Predictors of neurodevelopmental outcome of Malaysian very low birthweight children at 4 years of age

Academic school readiness in children born very preterm and associated risk factors

BACKGROUND AND AIMS

Although the intelligence quotient (IQ) test is useful to assess general cognitive function, it may miss more specific and subtle deficits of learning, working memory, attention and executive function. This study aims to evaluate cognitive performance and academic school readiness (SR) concepts in preterm very low birth weight (PT/VLBW) children, compared to typically developing term controls and to evaluate factors affecting basic (SR) concepts in children with IQ>85.

METHODS

A prospective cohort study of 123 PT/VLBW survivors with birth weights ≤1250 g and 74 term controls born between 2007 and 2009 in Singapore were assessed for school readiness using Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III), Bracken School Readiness Assessment (BSRA-3) and Beery-Buktenica Developmental Test of Visual Motor Integration (VMI) at age 5.5 years. Social risk composite score (SRCS) was calculated based on ethnicity, parental education and family income and marital status. Uni- and multi-variable regressions were conducted to evaluate risk factors associated with poor academic SR in the entire cohort and in those with IQ >85.

RESULTS

Mean gestational age and birth weight of the 123 PT/VLBW children were 27.8 (2.3) weeks and 939 (194) grams while that of the 74 term controls were 38.8 (1.2) weeks and 3165 (402) grams. PT/VLBW survivors had statistically significant lower full composite scores on WPPSI-III (97.0 vs 114), BSRA-3 (98.5 vs 112.3) and VMI (107.2 vs 112.9) compared to controls. The differences remained significant in preterm and children with higher SRCS even after adjustment.

CONCLUSIONS

Prematurity and high social composite risk scores were risk factors affecting academic SR and this difference persisted in PT/VLBW children with normal cognitive scores with IQ >85.

Factors affecting neurodevelopmental outcome at 2 years in very preterm infants below 1250 grams: a prospective study

OBJECTIVE

To evaluate the neurodevelopmental outcomes of preterm very-low birth weight (PT/VLBW) infants at 2 years and identify risk factors associated with significant developmental delay or neurodevelopmental impairment (NDI).

STUDY DESIGN

We evaluated 165 PT/VLBW infants born between January 2010 and December 2011, using the Bayley Scales of Infant and Toddler Development 3rd Edition (Bayley-III). NDI was defined as the presence of neurosensory impairment or significant delay with Bayley-III score < 70 in any domain and risk factors for delay/NDI were assessed using logistic regressions.

RESULTS

Median Bayley-III composite scores in the cognitive, language and motor domains were 95, 89 and 94, respectively. NDI was present in 20% of the children, with 5-18% having significant delay in either cognitive, language or motor domain, seven (4%) children had cerebral palsy, three (2%) were deaf and none were blind. Regression models identified significant positive associations of delayed cognitive skills with male gender (Odds ratio (OR) 22.4, 95% confidence interval (CI) 1.5-341.1; P = 0.025), lack of anntenatal steroids (ANS) (OR 41.5, 95% CI 3.5-485.7; P = 0.003), and hypotension needing inotropes (OR 36.0, 95% CI 2.6-506.0; P = 0.008); delayed language skills with lower maternal education (OR 3.8, 95% CI 1.4-10.3; P = 0.10), lack of ANS (OR 2.8, 95% CI 1.1-7.4; P = 0.04), and 5 minute Apgar Score ≤ 5 (OR 7.4, 95% CI 1.4-38.4; P = 0.017) and delayed motor skills with chronic lung disease at 36 weeks (OR 38.3, 95% CI 2.4-603.4; P = 0.010). NDI was associated with lack of ANS (OR 2.91, 95% CI 1.21-7.00; P = 0.02) and use of postnatal steroids (OR 3.36, 95% CI 1.07-10.54; P = 0.0374).

CONCLUSION

Risk factors for both NDI and individual domain delay were identified and will be helpful in planning of specific and targeted early intervention services.

A gradient relationship between low birth weight and IQ: A meta-analysis

Multiple studies have reported that individuals with low birth weights (LBW, <2500 g) have a lower intelligence quotient (IQ) than those with normal birth weights (NBW, ≥2500 g). Based on 57 eligible individual studies including 12,137 participants, we performed a meta-analysis to estimate the association between low birth weight and individuals' IQ scores (IQs). The pooled weight mean difference (WMD) in IQs between NBW and LBW individuals was 10 (95% CI 9.26-11.68). The WMD was stable regardless of age. No publication bias was detected. The mean IQs of the extremely low birth weight (ELBW, <1000 g), very low birth weight (VLBW, 1000-1499 g), moderately low birth weight (MLBW, 1500-2499 g) and NBW individuals were 91, 94, 99 and 104, respectively. Additionally, the WMD in IQs with NBW were 14, 10 and 7 for ELBW, VLBW, and MLBW individuals, respectively. Two studies permitted estimates of the influence of social determinants of health to the discrepancy in IQs, which was 13%. Since IQ is inherited and influenced by environmental factors, parental IQs and other factors contribute to residual confounding of the results. As the conclusion was based on population studies, it may not be applicable to a single individual.

Long-term neurodevelopmental outcome in high-risk newborns in resource-limited settings: a systematic review of the literature

BACKGROUND

Improving outcomes beyond survival for high-risk newborns in resource-limited settings is an emerging challenge. Global estimates demonstrate the scale of this challenge and significant gaps in morbidity outcome data in high mortality contexts. A systematic review was conducted to document the prevalence of neurodevelopmental impairment in high-risk newborns who were followed up into childhood in low- and middle-income countries.

METHODS

High-risk newborns were defined as low, very or extremely low birthweight, preterm infants or those surviving birth asphyxia or serious infections. Electronic databases were searched and articles screened for eligibility. Included articles were appraised according to STROBE criteria. Narrative review was performed and median prevalence of key neurodevelopmental outcomes was calculated where data quality allowed.

RESULTS

6959 articles were identified with sixty included in final review. At follow-up in early childhood, median estimated prevalence (inter-quartile range) of overall neurodevelopmental impairment, cognitive impairment and cerebral palsy were: for survivors of prematurity/very low birthweight 21.4% (11.6-30.8), 16.3% (6.3-29.6) and 11.2% (5.9-16.1), respectively, and for survivors of birth asphyxia 34.6% (25.4-51.5), 11.3% (7.7-11.8) and 22.8% (15.7-31.4), respectively. Only three studies reporting outcomes following newborn serious bacterial infections were identified. There was limited reporting of important outcomes such as vision and hearing impairment. Major challenges with standardised reporting of key exposure and developmental outcome variables and lack of control data were identified.

CONCLUSION

Understanding the limitations of the available data on neurodevelopmental outcome in newborns in resource-limited settings provides clear direction for research and efforts to improve long-term outcome in high-risk newborns in these settings.

Measures and indicators for assessing impact of interventions integrating nutrition, health, and early childhood development

When implementing interventions integrating nutrition, health, and early childhood development, evaluation studies of effectiveness that assess the intermediate and ultimate impacts on the four domains of food and nutrition, family care, health, and child development are needed. Such studies should demonstrate impact, both benefits and potential harms, and understand mechanisms through which impact has been achieved. This article reviews and suggests measures and indicators suitable for use in evaluation studies of effectiveness of integrated interventions for children under 5 years of age. Within each of the four domains, multiple constructs and subconstructs were considered. For each construct and subconstruct, we identified measures and indicators, using several search processes, and reviewed them in relation to validity, responsiveness to intervention inputs and activities, equivalence in constructs and items across contexts with appropriate adaptation, and feasibility for use in effectiveness studies. Suggested measures and indicators for each domain, construct, and subconstruct are tabulated and described. We discuss the strengths and weaknesses of measures and indicators across domains and constructs, further research establishing validity, and guidance on adaptation of measures to particular contexts.

Rethinking stress in parents of preterm infants: a meta-analysis

BACKGROUND

With improved medical outcome in preterm infants, the psychosocial situation of their families is receiving increasing attention. For parents, the birth of a preterm infant is generally regarded as a stressful experience, and therefore many interventions are based on reducing parental stress. Nevertheless, it remains unclear whether parents of children born preterm experience more stress than parents of term-born children, which would justify these interventions. This meta-analysis provides a comprehensive account of parental stress in parents of preterm infants, from birth of the infant through to their adolescence. Mean levels of stress in specific domains of family functioning were investigated, and stress levels in parents of preterm and term infants, and fathers and mothers of preterm infants, were compared. Furthermore, we investigated moderators of parental stress.

METHODS AND FINDINGS

A random-effects meta-analysis was conducted including 38 studies describing 3025 parents of preterm (<37 wk) and low birth weight (<2500 g) infants. Parental stress was measured with two parent-reported questionnaires, the Parenting Stress Index and the Parental Stressor Scale: Neonatal Intensive Care Unit. The results indicate that parents of preterm-born children experience only slightly more stress than parents of term-born children, with small effect sizes. Furthermore, mothers have slightly more stress than fathers, but these effect sizes are also small. Parents report more stress for infants with lower gestational ages and lower birth weights. There is a strong effect for infant birth year, with decreasing parental stress from the 1980s onward, probably due to increased quality of care for preterm infants.

CONCLUSIONS

Based on our findings we argue that prematurity can best be regarded as one of the possible complications of birth, and not as a source of stress in itself.

High rates of school readiness difficulties at 5 years of age in very preterm infants compared with term controls

OBJECTIVE

School readiness is best understood as a framework for assessing profiles of strengths and vulnerabilities of the preschool-age child. Very preterm (VPT) children are at high risk of difficulties in school, and understanding their school readiness skills has the potential to aid successful transition into school. The aim of this study was to determine the school readiness skills of a cohort of VPT children, compared with term controls.

METHODS

VPT children (gestational age <30 wk or birth weights <1250 g) and term controls were enrolled from a tertiary maternity hospital, Melbourne, Australia into a prospective cohort study. At age 5 years, school readiness skills were evaluated using a combination of parent questionnaires and direct assessments. The 5 domains of school readiness assessed were health and physical development, social-emotional skills, approaches to learning, communication skills, and cognitive skills.

RESULTS

VPT children had standard scores ~½ to 1 SD below those of the term controls in all domains of school readiness, and these differences were not greatly affected by adjustment for social risk differences. Overall, 44% of the VPT group had vulnerabilities in more than 1 domain of school readiness, compared with only 16% of the term controls.

CONCLUSIONS

VPT children are more likely than term controls to have significant vulnerabilities in multiple domains of school readiness, and these differences are mostly independent of social risk.

Parental bilingualism is associated with slower cognitive development in very low birth weight infants

BACKGROUND

Speech development is frequently impaired in very low birth weight (VLBW) infants. Few and controversial data have been published on concepts regarding the influence of bilingual education.

AIMS

The objectives of the current study were to assess the influence of parental bilingualism on speech development and neurodevelopmental outcome in low risk VLBW infants.

STUDY DESIGN

Monocentric prospective controlled cohort study with standardized follow-up.

SUBJECTS

We recruited 50 singleton VLBW infants each from monolingual and bilingual families as well as 90 term control infants. The infants were free of disease and congenital malformation.

OUTCOME MEASURES

Griffiths scales of infant development at the corrected ages of 6 and 12 months, Bayley Scales of Infant Development II (BSID II) with 22 months.

RESULTS

In general, both bilingual and monolingual VLBW infants achieved age-specific milestones at the corrected age of 6, 12 and 22 months. However, bilingual VLBW infants achieved significantly lower scores than their monolingual peers in all cognitive subscales. The influence of maternal education on the neurodevelopmental outcome of the preterm infants was not significant; the subscales' correlation with socioeconomic or biological parameters was poor. However, a clear differentiation between social status and bilingual environment importance for speech development was not possible.

CONCLUSIONS

In the setting of the present investigation, parental bilingualism is associated with slower neurodevelopment in VLBW infants during the first 2 years of life.

Relationship between perinatal and neonatal indices and intelligence quotient in very low birth weight infants at the age of 6 or 8 years

BACKGROUND

The majority of children born with very low birth weight (VLBW; < 1500g) enter mainstream schools. They experience significant neurodevelopmental disabilities during childhood. The specific aims of our study were to evaluate the neonatal outcomes of VLBW infants and whether they would influence intelligence quotient (IQ), cognitive function and learning disabilities at the age of 6 or 8 years.

METHODS

We enrolled VLBW neonates who weighed less than 1500g and who were delivered at Shin-Kong Wu Ho-Su Memorial Hospital in 1996 and 1999. The psychological assessments were applied with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) for age 6 and Wechsler Intelligence Scale for Children-Third Edition (WISC-III) for age 8. We recorded their demographic data, ventilation duration by days, length of stay, use of surfactant, respiratory distress syndrome (RDS), and other complications.

RESULTS

According to whether the full scale intelligence quotient (FSIQ) was above or below the average score (FSIQ = 90), we divided VLBW children into two groups (< 90, n = 17; > or = 90, n = 21). The children with lower gestational age had lower FSIQ (p = 0.013). The higher FSIQ group (> or = 90) showed more prenatal steroid use (5/17, 29.4% vs. 14/21, 66.7%; p = 0.049). There were more boys in the lower FSIQ group (< 90, 13/17, 76.5% vs. > or = 90, 7/21, 33.3%; p = 0.011). The average IQ scores were 78.11 +/- 9.05 and 102.57 +/- 8.89 in the FSIQ < 90 and FSIQ > or = 90 groups, respectively. The groups were similar in ventilation duration by days, use of surfactant, frequency of sepsis, RDS, bronchopulmonary dysplasia, patent ductus arteriosus, intraventricular hemorrhage and retinopathy of prematurity.

CONCLUSION

In our study, the children with lower gestational age had lower FSIQ. There was no significant association between small for gestational age and IQ performance. The neonatal outcomes of VLBW infants did have less impact on IQ performance later in life.

Inter- and intra-modal matching in very low birth weight and small for gestational age adolescents

BACKGROUND

Motor problems in low birth weight children may be related to problems in sensorimotor integration processes. Specific tests of inter- and intra-modal matching have not been used in low birth weight populations.

AIM

Examine whether low birth weight adolescents have poorer performance in inter- and intra-modal matching than normal birth weight adolescents.

STUDY DESIGN

A population based follow up study of very low birth weight and small for gestational age children at 14 years of age.

SUBJECTS

Fifty-three very low birth weight adolescents (VLBW: birth weight < or =1500 g), 59 term small for gestational age (SGA: birth weight <10th centile) and 82 adolescents with birth weight > or =10th centile at term (reference group).

OUTCOME MEASURES

Inter- and intra-modal matching was assessed by a manual matching task and results were presented for the preferred and the non-preferred hand in the visual (inter-modal) and proprioceptive (intra-modal) condition.

RESULTS

VLBW adolescents performed poorer in inter- and intra-modal matching compared with the reference group. However, the results were mainly due to a higher number of adolescents with cerebral palsy (CP) and a low estimated intelligence quotient (IQ(est)) in the VLBW group. SGA adolescents showed poorer performance with their non-preferred hand compared with their preferred hand in both inter- and intra-modal matching, whereas adolescents in the reference group and VLBW adolescents with normal IQ(est) and without CP performed equally well with both hands.

CONCLUSION

VLBW adolescents with normal IQ(est) and without CP do not have major problems in inter- and intra-modal matching. The poorer performance with the non-preferred hand in the SGA group may suggest a specific effect of intrauterine growth retardation.

A randomized, controlled trial of the effectiveness of an early-intervention program in reducing parenting stress after preterm birth

BACKGROUND

Preterm birth has been associated with increased parenting stress in early infancy, and some reports have found this to be a risk factor for later behavioral problems. There are, however, few studies and conflicting results. Information about the fathers is scarce.

OBJECTIVES

Our goal was to study the effects of an early-intervention program on parenting stress after a preterm birth until 1 year corrected age.

METHODS

A randomized, controlled trial was conducted including infants with a birth weight <2000 g treated at the University Hospital of North Norway Trust, which serves the 2 northern-most counties in Norway, to examine the effects of a modified version of the Mother-Infant Transaction Program on parenting stress measured by the Parenting Stress Index. A term control group was also recruited. The Parenting Stress Index was administered to the mothers at 6 and 12 months' corrected age and to the fathers at 12 months' corrected age. The intervention consisted of 8 sessions shortly before discharge and 4 home visits by specially trained nurses focusing on the infant's unique characteristics, temperament, and developmental potential and the interaction between the infant and the parents.

RESULTS

Seventy-one infants were included in the preterm intervention group, and 69 were included in the preterm control group. The preterm groups were well balanced. Seventy-four infants were included in the term control group. Compared with the preterm controls, both the mothers and fathers in the preterm intervention group reported significant lower scores in child domain, parent domain, and total stress on all occasions except the mother-reported child domain at 12 months. These differences were not related to birth weight or gestational age. The level of stress among the preterm intervention group was comparable to their term peers. Both parents in the intervention group reported consistently lower scores within the distractibility/hyperactivity, reinforces parents, competence, and attachment subscales compared with the preterm control group. There were no differences in mean summary stress scores between the mothers and fathers in the 2 preterm groups at 12 months, but the intraclass correlation coefficient was higher in the intervention group.

CONCLUSIONS

This early-intervention program reduces parenting stress among both mothers and fathers of preterm infants to a level comparable to their term peers. We are now studying whether this will result in long-term beneficial effects.

Outcome at 2 years for very low birthweight infants in a geographical population: risk factors, cost, and impact of congenital anomalies

AIM

To determine the type and rate of disability at 2 years of age in infants born in the geographically defined population of East Anglia with a birthweight less than 1500 g and to assess the risk factors for disability.

STUDY DESIGN

A prospective cohort analysis from all eight neonatal units in East Anglia from 1993-1997 using a single database.

METHODS

Local paediatricians assessed children at 2 years using the Health Status Questionnaire and data collection was centrally coordinated.

RESULTS

Outcomes for 947 children, 99% of survivors, were available, 74 (7.8%) had severe disability and this was significantly associated with gestational age (p<0.0005), birthweight (p<0.0005) and sex (p=0.046). Major congenital abnormality contributed 27% of all severe disability. The overall cerebral palsy rate was 6.2%, nine children were blind and five had sensorineural hearing loss requiring aids. These children had a high level of use of community services with 19% of the cohort being referred to one or more community service. ELBW infants or those born <30 weeks gestation were 1.5 times and twice as likely to have moderate or severe disability and 2.3 and 5.4 times as likely to have cerebral palsy as those weighing 1000 to 1500 g or >30 weeks gestation. Boys were at higher risk of adverse outcome.

CONCLUSIONS

The study was able to define the increased risk associated with being born at lower gestational age or lower birthweight and demonstrates successful ascertainment of outcomes for large local populations at a reasonable cost.

Motor skills in adolescents with low birth weight

BACKGROUND

Minor motor problems have been reported in low birthweight children, but few studies have assessed motor skills in adolescents.

OBJECTIVE

To examine the prevalence of motor problems in adolescents with low birth weight.

METHOD

Fifty four very low birthweight (VLBW: birth weight < or = 1500 g), 59 term small for gestational age (SGA: birth weight < 10th centile), and 83 control (birth weight > or = 10th centile at term) children were assessed with the Movement assessment battery for children (Movement ABC) at the age of 14 in a population based study.

RESULTS

One in four VLBW children (odds ratio (OR) 9.3, 95% confidence interval (CI) 2.5 to 34.5) and one in six SGA children (OR 4.7, 95%CI 1.2 to 18.4) had motor problems compared with controls (3.7%). There were no sex differences in motor problems in the VLBW group, and the increased risk was consistent across the continuum of the Movement ABC. For SGA children, the increased risk of motor problems was particularly in manual dexterity in boys.

CONCLUSION

VLBW and SGA adolescents have increased risk of motor problems compared with control children.

Brain volumes in adult survivors of very low birth weight: a sibling-controlled study

OBJECTIVES

To establish whether adults who were born very low birth weight (VLBW) show altered volumes of certain brain structures.

METHODS

Unmatched case-control study was conducted of 33 individuals from a cohort of VLBW (<1500 g) infants who were born between 1966 and 1977 and 18 of their normal birth weight siblings. Whole brain, gray matter, ventricular, corpus callosum, and hippocampal volumes were measured on structural magnetic resonance imaging scans.

RESULTS

VLBW individuals had a 46% increase in total ventricular volume and a 17% reduction in posterior corpus callosum volume. No differences in whole brain, gray matter, or hippocampal volumes were observed.

CONCLUSION

Specific differences exist in the volumes of certain brain structures in adults who were born VLBW compared with their normal birth weight siblings.