Normal Birth Weight Peers Research Articles

Extremely Low Birth Weight and Accelerated Biological Aging.

Extremely low birth weight (ELBW) (<1000 g) survivors are exposed to elevated levels of physiologic stress during their lives and may be susceptible to accelerated aging. Using the oldest known longitudinally followed cohort of ELBW survivors, we compared biological aging in this group using an epigenetic clock to a sample of matched normal birth weight (NBW) (>2500 g) control participants. Buccal cells were collected from 45 ELBW survivors and 49 NBW control participants at 30 to 35 years of age. Epigenetic age was calculated from the weighted average of DNA methylation at 353 cytosine-phosphate-guanine sequence within DNA sites, by using the Illumina Infinium Human Methylation EPIC 850k BeadChip array. Before and after statistically adjusting for neurosensory impairment and the presence of chronic health conditions, a significant sex by birth weight group interaction was observed in the 353-site epigenetic-clock assay (P = .03), whereby ELBW men had a significantly older epigenetic age than NBW men (4.6 years; P = .01). Women born at ELBW were not found to be epigenetically older than their NBW peers. The results of this study suggest that prenatal exposures may play an important role in aging, and that men born preterm may experience accelerated aging relative to their peers. We further highlight the need to monitor and promote the health of preterm survivors, with a particular focus on healthy aging across the life span.

Psychiatric symptoms and risk factors in adults born preterm with very low birthweight or born small for gestational age at term

BackgroundWe aimed to examine psychiatric symptoms in adults born preterm with very low birthweight or born at term small for gestational age compared with normal birthweight peers, and examine associations with perinatal factors and childhood motor and cognitive function.MethodsIn this longitudinal cohort study, one preterm born group with very low birthweight (VLBW: birthweight ≤1500 g), one term-born Small for Gestational Age (SGA: birthweight <10th percentile) group and one term-born non-SGA control group, were assessed at 26 years of age. Primary outcomes were scores on self-reported questionnaires: Achenbach System of Empirically Based Assessment - Adult Self-Report, The Autism-Spectrum Quotient and Peters et al. Delusions Inventory. Exposure variables were perinatal data, while childhood motor and cognitive function were examined as possible early markers.ResultsBoth the preterm VLBW and the term SGA group reported higher levels of attention, internalizing and externalizing problems compared to the control group. In addition, the VLBW participants reported more critical items and a higher proportion had intermediate level autistic traits, while the SGA participants reported more intrusive behavior. Increasing length of respiratory support and hospital stay in the neonatal period, and motor problems in early adolescence, were associated with adult psychiatric symptoms in the VLBW group.ConclusionsPsychiatric symptoms were frequent in the preterm VLBW group and also in the term-born SGA group. Those who were sickest as babies were most at risk. Motor problems can possibly serve as an early marker of adult psychiatric symptoms in low birthweight individuals.

Special health care needs explains the effect of extremely low birth weight on math but not language achievement

ObjectivesExtremely low birth weight (ELBW; <1kg) adolescents are at risk for special health care needs (SHCN) and poor math achievement compared to normal birth weight (NBW) peers. SHCN are associated with poor academic achievement among NBW children. We hypothesize that SHCN explain the effect of ELBW on math achievement. MethodsWe compared age 14 Woodcock-Johnson Calculation standard scores between 181 ELBW infants and 115 NBW controls. Persistent SHCN included: 1) prescription medication or equipment use, 2) subspecialty or therapeutic service use, or 3) hospitalization. We used nonlinear marginal effects models to decompose the total effect of ELBW on math into the following 4 components: the effect of ELBW controlling for SHCN, the effect of SHCN controlling for ELBW, effect modification by SHCN, and mediated interaction where SHCN is both causal mediator and effect modifier. Models were adjusted for sociodemographic factors. ResultsELBW adolescents had lower mean math scores than NBW peers (81.3 vs. 96.4). SHCN were more common among ELBW adolescents (54.1% vs. 27%). The total effect of ELBW on math scores was −15.7 points (95% CI −21.0, −10.5). The effect of birth weight alone was −7.6 points (95% CI −13.7, −1.4); the effect of SHCN alone was negligible. SHCN interaction and mediated interaction effects each accounted for 25% of the total effect. ConclusionsBirth weight alone explains only half of the effect of ELBW on math achievement. We found evidence of effect modification and mediation by SHCN. Understanding these explanatory pathways may lead to targeted interventions for improved outcomes.

Mental health of extremely low birth weight survivors: A systematic review and meta-analysis.

Although individuals born at extremely low birth weight (ELBW; < 1,000 g) are the most vulnerable of all preterm survivors, their risk for mental health problems across the life span has not been systematically reviewed. The primary objective of this systematic review and meta-analysis was to ascertain whether the risk for mental health problems is greater for ELBW survivors than their normal birth weight (NBW) peers in childhood, adolescence, and adulthood. Forty-one studies assessing 2,712 ELBW children, adolescents, and adults and 11,127 NBW controls were reviewed. Group differences in mental health outcomes were assessed using random effects meta-analyses. The impacts of birthplace, birth era, and neurosensory impairment on mental health outcomes were assessed in subgroup analyses. Children born at ELBW were reported by parents and teachers to be at significantly greater risk than NBW controls for inattention and hyperactivity, internalizing, and externalizing symptoms. ELBW children were also at greater risk for conduct and oppositional disorders, autistic symptoms, and social difficulties. Risks for parent-reported inattention and hyperactivity, internalizing, and social problems were greater in adolescents born at ELBW. In contrast, ELBW teens self-reported lower inattention, hyperactivity, and oppositional behavior levels than their NBW peers. Depression, anxiety, and social difficulties were elevated in ELBW survivors in adulthood. Group differences were robust to region of birth, era of birth, and the presence of neurosensory impairments. The complex needs faced by children born at ELBW continue throughout development, with long-term consequences for psychological and social well-being. (PsycINFO Database Record

Health-Related Quality of Life Trajectories of Extremely Low Birth Weight Survivors into Adulthood

To compare the health-related quality of life (HRQL) trajectories of a regional cohort of extremely low birth weight (ELBW, <1000 g) survivors (births from 1977 to 1982) and a group of normal birth weight (NBW) controls, at 3 ages: 12-16 years, 22-26 years, and 29-36 years, spanning over 20 years. We hypothesized that the HRQL of the ELBW cohort would be significantly compromised compared with their NBW peers, and that neurosensory impairments (NSI) would have an additional negative effect. We used the Health Utilities Index Mark 3, in which health status was self-assessed and utility scores were derived from community preferences; multilevel modeling was used to delineate trajectories of HRQL among ELBW survivors with (n = 37) and without NSI (n = 116), and NBW controls (n = 137). Adjusting for participant sex and socioeconomic status at age 8 years, ELBW survivors with NSI had consistently lower HRQL compared with both ELBW survivors without NSI and NBW controls, from adolescence through to adulthood (β = -0.264; P < .001). ELBW survivors without NSI also had significantly lower HRQL compared with NBW controls (β = -0.092; P < .01). At all ages, differences seen in the Health Utilities Index Mark 3 scores between ELBW participants and NBW controls were clinically important, though there was no differential rate of decline between the 2 groups. ELBW survivors manifest meaningfully poorer HRQL from their early teens through their mid-30s. Individuals with NSI appear to represent a distinct group of ELBW survivors with substantially lower HRQL at all ages. Information on HRQL can be helpful in prioritizing research and intervention strategies.

The Effects of Low Birth Weight on School Performance and Behavioral Outcomes of Elementary School Children in Oman

Our study aimed to examine the effects of low birth weight (LBW) on the school performance and behavior of elementary school children in Oman. . Data were gathered through a cross-sectional survey of nine elementary schools from the Muscat and A'Dhahirah regions. The study utilized a unique database created by linking information from the children's health cards and current academic and behavioral performance records. Information on children's performance in various areas such as language, mathematics, science, information technology, sports, and behavior were obtained from the school registers. Birth weight (BW) and selected sociodemographic data were obtained from the copy of their health cards kept by each school. A total of 542 elementary school children aged 7-11 years, who had completed grades 2-4, were surveyed. . Data from the school register revealed a very high rate (17.7%) of LBW and, overall, 12% of the children exhibited below average performance on selected outcome measures. The below average school performance varied from 5-17% across the six selected areas of school performance. The highest rate of below average performance was observed in science (17%), followed by arithmetic and language (16% each). BW showed significant differential effects on school performance and behavioral outcomes, which remained significant after controlling for the effect of potential confounders. It was found that LBW children were 2-6 times more likely to have poorer school performance in all areas than their normal BW peers. . Early intervention programs or special care for LBW children in school could be an effective means of improving educational outcomes and the behavior of these children. Attempts should be made to reduce or prevent poor pregnancy outcomes, which, in turn, would reduce the cost of the health, education, and social services systems.

Executive Function in Low Birth Weight Preschoolers: The Moderating Effect of Parenting.

Previous meta-analyses have identified moderate deficits in executive function (EF) in children born low birth weight (birth weight < 2500 g; LBW). The current study tests the joint contribution of LBW and parenting quality on trajectories of executive function in 1121 preschoolers (50 % boys). We estimated latent growth curve models to represent linear change in EF from 3 to 5 years of age, and tested the impact of LBW, parenting, and their interaction, on the estimated trajectory parameters. Although LBW was related to lower EF ability at all three time points (Cohen's d = 0.43-0.55), LBW children who experienced high levels of sensitive parenting in toddlerhood exhibited faster rates of improvement in EF, and were virtually indistinguishable from their normal birth weight peers by age 5. On the other hand, LBW children who experienced below average levels of sensitive parenting showed lasting deficits in EF ability. These findings suggest that sensitive parenting may buffer LBW children from lasting deficits in EF. Implications of these findings for future interventions are discussed.

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

Extremely low birth weight survivors (ELBW; <1000g) 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 10years 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 10years 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.

Academic achievement of adolescents born with extremely low birth weight

To assess academic achievement, rates of learning disabilities (LD) and special education in extremely low birth weight (ELBW <1 kg) adolescents relative to normal birth weight (NBW) controls and to identify cognitive weaknesses. Compared 181 ELBW adolescents born from 1992 to 1995 (mean age 14.8 years, mean BW 809 g, mean GA 26.4 weeks) and 115 NBW term controls. Measures included tests of IQ, reading and math achievement and executive function. Analyses included ANCOVA and logistic and linear regression. Covariates were sex, race and socioeconomic status. Extremely low birth weight adolescents had significantly lower scores on tests of IQ (87.1 vs. 96.4), achievement (88.6 vs. 95.5 reading; 81.3 vs. 93.2 math) and executive function than the NBW group (all p-values <0.001). ELBW also had higher rates of math LD, 51(50%) vs. 26 (28%), OR (95% CI) = 3.10 (1.65, 5.84), p < 0.001, and need for special education, 88 (49%) vs. 11(10%), OR (95% CI) = 11.78 (5.67, 24.47), p < 0.001. Measures of executive function were related to math independent of IQ. Extremely low birth weight adolescents born in the 1990s have poorer achievement and higher rates of math LD than NBW peers. The findings suggest a need for more intensive interventions addressing the specific cognitive vulnerabilities in this population.

Quality of Life of Formerly Preterm and Very Low Birth Weight Infants From Preschool Age to Adulthood: A Systematic Review

The goal of this systematic review was to synthesize studies that examined the health-related quality of life of preschool- and school-aged children, adolescents, and young adults who were born preterm and/or at very low birth weight. We searched 7 databases up to September 2006 (Medline, PubMed, Embase, EBM Reviews, Cumulative Index of Nursing and Allied Health Literature, PsycINFO, and the Educational Resource Information Center) as well as gray literature sources. We independently screened studies and included them only if a quality-of-life outcome measure was used and findings compared preterm, very low birth weight, or extremely low birth weight infants with term or normal birth weight peers. We independently assessed the methodologic quality of each study by using criteria adapted from the Centre for Reviews and Dissemination. Fifteen cohort or cross-sectional studies met the review criteria. In 6 studies of preschool-aged children, differences were found between study and control groups, suggesting that many preschool children born preterm or at very low birth weight perform more poorly than their peers in physical, emotional, and/or social functioning. Extremely low birth weight school-aged children had lower health utility scores compared with their peers, and similar results were found for adolescents. Parents of preterm and very low birth weight teens noted significantly poorer performance in their child's global health, behavior, and physical functioning, whereas the teenagers themselves did not. In young adulthood, differences in physical functioning remained, but subjective quality of life was similar to normal birth weight peers. The effects of preterm birth/very low birth weight on health-related quality of life seem to diminish over time, which possibly reflects issues related to a child's report versus a parent-proxy report, differing definitions of health-related quality of life, and adaptation of individuals over time, versus true change in health-related quality of life.

Comparison of Current Health, Functional Limitations, and Health Care Use of Young Adults Who Were Born With Extremely Low Birth Weight and Normal Birth Weight

The objective of this study was to compare the current health status, physical ability, functional limitations, and health care use of extremely low birth weight and normal birth weight young adults. A longitudinal study was conducted of a population-based cohort of 166 extremely low birth weight survivors (501-1000 g birth weight; 1977-1982 births) and a group of 145 sociodemographically comparable normal birth weight individuals. Current health status, history of illnesses, hospitalizations, use of health resources, and physical self-efficacy were assessed through questionnaires that were administered to the young adults by masked interviewers. Individuals completed the assessments at a mean age of 23 years. Neurosensory impairments were identified in 27% of extremely low birth weight and 2% of normal birth weight individuals. No differences were reported in the current health status for physical or mental summary scores. Extremely low birth weight young adults reported a higher prevalence of chronic health conditions in the past 6 months. A significantly higher proportion of extremely low birth weight individuals had functional limitations in seeing, hearing, and dexterity and experienced clumsiness and learning difficulties. Except for prescription glasses, medications for depression, and home-care services for extremely low birth weight individuals, there were no significant differences between groups in use of health care resources. Extremely low birth weight individuals had significantly weaker hand grip strength and lower scores for physical self-efficacy, perceived physical ability, and physical self-confidence. Extremely low birth weight young adults seem to enjoy similar current health status to their normal birth weight peers. However, they continue to have significantly poorer physical abilities and a higher prevalence of chronic health conditions and functional limitations. Contrary to expectations, they do not pose a significant burden to the health care system at young adulthood.

School Achievement in a Regional Cohort of Children Born Very Low Birthweight

Children born very low birthweight (VLBW, <=1500 g) have historically had lower average school achievement than their normal birthweight peers. However, perinatal care and survival have changed dramatically since prior cohorts accrued, prompting reassessment. Surfactant therapy became generally available 8/1/1990, and the use of ante- and postnatal steroids increased substantially around this time. Standardized test scores and teacher ratings in math, reading, science, and social studies were obtained at age 10 for a cohort of children admitted to six regional NICUs in Wisconsin and Iowa, 8/1/1988 - 6/30/1991. We compared achievement between the VLBW cohort and controls from the same school districts. Among VLBW children, we determined neonatal and early childhood factors associated with achievement on standardized tests (ordinal logistic regression) and teacher ratings (linear regression) and evaluated whether achievement differed by birth year. Compared to population controls, VLBW children's greatest deficits occurred in mathematics. Scores on the standardized math exam and teacher ratings of overall achievement were positively associated with birthweight, social function measured at age five, and socioeconomic status. VLBW children born in the post-surfactant era (after 8/1/1990) had lower achievement on the standardized math exam than children born during the pre-surfactant era of the prior two years. Lower achievement in the post-surfactant era may be due to greater survival among less healthy neonates or increased exposure to postnatal steroids. VLBW children more likely to struggle academically could be identified by early childhood measures, allowing for targeted interventions to mitigate their difficulties.

Executive functioning in school-aged children who were born very preterm or with extremely low birth weight in the 1990s.

To determine the frequency, nature, and severity of executive dysfunction (EDF) at 8 years of age in extremely low birth weight (ELBW)/very preterm infants who were born in the 1990s, compared with normal birth weight (NBW) control subjects. A geographically determined cohort study was conducted in Victoria, Australia. The ELBW/very preterm cohort comprised 298 consecutive survivors at 2 years of age who had gestational ages <28 completed weeks or birth weights <1000 g and were born during 1991-1992. The NBW cohort comprised 262 randomly selected children of birth weight >2499 g matched on date of birth, gender, ethnicity, and health insurance status. The participation rate was 92% (275 of 298) for the ELBW/very preterm cohort and 85% (223 of 262) for the NBW cohort. Cognitive and behavioral measures of executive functioning were administered. The ELBW/very preterm cohort exhibited significant EDF compared with their NBW peers in all areas assessed. The cognitive assessment revealed global impairment rather than deficits in specific executive domains. The ELBW/very preterm children also displayed more behavioral problems indicative of EDF than the NBW children. Severe impairments were exhibited in only a small minority of ELBW/very preterm children. No statistical conclusions were altered after adjustment for sociodemographic variables or when children with substantial neurosensory impairment were excluded. School-aged children who were born in the 1990s and were very preterm or had ELBW are at greater risk for developing EDF and require ongoing neuropsychological review throughout middle childhood.

A 16-year study of low birth weight infants in China

Conclusions: Adolescents in China who were low birth weight (LBW) lag behind normal birth weight peers in height cognitive ability and school achievement. As the first study in China of long-term outcome our findings suggest that LBW adolescents represent a population in need of support. The isolation of China during the research period and the homogeneity of its social and family structures provide a unique setting for the study of LBW outcome but also highlight the importance of additional studies with larger cohorts from other regions of the country. (excerpt)

Cognitive and neuropsychological outcomes: more than IQ scores.

Improved survival in preterm infants has broadened interest in cognitive and neuropsychological outcomes. The incidence of major disabilities (moderate/severe mental retardation, neurosensory disorders, epilepsy, cerebral palsy) has remained consistent, but high prevalence/low severity dysfunctions (learning disabilities, ADHD, borderline mental retardation, specific neuropsychological deficits, behavioral disorders) have increased. The follow-up literature contains methodologic problems that make generalizations regarding outcome difficult, and these are discussed. Although mean IQs of former VLBW infants generally are in the low average range and are 3-9 points below normal birth weight peers, these scores mask subtle deficits in: visual-motor and visual-perceptual abilities, complex language functions, academics (reading, mathematics, spelling and writing), and attentional skills. There is an increased incidence of non-verbal learning disabilities, need for special educational assistance, and behavioral disorders in children born prematurely. Males have more problems, and there is a trend for worsening outcome over time, due to emergence of more subtle deficits in response to increased performance demands. In addition to IQ and achievement testing in follow-up, there should be evaluation of executive functions and attention, language, sensorimotor functions, visuospatial processes, memory and learning, and behavioral adjustment.

Health-related quality of life of preterm children and their caregivers.

As advances in medical science have extended the limit of viability downward to 23 or 24 weeks gestation, interest has turned from long-term health outcomes to quality of life for survivors. During the last decade, the first studies of the health-related quality of life (HRQOL) of children and young adults who were born extremely preterm were published. Taken from the fields of anthropology, economics, sociology, and psychology, the foundation of HRQOL is formed by theories of functionalism, positive well-being, and utility. HRQOL can be defined as the physical, psychological, and social domains of health, which can be influenced by an individual's experiences and perception. HRQOL instruments are generally composed of multiple domains and measure physical functioning, mental health, and social role functioning in some form. Utilities, or preferences for health outcomes under conditions of uncertainty, are also used. Studies of HRQOL to-date indicate that preterm children have, on average, poorer health than their normal birthweight peers, but the majority do not perceive their quality of life as significantly different than others of their own age. Measures of HRQOL should not replace the traditional measures of morbidity, but should become part of the standard battery of tools used to assess a preterm child's health and well-being. Ultimately, studies of the HRQOL of preterm children should identify aspects of life, physical, psychological, or social, that could be improved with intervention.

Very low birth weight and growth into adolescence.

To compare the growth and pubertal development of very low-birth-weight (VLBW) children (birth weight <1500 g) and normal-birth-weight (NBW) children (birth weight >2499 g) to adolescence to determine if, and at what age, VLBW children "catch up." Inception cohort study to age 14 years. Royal Women's Hospital, Melbourne, Australia. Eighty-six consecutive survivors with a birth weight less than 1000 g, 120 consecutive survivors with a birth weight of 1000 to 1499 g, and 60 randomly selected NBW controls. Children with cerebral palsy at age 14 years were excluded. Weight, height, and head circumference measurements at birth and ages 2, 5, 8, and 14 years converted to z (SD) scores. At age 14 years, pubertal development was similar in NBW and VLBW children. At ages 2, 5, 8, and 14 years, VLBW children were significantly shorter and lighter and had smaller head circumferences than NBW children. The differences in height and weight between VLBW and NBW children were less apparent as SD scores improved in VLBW children over time. Within the VLBW group, compared with children with a birth weight of 1000 to 1499 g, those with a birth weight less than 1000 g had significantly lower weight z scores earlier in childhood but not at age 14 years, significantly lower height z scores only at age 2 years, and significantly lower head circumference z scores throughout childhood. This group of VLBW children experienced late catch-up growth to age 14 years but remain smaller than their NBW peers. Arch Pediatr Adolesc Med. 2000;154:778-784

Long-term outcome for non-handicapped low birth weight infants--is the fog clearing?

The frequency of cerebral palsy increases with decreasing gestational age affecting approximately 7% of survivors with birth weights less than 1500 g (very low birth weight, VLBW) [7]. In addition, low birth weight (birth weight less than 2500 g, LBW) and VLBW children without cerebral palsy or other major neurohandicaps have an increased frequency of "new morbidities" including learning disabilities, behavioural problems, lower mean IQ, and motor clumsiness compared to normal birth weight peers [15, 16, 20]. However, understanding is still lacking regarding the nature and frequency of such problems, predisposing risk factors, and the relationship of such problems with parental factors, including socio-economic status. A fundamental concept for understanding the large and often confusing literature on LBW and later neurobehavioral development is that LBW may have many different aetiologies, with varying relative frequency in different populations, which probably have different degrees of associated risk for impairment of later development.

The effect of low birthweight on the school performance and behavior of school-aged children

This study examines the school performance and behavior of children aged six to fifteen years who were born weighing less than 2500 g, compared with a group of normal birthweight children, holding constant socio-economic characteristics of the child and family. Data on 7733 children from families responding to the nationally representative 1988 National Health Interview Survey are analyzed. Overall, we find that low birthweight children are more likely to repeat a grade in school and are more likely to attend special education classes, even when holding constant the current health status of the child. We find little evidence, however, that low birthweight children have more behavioral problems than their normal birthweight peers.

Visual impairment in very low birthweight children

AIMSTo compare the visual function of a cohort of very low birthweight (VLBW) children in early adolescence with that of their normal birthweight peers; to correlate visual impairment in this...