behaviour was available on 645 (74% completion rate). Nearly a third of the cohort was classified as needing special education. Special education placement followed a birthweight gradient, occurring among 29.3% of children with birthweights 1500-2000 g, among 32.5% in children 1000-1500 g and 49.4% in children < 1000 g. Among children in special education, a similar birthweight gradient was found for maths achievement and hyperactivity, but not for reading achievement or IQ scores. Among children not in special education, only maths achievement showed such a decline with birthweight. A substantial proportion of low-birthweight children, including those of moderate low birthweight, receive special education services, although the need is greatest among those with the lowest birthweights. Maths achievement declined with birthweight regardless of educational placement. The medical and social risk factors that accompany low birthweight and may account for these findings, require further study.