Update on neurodevelopmental outcomes of infants born prematurely

The Synergistic Effects of Preterm Birth and Parent Gender on the Linguistic and Interactive Features of Parent-Infant Conversations

PURPOSE

To investigate the language environments experienced by preterm-born infants, this study compared the linguistic and interactive features of parent-infant conversations involving 2-year-old preterm- and term-born infants. The study also explored how mother-infant and father-infant conversations may be differentially affected by preterm/term birth status.

METHOD

Twenty-two preterm-born (< 37 weeks' gestation) and 25 term-born (≥ 37 weeks' gestation) 2-year-old infants engaged in dyadic mother/father-infant free-play interactions that were transcribed to quantify the linguistic (parental volubility, speech rate, lexical diversity, and morphosyntactic complexity) and interactive (infant/parent responsiveness, turn-taking, and conversational balance) features of parent-infant conversations. Language, cognitive, socioemotional, and executive function skills were assessed via standardized tools.

RESULTS

Compared to the term group, the preterm group was characterized by lower maternal speech rate, parental lexical diversity, and parent-infant turn-taking, as well as greater mother-infant conversational balance. The preterm group presented poorer language and executive function skills when compared to the term group.

CONCLUSIONS

Both similarities and differences exist between the language environments of preterm and term groups. Similarities may be due to the partial developmental catch-up of preterm-born infants (cognitive and socioemotional skills) and parental scaffolding. Differences may partly reflect a parental adaptation to the language and executive function difficulties of preterm-born infants. These findings suggest that researchers/clinicians should appraise the language environment with respect to the unique developmental needs of preterm/term-born infants. Future research directions are provided to advance a more holistic characterization of the language environment and a deeper understanding of the developmental significance of preterm-term differences in such environments.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25021931.

Parent-infant conversations are differentially associated with the development of preterm- and term-born infants

Preterm birth is a risk factor for language difficulties. To better understand the language development of preterm-born infants, the current study investigated the concurrent associations between parent-infant conversations and the development of 22 preterm-born and 25 term-born infants at 2 years of age. Conversations occurring during mother/father-infant free-play interactions were analyzed to characterize features of parental speech (volubility, speech rate, lexical diversity, and morphosyntactic complexity) and parent-infant exchanges (parent responsiveness, turn-taking, and conversational balance). The infants' language development (receptive communication and expressive communication) and non-language development (cognitive, social-emotional, and executive function) was assessed using standardized measures. Parent-infant conversations were associated with both language and non-language development. This suggests that parent-infant conversations may support language development directly and/or through advancing non-language skills that could promote language learning. The associations between parent-infant conversations and development varied as a function of birth status (preterm or term). This finding may signal the operation of different developmental processes within preterm- and term-born groups. Finally, infant development was differentially associated with mother-infant and father-infant conversations. This may point to the distinct contributions made by mothers and fathers to the development of both preterm- and term-born infants. To optimize language outcomes, these findings indicate that families should be guided to tailor parent-infant conversations to the unique developmental needs and processes of preterm-born infants. Families should also be supported to leverage the distinct developmental contributions of mothers and fathers. Future recommendations are made regarding how to investigate the proposed preterm-term differences in language development processes and the differential developmental contribution of mothers and fathers.

Sleep state organisation of moderate to late preterm infants in the neonatal unit

BACKGROUND

Sleep supports neurodevelopment and sleep architecture reflects brain maturation. This prospective observational study describes the nocturnal sleep architecture of healthy moderate to late preterm (MLP) infants in the neonatal unit at 36 weeks post menstrual age (PMA).

METHODS

MLP infants, in the neonatal unit of a tertiary hospital in Ireland from 2017 to 2018, had overnight continuous electroencephalography (cEEG) with video for a minimum 12 h at 36 weeks PMA. The total sleep time (TST) including periods of active sleep (AS), quiet sleep (QS), indeterminate sleep (IS), wakefulness and feeding were identified, annotated and quantified.

RESULTS

A total of 98 infants had cEEG with video monitoring suitable for analysis. The median (IQR) of TST in the 12 h period was 7.09 h (IQR 6.61-7.76 h), 4.58 h (3.69-5.09 h) in AS, 2.02 h (1.76-2.36 h) in QS and 0.65 h (0.48-0.89 h) in IS. The total duration of AS was significantly lower in infants born at lower GA (p = 0.007) whilst the duration of individual QS periods was significantly higher (p = 0.001).

CONCLUSION

Overnight cEEG with video at 36 weeks PMA showed that sleep state architecture is dependent on birth GA. Infants with a lower birth GA have less AS and more QS that may have implications for later neurodevelopment.

IMPACT

EEG provides objective information about the sleep organisation of the moderate to late preterm (MLP) infant. Quantitative changes in sleep states occur with each week of advancing gestational age (GA). Active sleep (AS) is the dominant sleep state that was significantly lower in infants born at lower GA. MLP infants who were exclusively fed orally had a shorter total sleep time and less AS compared to infants who were fed via nasogastric tube.

Sex Differences in the Association of Pretransfusion Hemoglobin Levels with Brain Structure and Function in the Preterm Infant

OBJECTIVE

To assess sex-specific differences in early brain structure and function of preterm infants after red blood cell (RBC) transfusions.

STUDY DESIGN

A single-center subset of infants with a birth weight <1000 g and gestational age 22-29 weeks were enrolled from the National Institute of Child Health and Human Development's Neonatal Research Network Transfusion of Prematures Trial. Hemoglobin (Hb) concentration obtained directly before each transfusion (pretransfusion Hb [ptHb]) was obtained longitudinally throughout each infant's neonatal intensive care unit stay and used as a marker of degree of anemia (n = 97). Measures of regional brain volumes using magnetic resonance imaging were obtained at ∼40 weeks postmenstrual age or at hospital discharge, if earlier (n = 29). Measures of brain function were obtained at 12 months corrected age using the Bayley Scales of Infant & Toddler Development, 3rd Edition (n = 34).

RESULTS

PtHb was positively correlated with neonatal cerebral white matter volume in males (B = +0.283; P = .006), but not females (B = -0.099; P = .713), resulting in a significant sex interaction (P = .010). Bayley-III gross motor scores and a pooled mean score were significantly lower in association with higher ptHb in females (gross motor score: B = -3.758; P = .013; pooled mean score: B = -1.225; P = .030), but not males (gross motor score: B = +1.758; P = .167; pooled mean score: B = +0.621; P = .359). Higher ptHb was associated with descriptively lower performance on multiple Bayley-III subscales in females, but not in males.

CONCLUSIONS

This study demonstrates sex-specific associations between an early marker of anemia and RBC transfusion status (ie, ptHb) with both neonatal white matter volume and early cognitive function at age 12 months in preterm infants.

Sex-specific cytokine responses and neurocognitive outcome after blood transfusions in preterm infants

BACKGROUND

The objective of this study was to determine sex-specific differences in inflammatory cytokine responses to red blood cell (RBC) transfusion in preterm infants in the neonatal period and their relationship to later neurocognitive status.

METHODS

Infants with a birth weight <1000 g and gestational age 22-29 weeks were enrolled in the Transfusion of Prematures (TOP) trial. The total number of transfusions was used as a marker of transfusion status. Nineteen cytokines and biomarkers were analyzed from 71 infants longitudinally during the neonatal period. Twenty-six infants completed the Bayley Scales of Infant & Toddler Development, 3rd Edition (Bayley-III) at 12 months' corrected age.

RESULTS

Nine cytokine levels were significantly elevated in proportion to the number of transfusions received. Of those, one cytokine showed a sex-specific finding (p = 0.004): monocyte chemoattractant protein-1, MCP-1, rose substantially in females (8.9% change per additional transfusion), but not in males (-0.8% change). Higher concentrations of MCP-1 exclusively were associated with worse Bayley-III scores: decreased cognitive raw scores (p = 0.0005) and motor scaled scores (p < 0.0001).

CONCLUSIONS

This study provides evidence of a sex-specific difference in the inflammatory response to RBC transfusions during neonatal life, with MCP-1 levels rising only in females and inversely correlating with neurocognitive status at 12 months old.

IMPACT

It is important to understand the risk factors for abnormal neurodevelopment in preterm infants, including anemia and RBC transfusion, in order to improve outcomes and provide potential targets for therapy. Our study investigates and provides the first evidence of sex-specific differences in inflammatory cytokine responses to RBC transfusions in preterm infants in the neonatal period, and their relationship to later cognitive outcomes. This study critically suggests that different transfusion thresholds may have a sex-specific effect on neurodevelopment: females have worse cognitive outcomes with increased number of transfusions, while males have worse outcomes with lower number of transfusions.

Toddler motor performance and intelligence at school age in preterm born children: A longitudinal cohort study

BACKGROUND

Current knowledge regarding differences in verbal intelligence scores (VIQ) and performance intelligence scores (PIQ) in preterm born children is limited. As early motor performance may be essential for developing later visual-perceptual and visual-motor skills, early motor performance may be associated with PIQ.

AIMS

To evaluate whether in preterm born children motor performance at two years was associated with PIQ at eight years.

METHODS

Single-centre cohort study including 88 children born <30 weeks' gestation between 2007 and 2011, who completed the Bayley Scales of Infant and Toddler Development-III (BSID-III) at two years and the Wechsler Intelligence Scale for Children-III-NL (WISC-III-NL) at eight years. Outcome measurements (mean (SD)) were gross and fine motor performance based on the BSID-III, and PIQ and VIQ based on the WISC-III-NL. Linear regression analysis was performed to evaluate the association between motor performance at two years and PIQ at eight years.

RESULTS

At two years, mean BSID-III gross motor scaled score was 9.0 (SD 3.0) and fine motor score was 11.5 (SD 2.3). At eight years, mean PIQ was 94.9 (SD 13.5) and mean VIQ 101.8 (SD 13.7). A one-point increase in fine motor scaled score was associated with 1.7 points (95% CI 0.5-2.8) increase in PIQ. Gross motor scaled score was not associated with PIQ.

CONCLUSIONS

Fine motor performance in toddlerhood was related to PIQ at school age, with lower scores indicating a lower PIQ. Early assessment of fine motor performance may be beneficial in identifying children at risk for lower performance intelligence.

The Test of Infant Motor Performance (TIMP) in very low birth weight infants and outcome at two years of age

OBJECTIVE

To evaluate TIMP in preterm very low birth weight (VLBW) infants, analyze risk factors, for atypical TIMP (aTIMP) scores, and explore TIMP's predictive relationship with Bayley-III at 2 years.

METHOD

A prospective study of 288 VLBW infants, with TIMP assessment between 34 weeks postmenstrual age and 16 weeks age, corrected for prematurity.

RESULT

aTIMP scores were observed in 58/288(20%) infants, whose mean birth weight (BW) and gestational age were 1122 ± 257 g and 29.2 ± 2.12 weeks respectively. Risk factors included BW < 750 g (OR 4.8, 95% CI 1.3-17.7) and 750-1000 g (OR 2.9, 95% CI 1.2-6.9), presence of necrotizing enterocolitis ≥ stage 2; or focal intestinal perforation (OR 4.6, 95% CI 1.4-14.4), periventricular leukomalacia (OR 22.4,95% CI 2.0-246.2), and need for intensive resuscitation at birth (OR 2.7, 95% CI 1.3-5.5). aTIMP scores correlated with Bayley-III Score <85 in motor and cognitive domains with high specificity (80-82%) and negative predictive value (85-94%).

CONCLUSION

Identification of the risk factors for aTIMP scores will enable targeted intervention to optimize resources and outcomes in VLBW infants.

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.

Family Integrated Care (FICare): Positive impact on behavioural outcomes at 18 months

BACKGROUND

Children born very preterm demonstrate behavioural challenges due to clinical factors, exposure to the high stress environment of intensive care, and separation from parents during neonatal hospitalization at a critical stage in development. Family Integrated Care (FICare) significantly reduced parent stress and anxiety, and improved neonatal outcomes.

AIMS

To examine the impact of FICare on behavioural outcomes at 18-21 months corrected age (CA), and assess possible mediation through parenting or infant growth.

STUDY DESIGN AND METHODS

A prospective cohort study enrolling infants under 33 weeks gestation and parents from the FICare cluster randomized controlled trial. Primary outcome was behaviour assessed by the Infant Toddler Social Emotional Assessment (ITSEA). Parent child variables were measured with the Nursing Child Assessment Satellite Training (NCAST), Parenting Stress Index (PSI) and infant growth.

RESULTS

Subjects included 123 FICare infants and 62 standard care controls evaluated at 18-21 months CA. FICare infants demonstrated lower ITSEA Dysregulation, indicating better self-regulation skills, compared with the control group (T-score 41.7 vs 46.6, p < 0.01). At 12 months CA, the NCAST Child subtotal score was higher and the PSI-Child Domain score was lower in FICare infants than non-FICare infants. The PSI-Child domain was identified as a possible mediator of FICare on child behaviour (mediation effect 1.28, -2.96-0.02, p = 0.044).

CONCLUSION

FICare in the NICU has a sustained effect on child behaviour, improving self-regulation at 18-21 months CA.

Low Birth Weight and Psychoeducational Outcomes: Investigation of an African American Birth Cohort

African Americans experience more than double the prevalence of low birth weight (LBW)/premature birth compared to their Caucasian counterparts, reflecting a public health crisis and a significant social justice concern. However, there is a paucity of LBW outcome studies in African American samples. There are even fewer that investigate developmental outcomes within the moderately LBW range (i.e., 1500–2500 g), the most prevalent category of LBW births. This study investigates the relationship between LBW and various psychoeducational outcomes in a prospectively designed African American birth cohort. Multivariate logit analyses of the Johns Hopkins University Pathways to Adulthood study compared LBW children with normal birth weight children on a number of outcome measures at seven and 8 years of age. Results revealed that children born within the lowest birth weight category produced the most adverse findings, from both a statistical and clinical standpoint, on measures of cognitive ability, academic achievement, speech, language, auditory processing, and visual–motor integration.

Preterm Birth and Maternal Mental Health: Longitudinal Trajectories and Predictors

OBJECTIVE

To examine trajectories of psychological distress in mothers of children born very preterm (VPT, <30 weeks gestation) and full term from 2 to 13 years after the birth, and examine predictors of maternal psychological distress over time within the VPT group.

METHODS

Mothers of children born VPT (n = 159) and full term (n = 71) completed questionnaires assessing their psychological distress when their child was 2, 7, and 13 years of age. Mixed models were used to examine differences between groups in maternal psychological distress over time. Family social risk, child neonatal medial risk, child sex, multiple pregnancy, and child's neurodevelopmental impairment in early childhood were examined as potential predictors of maternal psychological distress within the VPT group.

RESULTS

Mothers of children born VPT displayed elevated psychological distress compared with mothers of full-term children, and this difference was consistent over time. Higher family social risk was associated with elevated maternal psychological distress throughout childhood across all time-points. There was evidence that mothers of children at higher neonatal medical risk displayed increasing psychological distress over time.

CONCLUSIONS

Mothers of children born VPT show prolonged psychological distress. Mothers from socially disadvantaged background and those whose child has neonatal medical complications may require extensive support to prevent prolonged psychological distress and promote optimal outcomes for children and families.

Executive function deficits in children born preterm or at low birthweight: a meta-analysis

AIM

To investigate the magnitude of executive function deficits and their dependency on gestational age, sex, age at assessment, and year of birth for children born preterm and/or at low birthweight.

METHOD

PubMed, PsychINFO, Web of Science, and ERIC were searched for studies reporting on executive functions in children born preterm/low birthweight and term controls born in 1990 and later, assessed at a mean age of 4 years or higher. Studies were included if five or more studies reported on the same executive function measures.

RESULTS

Thirty-five studies (3360 children born preterm/low birthweight, 2812 controls) were included. Children born preterm/low birthweight performed 0.5 standardized mean difference (SMD) lower on working memory and cognitive flexibility and 0.4 SMD lower on inhibition. SMDs for these executive functions did not significantly differ from each other. Meta-regression showed that heterogeneity in SMDs for working memory and inhibition could not be explained by study differences in gestational age, sex, age at assessment, or year of birth.

INTERPRETATION

Children born preterm/low birthweight since 1990 perform half a SMD below term-born peers on executive function, which does not seem to improve with more recent advances in medical care or with increasing age.

WHAT THIS PAPER ADDS

Children born preterm/low birthweight perform below term-born children on core executive functions. Lower gestational age or male sex are not risk factors for poorer executive functions. Executive function difficulties in children born preterm/low birthweight remain stable across childhood. Executive function difficulties are similar for children born recently and children born in earlier eras.

Association of Preterm Birth and Low Birth Weight With Romantic Partnership, Sexual Intercourse, and Parenthood in Adulthood: A Systematic Review and Meta-analysis

IMPORTANCE

Social relationships are important determinants of well-being, health, and quality of life. There are conflicting findings regarding the association between preterm birth or low birth weight and experiences of social relationships in adulthood.

OBJECTIVE

To systematically investigate the association between preterm birth or low birth weight and social outcomes in adulthood.

DATA SOURCES

PubMed, PsycINFO, Web of Science, and Embase were searched for peer-reviewed articles published through August 5, 2018.

STUDY SELECTION

Prospective longitudinal and registry studies reporting on selected social outcomes in adults who were born preterm or with low birth weight (mean sample age ≥18 years) compared with control individuals born at term.

DATA EXTRACTION AND SYNTHESIS

The meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The data were collected and extracted by 2 independent reviewers. Pooled analyses were based on odds ratios (ORs) with 95% confidence intervals and Hedges g, which were meta-analyzed using random-effects models.

MAIN OUTCOMES AND MEASURES

Ever being in a romantic partnership, ever having experienced sexual intercourse, parenthood, quality of romantic relationship, and peer social support.

RESULTS

Twenty-one studies were included of the 1829 articles screened. Summary data describing a maximum of 4 423 798 adult participants (179 724 preterm or low birth weight) were analyzed. Adults born preterm or with low birth weight were less likely to have ever experienced a romantic partnership (OR, 0.72; 95% CI, 0.64-0.81), to have had sexual intercourse (OR, 0.43; 95% CI, 0.31-0.61), or to have become parents (OR, 0.77; 95% CI, 0.65-0.91) than adults born full-term. A dose-response association according to degree of prematurity was found for romantic partnership and parenthood. Overall, effect sizes did not differ with age and sex. When adults born preterm or with low birth weight were in a romantic partnership or had friends, the quality of these relationships was not poorer compared with adults born full-term.

CONCLUSIONS AND RELEVANCE

These findings suggest that adults born preterm or with low birth weight are less likely to experience a romantic partnership, sexual intercourse, or to become parents. However, preterm birth or low birth weight does not seem to impair the quality of relationships with partners and friends. Lack of sexual or partner relationships might increase the risk of decreased well-being and poorer physical and mental health.

Developmental outcomes of very preterm children with high parental education level

BACKGROUND

Compared to their term-born peers, children born very preterm are at risk for poorer cognitive, academic and behavioral outcomes, however this finding may have been confounded by lower parental education level in the very preterm children. Studies that compare very preterm and term-born children with comparable (high) parental education level are needed to assess the true effect of very preterm birth on outcomes.

AIMS

To compare cognitive, academic and behavioral functioning in very preterm and term-born children of highly educated parents. To examine whether outcomes differ for children of whom one or both parents are highly educated.

STUDY DESIGN

Cross-sectional study with a term-born comparison group.

SUBJECTS

113 very preterm children and 38 term-born children aged 8-12 years old, with highly educated parents.

MEASURES

Cognitive functioning (Intelligence Quotient), academic functioning (arithmetic facts and reading) and parent and teacher rated behavioral functioning (attention, executive function, hyperactivity, and emotional, conduct and peer problems). Parental education was considered high when children had two highly educated parents or one highly- and one middle educated parent.

RESULTS

Very preterm children had significantly poorer cognitive (difference of 10 IQ points) and behavioral functioning than their term-born peers, but did not differ on academic functioning. Children with one highly educated parent performed poorer than children with two highly educated parents on most outcome measures.

CONCLUSIONS

Performance of very preterm children should be compared to term-born peers with parents having comparable educational levels for accurate assessment of outcomes. The number of highly educated parents also impacts outcomes.

Predicting text reading skills at age 8 years in children born preterm and at term

BACKGROUND

Children born preterm are at risk for developing reading difficulties and for decrements in other cognitive skills compared to children born at term.

AIMS

To assess how domains of function, often negatively impacted by preterm birth, predict reading development in children born preterm and at term.

STUDY DESIGN

Longitudinal descriptive cohort study.

SUBJECTS

Preterm (n = 48; gestational age 22-32 weeks, 30 males) and term (n = 41, 18 males) participants were assessed at age 6 years on a battery of verbal and non-verbal cognitive skills and reassessed at age 8 using the Gray Oral Reading Tests-5. Linear regressions assessed the contributions of phonological awareness, language, executive function, and non-verbal IQ at age 6 to reading outcome at age 8.

RESULTS

Children born preterm had lower scores than children born at term on all measures (Cohen's d from 0.46 to 1.08, all p < .05). Phonological awareness and language abilities predicted reading in both groups (accounting for 19.9% and 25.0% of variance, respectively, p < .001). Birth group did not moderate the association. By contrast, the association between executive function and non-verbal intelligence and reading outcome was moderated by birth group (interaction accounted for 3.9-6.7% of variance, respectively, p < .05). Positive predictions to reading from executive function and non-verbal IQ were found only in children born preterm.

CONCLUSIONS

Non-verbal cognitive skills improved the prediction of reading outcome only in the preterm group, suggesting that reading decrements represent a component of global deficits. These findings have implications for evaluation of children born preterm at school entry and treatment of reading difficulties.

Academic challenges for the preterm infant: Parent and educators' perspectives

BACKGROUND

Little is known of educators' knowledge of the impact of preterm birth on academic achievement and nothing is known of parental perspective of this knowledge.

AIMS

To examine the knowledge of the impact of preterm birth on academic achievement amongst Canadian educators, characterize educators' attitudes towards these challenges, and examine parental perspectives of the educational system for their preterm child.

STUDY DESIGN AND METHODS

This was a mixed methods study involving kindergarten to Grade 3 educators and parents of preterm children aged 4-8 years. Focus groups were conducted with 35 educators and surveys were collected from 138 educators and 174 parents. Thematic analysis was employed for focus group data and findings from surveys were summarized using descriptive statistics.

RESULTS

Themes identified from focus groups included: educators' knowledge was experiential, limited information sharing by parents, and lack of resources. No consensus existed amongst educators on facilitators or barriers in the educational system to help children born preterm. On the parent survey, parental disclosure of medical history was more frequent with lower gestational age. Most parents (94.9%, 130/137) advocated for extended neonatal follow-up and only 59.9% (82/137) expressed confidence that the school was meeting their child's needs. The educator survey confirmed these themes, except educators advocated for disclosure of the child's medical history (91.7%, 100/109). Additional qualifications and experience enhanced educators' knowledge, being a parent of a child born preterm did not.

CONCLUSION

Educators are unprepared to address the academic challenges for the preterm child and training is needed. Parents and providers need to be prepared to advocate.

Aberrant structural and functional connectivity and neurodevelopmental impairment in preterm children

Background

Despite advances in antenatal and neonatal care, preterm birth remains a leading cause of neurological disabilities in children. Infants born prematurely, particularly those delivered at the earliest gestational ages, commonly demonstrate increased rates of impairment across multiple neurodevelopmental domains. Indeed, the current literature establishes that preterm birth is a leading risk factor for cerebral palsy, is associated with executive function deficits, increases risk for impaired receptive and expressive language skills, and is linked with higher rates of co-occurring attention deficit hyperactivity disorder, anxiety, and autism spectrum disorders. These same infants also demonstrate elevated rates of aberrant cerebral structural and functional connectivity, with persistent changes evident across advanced magnetic resonance imaging modalities as early as the neonatal period. Emerging findings from cross-sectional and longitudinal investigations increasingly suggest that aberrant connectivity within key functional networks and white matter tracts may underlie the neurodevelopmental impairments common in this population.

Main body

This review begins by highlighting the elevated rates of neurodevelopmental disorders across domains in this clinical population, describes the patterns of aberrant structural and functional connectivity common in prematurely-born infants and children, and then reviews the increasingly established body of literature delineating the relationship between these brain abnormalities and adverse neurodevelopmental outcomes. We also detail important, typically understudied, clinical, and social variables that may influence these relationships among preterm children, including heritability and psychosocial risks.

Conclusion

Future work in this domain should continue to leverage longitudinal evaluations of preterm infants which include both neuroimaging and detailed serial neurodevelopmental assessments to further characterize relationships between imaging measures and impairment, information necessary for advancing our understanding of modifiable risk factors underlying these disorders and best practices for improving neurodevelopmental trajectories in this high-risk clinical population.

Preterm Birth/Low Birth Weight and Markers Reflective of Wealth in Adulthood: A Meta-analysis

CONTEXT

Preterm birth and/or low birth weight (PT/LBW) increases the risk of cognitive deficits, which suggests an association between PT/LBW and lower wealth in adulthood. Nevertheless, studies have revealed inconsistent findings so far.

OBJECTIVE

To systematically investigate whether PT/LBW is associated with markers of adulthood wealth.

DATA SOURCES

We searched Medline, PubMed, PsycINFO, Web of Science, and Embase.

STUDY SELECTION

Prospective longitudinal and registry studies containing reports on selected wealth-related outcomes in PT/LBW-born adults compared with term-born controls.

DATA EXTRACTION

Two independent reviewers extracted data on educational qualifications, employment rates, social benefits, and independent living.

RESULTS

Of 1347 articles screened, 23 studies met the inclusion criteria. PT/LBW was associated with decreased likelihood of attainment of higher education qualifications (odds ratio [OR] = 0.74; 95% confidence interval [CI] = 0.69-0.80), lower employment rate (OR = 0.83; 95% CI = 0.74-0.92), and increased likelihood of receiving social benefits (OR = 1.25; 95% CI = 1.09-1.42). A dose-response relationship according to gestational age was only found for education qualifications. PT/LBW-born adults did not differ significantly from those born at term in independent living.

LIMITATIONS

There was high heterogeneity between studies. There were unequal numbers of studies from different regions in the world.

CONCLUSIONS

PT/LBW is associated with lower educational qualifications, decreased rate of employment, and an increased rate of receipt of social benefits in adulthood. Low educational qualifications were most prevalent in those born very preterm and consistent across geographic regions. However, the findings are less clear for independent living.

Infants born preterm, stress, and neurodevelopment in the neonatal intensive care unit: might music have an impact?

AIM

The neonatal intensive care unit (NICU) provides life-saving medical care for an increasing number of newborn infants each year. NICU care, while lifesaving, does have attendant consequences which can include repeated activation of the stress response and reduced maternal interaction, with possible negative long-term impacts on brain development. Here we present a neuroscientific framework for considering the impact of music on neurodevelopment in the NICU of infants born preterm and evaluate current literature on the use of music with this population to determine what is most reliably known of the physiological effects of music interventions.

METHOD

Using online academic databases we collected relevant, experimental studies aimed at determining effects of music listening in infants in the NICU. These articles were evaluated for methodological rigor, ranking the 10 most experimentally stringent as a representative sample.

RESULTS

The selected literature seems to indicate that effects are present on the cardio-pulmonary system and behavior of neonates, although the relative effect size remains unclear.

INTERPRETATION

These findings indicate a need for more standardized longitudinal studies aimed at determining not only whether NICU music exposure has beneficial effects on the cardio-pulmonary system, but also on the hypothalamic-pituitary-adrenal axis, brain structures, and cognitive behavioral status of these children as well.

WHAT THIS PAPER ADDS

Provides a neuroscience framework for considering how music might attenuate stress in neonatal intensive care unit (NICU) infants. Considers how repeated stress may cause negative neurodevelopmental impacts in infants born preterm. Posits epigenetics can serve as a mechanistic pathway for music moderating the stress response.

Maternal intelligence quotient (IQ) predicts IQ and language in very preterm children at age 5 years

BACKGROUND

Sociodemographic factors are linked to cognitive outcomes in children born very preterm (VPT; ≤30 weeks gestation). The influence of maternal intellectual ability, a heritable trait, is unknown. Also undetermined is the extent to which associations between maternal and child intellectual ability vary according to parenting behaviors that target cognitive stimulation in the home.

METHODS

At age 5 years, 84 VPT and 38 demographically matched full-term (FT) children underwent neurodevelopmental assessment. Children's intellectual ability was assessed using The Wechsler Preschool Primary Scale of Intelligence-III, and language was assessed with the Clinical Evaluation of Language Fundamentals Preschool-2. The Wechsler Test of Adult Reading estimated maternal intellectual ability. The StimQ-Preschool questionnaire provided a measure of cognitive stimulation in the home. Linear mixed-effects models examined independent effects and interactions between maternal intellectual ability and cognitive stimulation on children's outcomes.

RESULTS

After covariate adjustment, maternal intellectual ability was associated with child intellectual (p < .001) and language (p = .002) abilities. Stronger associations were observed in FT mother-child dyads (B = .63, p = .04) than VPT dyads (B = .42, p = .01). Mothers of VPT children reported lower levels of Parental Involvement in Developmental Advance (p = .007) and Parental Verbal Responsiveness (p = .04). Group differences in Parental Involvement in Developmental Advance, but not Parental Verbal Responsivity, persisted after adjusting for social background (p = .03). There was no evidence of an interaction between maternal intellectual ability and Parental Involvement in Developmental Advance (p = .34). Instead, maternal intellectual ability (p < .001) and Parental Involvement in Developmental Advance (p = .05) independently predicted VPT children's outcomes.

CONCLUSIONS

Maternal intellectual ability is an important trait linked to VPT and FT children's intellectual and language outcomes. Prematurity increases variation in the heritability of intellectual ability and shifts children from the expected range based on maternal ability. Parental involvement in activities that help children master new skills may promote cognitive development in VPT children born to mothers of lower intellectual ability.

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.

Developmental outcomes and physical activity behaviour in children post major surgery: an observational study

Background

Infants may be at neurodevelopmental risk from adverse events arising in the neonatal period. This study aimed to investigate the developmental outcomes and physical activity behaviours of term infants after neonatal major surgery, at age three years.

Methods

This prospective study enrolled infants who underwent major surgery in their first 90 days, between August 2006 and December 2008. Developmental status was assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Physical activity and sedentary behaviour (i.e. small screen recreation) (SSR) were assessed using the Preschool-Age Physical Activity Questionnaire (Pre-PAQ). Activity (moving between slow to fast pace) and SSR were reported for a 3-day period.

Results

One hundred and thirty five children (68 major surgery, 67 control) were assessed, using both measures, at age three years. Both groups were within the average range across all domains of the BSID-III although the surgical group was significantly below the controls for cognition (t = −3.162, p = 0.002) receptive language (t = −3.790, p < 0.001) and fine motor skills (t = −2.153, p = 0.03). Mean activity time for the surgical group was 191 mins.day⁻¹, and 185 mins.day-1 for controls. Mean SSR time was 77 mins.day⁻¹, and 83 mins.day⁻¹ for the respective groups. There was no significant difference between groups for either physical activity (p = 0.71) or SSR time (p = 0.49).

Conclusions

By age three, children who had major surgery in infancy are developmentally normal but have not quite caught up with their peer group in cognitive, receptive language and fine motor skill domains. Both groups met recommended 3 h of daily physical activity but exceeded 60-min SSR time recommended for preschool-age children.