Measuring functional outcomes after prematurity: developmental impact of very low birth weight and extremely low birth weight status on childhood disability

Our purpose was to describe functional outcomes in essential activities in preschool, school-age, and adolescent children who were born very (<32 weeks gestation) and extremely (<28 weeks gestation) prematurely. Very low birth weight (VLBW; 1000-1499 g), or extremely low birth weight (ELBW;<1000 g) populations are the focus of our analysis. We describe models of disablement and enablement for specifying the complexity of childhood outcomes using a framework of pathophysiology, impairment, functional limitation and functional strengths, disability in social roles and social participation, societal limitations and environmental facilitators. Representative early childhood, preschool, school-age, and adolescent studies were examined in terms of describing children's functional strengths and challenges after VLBW and ELBW survival. In early childhood, disability was assessed by diagnosing neurosensory impairments and delays on developmental testing. Instruments for measuring functional status in essential activities of self-care, mobility, communication and learning are described. Rates of neurosensory disability in the first three years among recent ELBW survivors ranged from 9-26% for cerebral palsy, 1-15% for blindness, 0-9% for deafness, and 6-42% for evolving cognitive disability (MDI <70). Rates of preschool functional limitation were 5-27% motor, 5-30% self-care, and 5-22% communicative. Rates of school-age functional educational disabilities exceeded 50%. Rates of adolescent activity limitation were 13-32% and vocational limitations were 27-71%. By examining the functional strengths and challenges of children with major neurodevelopmental impairments after very or extremely preterm birth, we can examine causal pathways that lessen the risk of severe functional disability. Among children with mild to moderate disability, we can enhance functional outcomes, optimize community participation, and provide quality family supports. In order to assess the changing outcomes of this vulnerable population of survivors, combinations of clinical and survey based methodologies are required.     

Visual configural processing in adults born at extremely low birth weight

Being born at extremely low birth weight (ELBW; ≤1,000 g) is associated with enduring visual impairments. We tested for long‐term, higher order visual processing problems in the oldest known prospectively followed cohort of ELBW survivors. Configural processing (spacing among features of an object) was examined in 62 adults born at ELBW (M_age = 31.9 years) and 82 adults born at normal birth weight (NBW; ≥2,500 g: M_age = 32.5 years). Pairs of human faces, monkey faces, or houses were presented in a delayed match‐to‐sample task, where non‐matching stimuli differed only in the spacing of their features. Discrimination accuracy for each stimulus type was compared between birth weight groups, adjusting for neurosensory impairment, visual acuity, binocular fusion ability, IQ, and sex. Both groups were better able to discriminate human faces than monkey faces (p < .001). However, the ELBW group discriminated between human faces (p < .001), between monkey faces (p < .001), and to some degree, between houses (p < .06), more poorly than NBW control participants, suggesting a general deficit in perceptual processing. Human face discrimination was related to performance IQ (PIQ) across groups, but especially among ELBW survivors. Coding (a PIQ subtest) also predicted human face discrimination in ELBW survivors, consistent with previously reported links between visuo‐perceptive difficulties and regional slowing of cortical activity in individuals born preterm. Correlations with Coding suggested ELBW survivors may have used a feature‐matching approach to processing human faces. Future studies could examine brain‐based anatomical and functional evidence for altered face processing, as well as the social and memory consequences of face‐processing deficits in ELBW survivors.     

Selective deficit in spatial location memory in extremely low birth weight children at age six: The PETIT Study

Spatial location memory has rarely been assessed in young children due to a scarcity of developmentally appropriate tests. This study sought to compare nonverbal learning and recall in children born extremely low birth weight (ELBW; <1000 g) and less than 33 gestational weeks (GW) with term-born children at early school age using a recently developed and adapted test. We administered a modification of the Hopkins Board to 210 children at age six; 84 born ELBW (35 born < 26 GW; 49 born 26–33 GW) and 126 term-born. Six measures were obtained: naming, trials-to-criterion, errors-to-criterion, delayed item recall, delayed location recall, and percent retention. After age correction, ELBW children had worse general cognition, item naming, delayed item recall, delayed location recall, and percent retention than term-born children. Delayed item recall and percent retention performances of ELBW children remained worse after correction for general cognition. ELBW groups (< 26 GW and 26–33 GW) groups performed worse than term-born children in naming and delayed item recall with chronological age as covariate. Those born before 26 GW, but not 26–33 GW, performed worse than term-born children in delayed location recall and percent retention. Differences remained significant after controlling for gender, maternal education, and delivery type. All three groups' performance declined from final learning trial to delayed location recall, with a decline greater for less than 26 GW than term-born children. Extreme prematurity (< 26 GW) and ELBW are significant risk factors for spatial location memory deficit. The modified Hopkins Board discriminated high-risk preterm and term-born children at early school age and appears to be a useful test to measure this rarely studied cognitive capacity.     

Parenting of low birth weight infants: A review of issues and interventions

Factors that may adversely affect parenting of low birth weight infants, including infant characteristics, parental emotional responses to premature birth, and patterns of parent-infant interaction, are reviewed. In addition, intervention studies designed to improve infant developmental outcomes through influencing parenting behaviors are examined. There was great diversity in theoretical frameworks, in timing of onset and frequency of interventions, and in measurement of outcomes. The interventions that were most effective in influencing behaviors and infant developmental outcomes were those in which there were multiple long-term contacts with parents and/or those that actively involved them in the intervention. The specific theoretical framework upon which the interventions were based appeared to be of less importance in influencing results. In order to increase our knowledge and ability to provide costeffective programs, there is a need to focus attention and data collection efforts on the process and intermediary steps of intervention as well as on outcome measures. There is also a need to improve our ability to recruit and retain those families who are most at risk for parenting and infant developmental problems including those with very low birth weight infants, those whose infants have serious perinatal complications, and those with indications of high social risk such as poverty-level incomes and problems of substance abuse.     

Developmental change in the neuropsychological functioning of very low birth weight infants

Research on very low birth weight (VLBW) infants has not carefully evaluated developmental patterns of neurological and neuropsychological functioning across time. This study reports on a broad range of developmental outcomes for VLBW infants of low (LR, n = 116) and high (HR, n = 84) medical risk compared to full term infants (FT, n = 120) across 6, 12, and 24 months of age. While low risk infants showed initial delays in most areas, faster rates of change in motor and neurological development resulted in catch-up by 2 years of age as compared to the FT infants. The lack of acceleration in development of mental skills demonstrates a persistent lag in this area. In contrast, HR infants showed initial delays in all areas as compared to both LR and FT infants with slower rates of change in mental and expressive language skills. Although faster rates of change were evident for HR infants in motor, neurological, and receptive language skills, scores in these areas remain lower than those for the LR and FT infants. The absence of accelerated rates of development for certain VLBW infants has implications for prognosis and patient access to early intervention services.     

Test of visuospatial construction: Validity evidence in extremely low birth weight and late preterm children at early school age

The Test of Visuospatial Construction (TVSC), a measure of visuoconstruction that does not rely on upper extremity motor response or written production, was administered to extremely low birth weight (ELBW), late preterm (LPT), and term participants at preschool (n = 355) and kindergarten (n = 265) ages. TVSC showed statistically significant weak-to-moderate positive correlations (age 3: r = .118–.303; age 6: r = .138–.348) with Developmental VMI, Differential Ability Scales-II Copying, Matrices, and Pattern Construction subtests, Baron-Hopkins Board Test, and the Purdue Pegboard. One-way ANOVA indicated ELBW performed worse than Term (p = .044) on visuospatial construction at age 3 with a small-to-medium effect size (d = ?0.43). No other statistically significant differences were found at age 3 on the TVSC (ELBW/LPT: p = .608, d = ?0.17; LPT/Term: p = .116, d = ?0.31). At age 6, ELBW participants performed worse than LPT participants (p = .027) and Term participants (p = .012); LPT participants did not differ from Term participants. Small effect sizes at age 3 (ELBW < LPT, d = ?0.17; ELBW < Term, d = ?0.43) were notably larger at age 6 (ELBW < LPT, d = ?0.42; ELBW < Term, d = ?0.53). Important practical differences showing LPT participants performed below Term participants (d = ?0.31) at age 3 were no longer evident at age 6 (d = ?0.097). These findings provide preliminary evidence of TVSC validity supporting its use to detect neuropsychological impairment and to recommend appropriate interventions in young preterm children.     

Still cautious: Personality characteristics of extremely low birth weight adults in their early 30s

Extremely low birth weight survivors (ELBW; <1000 g) display a personality style characterized by cautiousness, shyness, and risk aversion in their 20s. We examined whether non-impaired ELBW survivors were still more cautious than their normal birth weight (NBW) peers at ages 30–35 and assessed the stability of this personality characteristic across approximately a decade in the oldest known cohort of ELBW survivors. Of the 154 participants tested at ages 22–26, 111 (i.e., 72%) of them returned approximately 10 years later [i.e., 69% (49/71) ELBW and 75% (62/83) NBW], and once again they completed the Eysenck Personality Questionnaire-Revised (EPQ-R). We created the same theoretically and empirically derived composite measure of cautiousness at each visit by summing the EPQ-R psychoticism scale (reverse scored) and the EPQ-R lie scale. We found that ELBW adults reported higher cautiousness than their NBW counterparts at ages 30–35. We also found that levels of cautiousness remained stable over approximately 10 years in both groups. Our findings suggest that individuals born at ELBW were more cautious than NBW peers and that this personality characteristic remained stable into their early 30s. The present study appears to be the first empirical demonstration of personality stability among adult ELBW survivors.     

The contribution of visual processing to academic achievement in adolescents born extremely preterm or extremely low birth weight

Children born extremely preterm (EP, <28 weeks) and/or extremely low birth weight (ELBW, <1000 g) have more academic deficiencies than their term-born peers, which may be due to problems with visual processing. The aim of this study is to determine (1) if visual processing is related to poor academic outcomes in EP/ELBW adolescents, and (2) how much of the variance in academic achievement in EP/ELBW adolescents is explained by visual processing ability after controlling for perinatal risk factors and other known contributors to academic performance, particularly attention and working memory. A geographically determined cohort of 228 surviving EP/ELBW adolescents (mean age 17 years) was studied. The relationships between measures of visual processing (visual acuity, binocular stereopsis, eye convergence, and visual perception) and academic achievement were explored within the EP/ELBW group. Analyses were repeated controlling for perinatal and social risk, and measures of attention and working memory. It was found that visual acuity, convergence and visual perception are related to scores for academic achievement on univariable regression analyses. After controlling for potential confounds (perinatal and social risk, working memory and attention), visual acuity, convergence and visual perception remained associated with reading and math computation, but only convergence and visual perception are related to spelling. The additional variance explained by visual processing is up to 6.6% for reading, 2.7% for spelling, and 2.2% for math computation. None of the visual processing variables or visual motor integration are associated with handwriting on multivariable analysis. Working memory is generally a stronger predictor of reading, spelling, and math computation than visual processing. It was concluded that visual processing difficulties are significantly related to academic outcomes in EP/ELBW adolescents; therefore, specific attention should be paid to academic remediation strategies incorporating the management of working memory and visual processing in EP/ELBW children.     

Maternal attachment representations and the development of very low birth weight premature infants at two years of age

There is a consensus that prematurity could increase the risk of attachment impairment. We studied 90 premature children with very low birth weights (<1,500 g) and 96 healthy children born at term with similar age and sociodemographic characteristics. Our objective was to assess maternal stress and attachment representations, and compare development indices on both groups at 2 years of age. Premature infants had a medium‐to‐severe degree of immaturity and biological risk (M gestational age = 29.98 weeks; birth weight = 1,159.76 g), with 57% staying in the ICU ≥1 week. These children born prematurely had lower scores on the development indices within the normal range. Mothers of premature infants (n = 74) reported higher levels of stress during their first year of life (59%) than did controls (41%), but no significant differences were detected in maternal attachment discourse between the two groups. The findings confirm that premature birth has a great influence on maternal emotional responses and the health and development of children in the first years of life, and indicate that stress responses in parents and warning signs for attachment problems should be assessed as early as possible.     

Executive functions in extremely low birth weight and late-preterm preschoolers: Effects on working memory and response inhibition

Executive function (EF) refers to fundamental capacities that underlie more complex cognition and have ecological relevance across the individual's lifespan. However, emerging executive functions have rarely been studied in young preterm children (age 3) whose critical final stages of fetal development are interrupted by their early birth. We administered four novel touch-screen computerized measures of working memory and inhibition to 369 participants born between 2004 and 2006 (52 Extremely Low Birth Weight [ELBW]; 196 late preterm; 121 term-born). ELBW performed worse than term-born on simple and complex working memory and inhibition tasks and had the highest percentage of incomplete performance on a continuous performance test. The latter finding indicates developmental immaturity and the ELBW group's most at-risk preterm status. Additionally, late-preterm participants performed worse compared with term-born on measures of complex working memory but did not differ from those term-born on response inhibition measures. These results are consistent with a recent literature that identifies often subtle but detectable neurocognitive deficits in late-preterm children. Our results support the development and standardization of computerized touch-screen measures to assess EF subcomponent abilities during the formative preschool period. Such measures may be useful to monitor the developmental trajectory of critical executive function abilities in preterm children, and their use is necessary for timely recognition of deficit and application of appropriate interventional strategies.     

Poverty,ethnicity, and risk of obesity among low birth weight infants

The independent and joint effects of family and neighborhood poverty and ethnicity upon weight trajectories from age two to six-and-a-half were examined using data from the Infant Health and Development Program (N = 985), an early intervention program for low birth weight children and families. At age two, family poverty was associated with higher body mass index (BMI), whereas neighborhood poverty and ethnicity were not. Over time, the BMI of toddlers from poor and near poor neighborhoods increased nonlinearly, while those from nonpoor neighborhoods remained stable. BMIs of Hispanic-American toddlers increased steadily over time, unlike African-American and Anglo-American toddlers. Although initially similar, over time African-American toddlers' BMIs increased more rapidly than Anglo-American toddlers. Family and neighborhood poverty and ethnicity were associated with BMI. More work is needed on how poverty and ethnicity contribute to differences in early weight gain in conjunction with sociocultural and environmental factors in the home and community.     

A randomized study of the impact of a sensitizing intervention on the child‐rearing attitudes of parents of low birth weight preterm infants

Nordhov, S. M., Kaaresen, P. I., Rønning, J. A., Ulvund, S. E. & Dahl, L. B. (2010). A randomized study of the impact of a sensitizing intervention on the child‐rearing attitudes of parents of low birth weight preterm infants. Scandinavian Journal of Psychology, 51, 385–391. The background for this study was that nurturant child‐rearing attitudes are associated with positive development in low birth weight (LBW) infants. The objective was to study child‐rearing attitudes and early intervention (EI) in parents of LBW infants from 12–36 months corrected age. LBW infants (BW < 2000 g) were randomized to an intervention (IG) or a control group (CG). The EI consisted of seven in‐hospital sessions prior to discharge, then four home visits. A Child Rearing Practices Report was administered at 12 (mothers only), 24 and 36 months. A total of 146 infants were randomized. The mean BW in IG was 1396 (SD 429) g and 1381 (436) g in CG. The mean GA was 30.2 (3.1) weeks in IG and 29.9 (3.5) weeks in CG. Mothers in IG reported significantly more nurturant child‐rearing attitudes at 12 and 24 months. There was a significant change in restrictive and nurturant attitudes over time. It was concluded that EI may lead to more nurturant child‐rearing attitudes in mothers of preterms.     

Behavioral state organization of very low birth weight infants: Effects of developmental handling during caregiving

Handling infants for nursing care in the neonatal intensive care unit has been associated with physiological and behavioral distress. The purpose of this study was to determine whether an individualized approach to nursing care designed to reduce stressors and support behavioral organization would positively affect behavioral state organization during caregiving. The developmental approach was contrasted with a traditional approach in 38 infants (< 1700 g, 53% female, 85% white) at 28, 30, and 32 weeks postconceptional age. Subjects served as their own controls in a cross-over design, with assessment of four caregiving sessions at each age. Results showed that with developmental caregiving, time spent in sleep and drowsy wakefulness was higher, and time in alert and non-alert wakefulness and fuss/cry was lower than with traditional caregiving. Results demonstrate a positive effect of developmental handling for behavioral state organization. However, the findings for the alert state were unexpected and require further exploration of how alertness may be promoted without the physiological and behavioral costs of disorganized arousal.     

Psychiatric sequelae of low birth weight at 6 years of age

The study examined the association between low birth weight (LBW) (2,500 g) and attention deficit hyperactivity disorder (ADHD) in two socioeconomically disparate populations. LBW and normal birth weight (NBW) children from the 1983 to 1985 newborn lists of an urban and a suburban hospital in Southeast Michigan were randomly selected. A total of 823 children, 473 LBW and 350 NBW, participated. Data were gathered in 1990 to 1992, when the children were 6 to 7 years of age. The National Institute of Mental Health Diagnostic Interview Schedule for children—Parent version (DISC-P) was used to elicit information on DSM-III-R diagnoses of simple phobia, overanxious, separation anxiety, oppositional defiant, and ADHD. Teachers' ratings of behavior problems were obtained. LBW was associated with ADHD but not with childhood anxiety disorders or oppositional defiant disorder. The association was stronger in the urban than in the suburban population. Data from teachers' ratings revealed an association between LBW and attention problems. The prognostic significance of the observed psychopathology at 6 years of age requires follow-up assessment as the children mature.This research was supported by NIMH research grant MH-44586 and NIMH Research Scientist Development Award MH-00380 to Dr. Breslau.     

Mother's attachment representations of their premature infant at 6 and 18 months after birth

The effects of premature birth on attachment have generally been examined from the infant's perspective. There is a lack of data concerning parental attachment representations toward a premature child. Because of the psychological stress engendered in parents confronted with a premature birth, we hypothesized that their attachment representations would be altered during the first months after the hospital discharge. Fifty families with a premature infant (25–33 gestation weeks) and a control group of 30 families with a full‐term infant participated to the study. Perinatal risks were evaluated during hospitalization. To assess mothers' representations of their infant, the Working Model of the Child Interview (WMCI, Zeanah & Benoit, 1995 & Benoit, Zeanah, Parker, Nicholson, & Coolbear, 1997) were administered when their children were 6 and 18 months old. The severity of the perinatal risks was found to have an impact on the mothers' attachment representations. At six months, only 20% of the mothers of a prematurely born infant (30% at 18 months) had secure attachment representations, vs. 53% for the control group (57% at 18 months). Furthermore, mothers of low‐risk premature infants more often had disengaged representations, whereas distorted representations were more frequent in the high‐risk group of premature children. These findings suggest that the parental response to a premature birth is linked to the severity of postnatal risks. The fact that secure attachment representations are affected in mothers of low‐risk infants just as much as they are in mothers of high‐risk infants points to the need to conduct further studies aimed at evaluating whether preventive intervention for both low‐risk and high‐risk premature will be helpful.     

Formula: see text]Executive functions in extremely low birth weight and late-preterm preschoolers: Effects on working memory and response inhibition

Executive function (EF) refers to fundamental capacities that underlie more complex cognition and have ecological relevance across the individual's lifespan. However, emerging executive functions have rarely been studied in young preterm children (age 3) whose critical final stages of fetal development are interrupted by their early birth. We administered four novel touch-screen computerized measures of working memory and inhibition to 369 participants born between 2004 and 2006 (52 Extremely Low Birth Weight [ELBW]; 196 late preterm; 121 term-born). ELBW performed worse than term-born on simple and complex working memory and inhibition tasks and had the highest percentage of incomplete performance on a continuous performance test. The latter finding indicates developmental immaturity and the ELBW group's most at-risk preterm status. Additionally, late-preterm participants performed worse compared with term-born on measures of complex working memory but did not differ from those term-born on response inhibition measures. These results are consistent with a recent literature that identifies often subtle but detectable neurocognitive deficits in late-preterm children. Our results support the development and standardization of computerized touch-screen measures to assess EF subcomponent abilities during the formative preschool period. Such measures may be useful to monitor the developmental trajectory of critical executive function abilities in preterm children, and their use is necessary for timely recognition of deficit and application of appropriate interventional strategies.     

Corrected and uncorrected Bayley scores: Longitudinal developmental patterns in low and high birth weight preterm infants

In this study, we longitudinally investigated developmental changes in very low birth weight (VLBW, less than 1500 gms), in higher birth weight (HBW, 1500–2000 gms) preterm, and in full-term (FT) infants. We also investigated changes in their caretaking home environment. The subjects were 20 VLBW, 39 HBW, and 24 FT infants who participated in an intervention study. Blind independent assessments were performed at 4, 8, 12, and 16 months corrected age using the Bayley mental and motor scales, both corrected for prematurity and uncorrected, the Infant and Toddler temperament questionnaires, and the Caldwell Home Observation for Measurement of the Environment inventory (HOME). The VLBW infants obtained the lowest mental (77) and motor (77) uncorrected scores, which were significantly different from the mental and motor scores of the HBW (94 and 89, respectively) and of the FT (115 and 109, respectively) infants. Mental and motor uncorrected scores were significantly lower at 4 months than at 8, 12, and 16 months. By 12 months, the uncorrected scores of the HBW infants no longer differed from the FT ones, and by 16 months only the difference between the FT and the VLBW was significant. The corrected mental and motor scores yielded no significant group or age differences. Post hoc analysis of an interaction in the motor scores yielded significantly higher scores for the FT than for the VLBW group at the last assessment. Overall, the VLBW infants were more passive and less intense than were either HBW or FT infants. In general, the home environment of the VLBW infants was significantly less stimulating and responsive than was the home environment of the FT and HBW infants. These results are discussed in terms of vulnerability of the VLBW preterm infants to developmental deficits and the difficulties their parents experience in their caretaking role.     

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.     

What infants know about syntax but couldn't have learned: experimental evidence for syntactic structure at 18 months

Generative linguistic theory stands on the hypothesis that grammar cannot be acquired solely on the basis of an analysis of the input, but depends, in addition, on innate structure within the learner to guide the process of acquisition. This hypothesis derives from a logical argument, however, and its consequences have never been examined experimentally with infant learners. Challenges to this hypothesis, claiming that an analysis of the input is indeed sufficient to explain grammatical acquisition, have recently gained attention. We demonstrate with novel experimentation the insufficiency of this countervailing view. Focusing on the syntactic structures required to determine the antecedent for the pronoun one, we demonstrate that the input to children does not contain sufficient information to support unaided learning. Nonetheless, we show that 18-month-old infants do have command of the syntax of one. Because this syntactic knowledge could not have been gleaned exclusively from the input, infants' mastery of this aspect of syntax constitutes evidence for the contribution of innate structure within the learner in acquiring a grammar.