Trajectories of problem behaviors from 4 to 23 years in former preterm infants

Associations of behavioral problems with white matter circuits connecting to the frontal lobes in school-aged children born at term and preterm

Introduction

This study investigated whether behavioral problems in children were associated with fractional anisotropy (FA) of white matter tracts connecting from other brain regions to right and left frontal lobes. We considered internalizing and externalizing behavioral problems separately and contrasted patterns of associations in children born at term and very preterm.

Methods

Parents completed the Child Behavior Checklist/6-18 questionnaire to quantify behavioral problems when their children were age 8 years (N=36 FT and 37 PT). Diffusion magnetic resonance scans were collected at the same age and analyzed using probabilistic tractography. We used multiple linear regression to investigate the strength of association between age-adjusted T-scores of internalizing and externalizing problems and mean fractional anisotropy (mean-FA) of right and left uncinate, arcuate, and anterior thalamic radiations, controlling for birth group and sex.

Results

Regression models predicting internalizing T-scores from mean-FA found significant group-by-tract interactions for the left and right arcuate and right uncinate. Internalizing scores were negatively associated with mean-FA of left and right arcuate only in children born at term (pleft AF =0.01, pright AF =0.01). Regression models predicting externalizing T-scores from mean-FA found significant group-by-tract interactions for the left arcuate and right uncinate. Externalizing scores were negatively associated with mean-FA of right uncinate in children born at term (pright UF =0.01) and positively associated in children born preterm (pright UF preterm =0.01). Other models were not significant.

Conclusions

In this sample of children with scores for behavioral problems across the full range, internalizing and externalizing behavioral problems were negatively associated with mean-FA of white matter tracts connecting to frontal lobes in children born at term; externalizing behavioral problems were positively associated with mean-FA of the right uncinate in children born preterm. The different associations by birth group suggest that the neurobiology of behavioral problems differs in the two birth groups.

Preterm birth, birthweight, and subsequent risk for depression

An individual's birthweight, a marker of in utero exposures, was recently associated with certain psychiatric conditions. However, studies investigating the relationship between an individual's preterm birth status and/or birthweight and risk for depression during adulthood are sparse; we used data from the Women's Health Initiative (WHI) to investigate these potential associations. At study entry, 86,925 postmenopausal women reported their birthweight by category (<6 lbs., 6-7 lbs. 15 oz., 8-9 lbs. 15 oz., or ≥10 lbs.) and their preterm birth status (full-term or ≥4 weeks premature). Women also completed the Burnham screen for depression and were asked to self-report if: (a) they had ever been diagnosed with depression, or (b) if they were taking antidepressant medications. Linear and logistic regression models were used to estimate unadjusted and adjusted effect estimates. Compared to those born weighing between 6 and 7 lbs. 15 oz., individuals born weighing <6 lbs. (βadj = 0.007, P < 0.0001) and ≥10 lbs. (βadj = 0.006, P = 0.02) had significantly higher Burnam scores. Individuals born weighing <6 lbs. were also more likely to have depression (adjOR 1.21, 95% CI 1.11-1.31). Individuals born preterm were also more likely to have depression (adjOR 1.18, 95% CI 1.02-1.35); while attenuated, this association remained in analyses limited to only those reportedly born weighing <6 lbs. Our research supports the role of early life exposures on health risks across the life course. Individuals born at low or high birthweights and those born preterm may benefit from early evaluation and long-term follow-up for the prevention and treatment of mental health outcomes.

Associations of Behavioral Problems and White Matter Properties of the Cerebellar Peduncles in Boys and Girls Born Full Term and Preterm

Accumulating evidence suggests that the role of cerebellum includes regulation of behaviors; cerebellar impairment may lead to behavioral problems. Behavioral problems differ by sex: internalizing problems are more common in girls, externalizing problems in boys. Behavioral problems are also elevated in children born preterm (PT) compared to children born full term (FT). The current study examined internalizing and externalizing problems in 8-year-old children in relation to sex, birth-group, fractional anisotropy (FA) of the three cerebellar peduncles (superior, middle, and inferior), and interactions among these predictor variables. Participants (N = 78) were 44 boys (28 PT) and 34 girls (15 PT). We assessed behavioral problems via standardized parent reports and FA of the cerebellar peduncles using deterministic tractography. Internalizing problems were higher in children born PT compared to children born FT (p = .032); the interaction of sex and birth-group was significant (p = .044). When considering the contribution of the mean-tract FA of cerebellar peduncles to behavioral problems, there was a significant interaction of sex and mean-tract FA of the inferior cerebellar peduncle (ICP) with internalizing problems; the slope was negative in girls (p = .020) but not in boys. In boys, internalizing problems were only associated with mean-tract FA ICP in those born preterm (p = .010). We found no other significant associations contributing to internalizing or externalizing problems. Thus, we found sexual dimorphism and birth-group differences in the association of white matter metrics of the ICP and internalizing problems in school-aged children. The findings inform theories of the origins of internalizing behavioral problems in middle childhood and may suggest approaches to treatment at school age.

Preterm Birth, Developmental Smoke/Nicotine Exposure, and Life-Long Pulmonary Sequelae

This review delineates the main pulmonary issues related to preterm birth, perinatal tobacco/nicotine exposure, and its effects on offspring, focusing on respiratory health and its possible transmission to subsequent generations. We review the extent of the problem of preterm birth, prematurity-related pulmonary effects, and the associated increased risk of asthma later in life. We then review the impact of developmental tobacco/nicotine exposure on offspring asthma and the significance of transgenerational pulmonary effects following perinatal tobacco/nicotine exposure, possibly via its effects on germline epigenetics.

Association of Neonatal Pain-Related Stress and Parent Interaction With Internalizing Behaviors Across 1.5, 3.0, 4.5, and 8.0 Years in Children Born Very Preterm

IMPORTANCE

Internalizing (anxiety and/or depressive) behaviors are prevalent in children born very preterm (24-32 weeks' gestation). Procedural pain-related stress in the neonatal intensive care unit (NICU) is associated with long-term internalizing problems in this population; however, whether positive parenting during toddlerhood attenuates development of internalizing behaviors across childhood is unknown.

OBJECTIVE

To investigate whether neonatal pain-related stress is associated with trajectories of internalizing behaviors across 1.5, 3.0, 4.5, and 8.0 years, and whether supportive parenting behaviors and lower parenting stress at 1.5 and 3.0 years attenuate this association.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective longitudinal cohort study, preterm neonates (born at 24-32 weeks' gestation) were recruited from August 16, 2006, to September 9, 2013, with follow-up visits at ages 1.5, 3.0, 4.5, and 8.0 years. The study was conducted at BC Women's Hospital, Vancouver, Canada, with recruitment from a level III neonatal intensive care unit and sequential developmental assessments performed in a Neonatal Follow-up Program. Data analysis was performed from August to December 2021.

MAIN OUTCOMES AND MEASURES

Parental report of child internalizing behaviors on the Child Behavior Checklist at 1.5, 3.0, 4.5, and 8.0 years.

RESULTS

A total of 234 neonates were recruited, and 186 children (101 boys [54%]) were included in the current study across ages 1.5 (159 children), 3.0 (169 children), 4.5 (162 children), and 8.0 (153 children) years. After accounting for clinical factors associated with prematurity, greater neonatal pain-related stress was associated with more internalizing behaviors across ages (B = 4.95; 95% CI, 0.76 to 9.14). Higher parenting stress at age 1.5 years (B = 0.17; 95% CI, 0.11 to 0.23) and a less supportive parent environment (less sensitivity, structure, nonintrusiveness, nonhostility, and higher parenting stress; B = -5.47; 95% CI, -9.44 to -1.51) at 3.0 years were associated with greater internalizing problems across development to age 8.0 years.

CONCLUSIONS AND RELEVANCE

In this cohort study of children born very preterm, exposure to repetitive neonatal pain-related stress was associated with persistent internalizing behavior problems across toddlerhood to age 8.0 years. Supportive parenting behaviors during early childhood were associated with better long-term behavioral outcomes, whereas elevated parenting stress was associated with more child anxiety and/or depressive behaviors in this population. These findings reinforce the need to prevent pain in preterm neonates and inform future development of targeted parent-led behavioral interventions.

The Very Preterm Brain at Rest: Longitudinal Social-Cognitive Network Connectivity During Childhood

Very preterm (VPT: ≤32 weeks of gestational age) birth poses an increased risk for social and cognitive morbidities that persist throughout life. Resting-state functional network connectivity studies provide information about the intrinsic capacity for cognitive processing. We studied the following four social–cognitive resting-state networks: the default mode, salience, frontal-parietal and language networks. We examined functional connectivity using magnetoencephalography with individual head localization using each participant’s MRI at 6 (n = 40) and 8 (n = 40) years of age compared to age- and sex-matched full-term (FT) born children (n = 38 at 6 years and n = 43 at 8 years). VPT children showed increased connectivity compared to FT children in the gamma band (30–80 Hz) at 6 years within the default mode network (DMN), and between the DMN and the salience, frontal-parietal and language networks, pointing to more diffuse, less segregated processing across networks at this age. At 8 years, VPT children had more social and academic difficulties. Increased DMN connectivity at 6 years was associated with social and working memory difficulties at 8 years. Therefore, we suggest that increased DMN connectivity contributes to the observed emerging social and cognitive morbidities in school age.

Next generation strategies for preventing preterm birth

Preterm birth (PTB) is defined as delivery before 37 weeks of gestation. Globally, 15 million infants are born prematurely, putting these children at an increased risk of mortality and lifelong health challenges. Currently in the U.S., there is only one FDA approved therapy for the prevention of preterm birth. Makena is an intramuscular progestin injection given to women who have experienced a premature delivery in the past. Recently, however, Makena failed a confirmatory trial, resulting the Center for Drug Evaluation and Research's (CDER) recommendation for the FDA to withdrawal Makena's approval. This recommendation would leave clinicians with no therapeutic options for preventing PTB. Here, we outline recent interdisciplinary efforts involving physicians, pharmacologists, biologists, chemists, and engineers to understand risk factors associated with PTB, to define mechanisms that contribute to PTB, and to develop next generation therapies for preventing PTB. These advances have the potential to better identify women at risk for PTB, prevent the onset of premature labor, and, ultimately, save infant lives.

Maternal depressive symptoms, poverty, and young motherhood increase the odds of early depressive and anxiety disorders for children born prematurely

Children born preterm, compared to term, are at risk for behavioral problems. However, the prevalence and predictors of internalizing disorders among children born preterm are unclear. The purpose of this study was to identify the prevalence of depressive and anxiety disorders at 2 years of age among children born preterm and determine the extent to which poverty, maternal depressive symptoms, or young motherhood increase the likelihood of these disorders. Mothers and their infants (N = 105) were recruited from two neonatal intensive care units affiliated with a major U.S. university. A sociodemographic questionnaire, the Patient Health Questionnaire‐9, and the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition scale scores from the Preschool Child Behavior Checklist were used to measure primary variables. We examined mothers’ family satisfaction and quality of caregiving as well as children's degree of prematurity, morbidity, gender, cognitive functioning, and motor function as covariates. Fifteen percent of children met criteria for an anxiety disorder and another 15% for depression. Maternal depressive symptoms increased the odds of children developing both anxiety and depression, whereas young motherhood was associated with child anxiety and poverty with child depression. Results indicate the need for mental health assessment of children born preterm during their first 2 years of life and the importance of early therapeutic and tangible support to vulnerable mothers and children.

Early nutrition and white matter microstructure in children born very low birth weight

Infants born at very low birth weight (<1500 g) are vulnerable to nutritional deficits during their first postnatal month, which are associated with poor neurodevelopmental outcomes. Despite this knowledge, the impact of early postnatal nutrition on white matter microstructure in children born with very low birth weight has not been investigated. In this prospective cohort study, we employed a whole-brain approach to investigate associations between precise estimates of nutrient intake within the first postnatal month with white matter microstructure at 5 years of age. Detailed information about breastmilk, macronutrient and energy intakes during this period were prospectively recorded for all participants. Multi-shell diffusion and T1-weighted MRIs were acquired in 41 children (21 males; mean scan age: 5.75 ± 0.22 years; mean birth weight: 1028.6 ± 256.8 g). The diffusion tensor imaging and neurite orientation dispersion and density imaging models were used to obtain maps of fractional anisotropy, radial diffusivity, orientation dispersion and neurite density indices. Tract-based spatial statistics was used to test associations between metrics of white matter microstructure with breastmilk, macronutrient (protein, lipids and carbohydrate) and energy intake. Associations between white matter microstructure and cognitive outcomes were also examined. Compared to children who did not meet enteral feeding recommendations, those who achieved enteral protein, lipid and energy recommendations during the first postnatal month showed improved white matter maturation at 5 years. Among the macronutrients, greater protein intake contributed most to the beneficial effect of nutrition, showing widespread increases in fractional anisotropy and reductions in radial diffusivity. No significant associations were found between white matter metrics with breastmilk or carbohydrate intake. Voxel-wise analyses with cognitive outcomes revealed significant associations between higher fractional anisotropy and neurite density index with higher processing speed scores. Lower radial diffusivity and orientation dispersion index were also associated with improved processing speed. Our findings support the long-term impacts of early nutrition on white matter microstructure, which in turn is related to cognitive outcomes. These results provide strong support for early postnatal nutritional intervention as a promising strategy to improve long-term cognitive outcomes of infants born at very low birth weight.

Negative affectivity moderated by preterm birth predicted toddlers' behavior problems

OBJECTIVE

The present study aimed to examine the predictive effect of temperament moderated by preterm childbirth on behavioral problems in toddlerhood.

METHOD

The sample comprised 100 toddlers of 18-36 months of chronological age and their mothers. They were divided into two groups: 50 toddlers born preterm and admitted to the Neonatal Intensive Care Unit (PT group), and 50 toddlers born full-term (FT group) and recruited from day-care centers. Mothers completed questionnaires about toddlers' temperament and behavior. The Early Childhood Behavior Questionnaire was used to assess temperament, and the Child Behavior Checklist (CBCL 1¹/²-5) to evaluate the total, internalizing, and externalizing behavior problems. Multiple regression analysis was performed to examine the moderation effects of preterm childbirth and temperament factors after controlling for toddlers' age and socioeconomic level.

RESULTS

There was a moderation effect between preterm childbirth and temperament. Temperament with more Negative Affectivity, moderated by preterm birth, and less Effortful Control explained the total, internalizing, and externalizing behavior problems.

CONCLUSION

The findings contribute to a better understanding of the impact of preterm childbirth and the dispositional traits of temperament on behavioral problems of toddlers born preterm.

Executive function deficits mediate the association between very preterm birth and behavioral problems at school-age

BACKGROUND & AIMS

Children and adolescents born very preterm are at increased risk to develop executive function deficits and to suffer from social, emotional and attentional problems. This study investigated whether executive function deficits contribute to behavioral problems in children and adolescents born very preterm at school-age.

STUDY DESIGN

Thirty-eight children and adolescents born very preterm and 41 age-matched term-born peers were assessed at a mean age of 12.9 (±1.8) years with a comprehensive battery of executive function tests, including working memory, planning, cognitive flexibility, and verbal fluency. A composite score was calculated to reflect overall executive function abilities. To assess behavioral problems, parents completed the Strengths and Difficulties Questionnaire (SDQ). Mediation analysis was applied to quantify the effect of preterm birth on behavioral problems with executive function abilities as a mediating variable.

RESULTS

Executive function abilities were poorer in the very preterm compared to the term-born group (d = 0.62, p = .005) and the parents of very preterm children reported more behavioral problems on the SDQ Total Difficulties Score (d = 0.54, p = .01). The effect of birth status on behavioral problems was significantly mediated by executive function abilities while adjusting for age at assessment, sex, and socioeconomic status (F(2, 76) = 6.42, p = .002, R² = 0.14).

CONCLUSION

Results from this study suggest that the increase in behavioral symptoms in very preterm children at school-age compared to term-born peers may partly be explained by their executive function deficits. These findings highlight the importance of continuously monitoring the development of children born very preterm to provide optimal care as they grow up.

Effortful control and attention as predictors of cognition in children born preterm

BACKGROUND

Preterm childbirth increases the risk of developmental problems. The aim of the present study was to examine the effects of temperament and attention on the cognition of school-age children who were born preterm, controlling for socioeconomic variables.

MATERIAL AND METHODS

The sample was composed of 50 six-year-old children who were born preterm with very low birth weight. The children were evaluated using the Wechsler Intelligence Scale for Children (WISC-III) and the Cancellation Attention Test. The mothers were interviewed using the Children's Behavior Questionnaire (CBQ). Statistical multiple linear regression analyses were performed.

RESULTS

70% of the children presented average or above-average full intellectual quotient (IQ). In the attention total score, 74% of the children were also within the average range or above. High verbal IQ associated with high maternal schooling explained 73% variability of the full IQ. High attention and maternal schooling, associated with children's temperament with more effortful control, explained 35% variability of the verbal IQ. High attention, associated with high maternal schooling and socioeconomic level, explained 37% variability of the performance IQ. The neonatal clinical variables (gestational age, birth weight, 5th-minute Apgar, and length of stay in neonatal intensive care unit (NICU) and hospital) were not predictors of cognitive outcomes.

CONCLUSION

The majority of the children who were born preterm presented average or above-average cognitive and attentional performances at school age, demonstrating potential resources for learning. Taken together, attention and temperament, associated with maternal schooling and socioeconomic status, were predictors of cognitive outcomes of children born preterm at school age.

Development and predictors of childhood mental health problems in former extremely preterm infants

OBJECTIVE

To investigate development and predictors of mental health problems from five to eleven years of age in children born extremely preterm (EP).

METHOD

In a national Norwegian cohort of children born before a gestational age of 28 weeks or with a birthweight <1000 g mental health was assessed by parents at five and eleven years of age using The Strengths and Difficulties Questionnaire. A Total Difficulties Score ≥ 90th percentile (TDS90) for a reference group was used as a measure of a mental health problem. Of 338 eligible EP children, 162 (48%) attended at both ages.

RESULTS

The rate of TDS90 was 52 (32%) at five and 37 (23%) at eleven years of age (p = 0.025). Of the 52 children with TDS90 at five years, 25 had TDS90 at eleven years of age, and of 37 children with TDS90 at eleven, 25 had TDS90 at five years of age. Mental health problems and an IQ of 70-84 at five years were independent predictors of TDS90 at eleven years of age.

CONCLUSION

The rate of mental health problems decreased from five to eleven years, but individual stability was moderate. Mental health problems and intellectual function in the lower normal range at preschool age were independent predictors of later mental health problems.

Persistence of Effects of VLBW/PT Birth Status and Maternal Emotional Availability (EA) on Child EA Trajectories

Few studies have examined the longitudinal impact of birth status on the infant-mother relationship and on children's socio-emotional development. In the present study we investigated developmental patterns of such relationships [using the Emotional Availability (EA) Scales] in fullterm and VLBW/PT infants from infancy to emerging school age. Our objectives were to: (a) model the developmental trajectories of EA dimensions (maternal sensitivity, structuring, non-hostility; child responsiveness, involvement) in a VLBW/PT and fullterm sample, (b) identify potential effects of VLBW/PT status on these trajectories, and (c) determine whether the effects of VLBW/PT status on children's socio-emotional development (child EA) remained after accounting for the effect of maternal EA. Child-mother dyads (n = 109) were observed in home-based interactions (face-to-face and free play) when children were 6, 12, 18, and 57-months-old in fullterm (37-41 weeks, >2500 g; n = 48) and healthy VLBW/PT (26-32 weeks gestation, birth weight 800-1500 g, corrected for gestational age; n = 61) children. Developmental trajectories of maternal and child EA were assessed using multilevel growth modeling in Mplus. Results indicated that, even after controlling for maternal EA, there was a persistent negative effect of VLBW/PT birth status on child EA trajectories. Both initially and over time, VLBW/PT infants lagged behind their fullterm counterparts on levels of responsiveness and involvement with mothers. There was also a persistent positive effect of maternal EA (sensitivity and structuring) on child EA trajectories. Higher average levels of maternal sensitivity and structuring across time were also associated with higher and persistent levels of child responsiveness and involvement of their mothers. Importantly, results held after modeling both effects together, and after controlling for maternal education and child gender. Our results have implications for VLBW/PT children's development, the parent-child relationship, and integrating family level factors and relationship dimensions in early prevention and intervention programs.

Long-Term Effects of Prematurity, Cumulative Medical Risk, and Proximal and Distal Social Forces on Individual Differences in Diurnal Cortisol at Young Adulthood

This study examined the effects of prematurity, cumulative medical risk, and proximal and distal social forces on individual differences in the activity of the hypothalamic-pituitary-adrenal (HPA) axis in young adulthood. A prospective sample of 149 infants born healthy preterm (PT; n = 22), sick PT ( n = 93, medical illness, neurological illness, small for gestational age), and full term ( n = 34) was recruited from a Level III neonatal intensive care unit in southern New England between 1985 and 1989 and followed to age 23 years. Cumulative medical risk was indexed across seven assessment waves (spanning 17 years) using medical and neurological health status at birth, toddlerhood (ages 18 and 30 months), childhood (ages 4 and 8 years), and adolescence (ages 12 and 17 years). Distal risk included socioeconomic status (SES) at birth. Proximal social factors were indexed from assessments of the home environment and measures of child vulnerability and maternal self-esteem, involvement, and control style from birth, 4 years, 8 years, and 12 years. At age 23 years, five saliva samples were collected upon awakening, 45 min after waking, 4 hr after waking, 8 hr after waking, and bedtime (later assayed for cortisol). Results reveal effects of cumulative medical risk on the diurnal pattern of HPA axis activity, with moderating effects of SES and proximal social factors. Findings are discussed in terms of implications for contemporary theories related to developmental sensitivity and susceptibility to context and the developmental origins of health and disease theory.