Antenatal antecedents of cognitive impairment at 24 months in extremely low gestational age newborns

Association of maternal pre-pregnancy or first trimester body mass index with neurodevelopmental impairment or death in extremely low gestational age neonates

OBJECTIVE

To compare the rates of death or survival with severe neurodevelopmental impairment (sNDI) at 2 years among extremely preterm infants in relation to pre-pregnancy or first-trimester maternal body mass index (BMI).

METHODS

This retrospective cohort study included extremely preterm infants (gestational age 220/7-266/7 weeks). The study was conducted at National Institute of Child Health and Human Development Neonatal Research Network sites. The primary outcome was death or sNDI at 2 years.

RESULTS

Data on the primary outcome were available for 1208 children. Death or sNDI was not different among the three groups: 54.9% in normal, 56.1% in overweight, and 53.4% in obese group (p = 0.39). There was no significant difference in mortality, sNDI, moderate/severe cerebral palsy, Bayley Scales of Infant Development (BSID)-III cognitive composite score <70, BSID-III language composite score <70 in adjusted models.

CONCLUSION

Neurodevelopmental outcome was not significantly associated with maternal pre-pregnancy BMI among extreme preterm infants.

Sex Differences in Autistic Youth Born Extremely Preterm

PURPOSE

To evaluate sex differences in autistic traits in youth born extremely preterm (EP; 23-27 weeks) who were later diagnosed with autism spectrum disorder (ASD) at 10-years.

METHOD

A longitudinal cohort design from the Extremely Low Gestational Age Newborn Study (ELGAN) followed N = 857 EP infants from birth through 10-years. EP infants later diagnosed with ASD (N = 61, 20 females) participated in the study. Group differences were evaluated via inferential and Bayesian statistics (values > 1 suggest evidence for alternate hypothesis) on ASD screeners (M-CHAT at 2-years, SCQ and SRS-2 at 10-years), and gold-standard diagnostic measures (ADOS-2, ADI-R) at 10-years.

RESULTS

Males scored significantly higher than females on measures of Social Affect from the ADOS-2, t(34.27)=-2.20, BF10 = 2.33, and measures of Repetitive and Restricted Behaviors from the ADI-R, t(40.52)=-2.85, BF10 = 5.26. Bayesian estimates suggested marginal evidence for sex differences in Nonverbal Communication, t(30.66)=-1.81, BF10 = 1.25, and Verbal Communication, t(24.64)=-1.89, BF10 = 1.39, from the ADI-R, wherein males scored higher than females. No statistically significant sex differences were identified on any of the ASD screeners at 2 (M-CHAT) or 10 years (SCQ). No significant sex differences were observed on any subscales of the SRS at 10 years.

CONCLUSIONS

EP autistic males present with more autistic traits than EP autistic females on gold-standard diagnostic measures of autism at 10-years of age, despite not presenting with higher autistic traits on screeners at either age. These results align with sex differences observed in full-term, autistic youth. These results suggest ASD screeners may under identify autism in EP youth, particularly females.

Placental fetal vascular malperfusion, neonatal neurologic morbidity, and infant neurodevelopmental outcomes: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the association of placental fetal vascular malperfusion lesions with neonatal brain injury and adverse infant neurodevelopmental outcomes.

DATA SOURCES

PubMed and Medline, Scopus, and Cochrane databases were searched from inception to July 2022.

STUDY ELIGIBILITY CRITERIA

We included cohort and case-control studies reporting the associations of fetal vascular malperfusion lesions with neonatal encephalopathy, perinatal stroke, intracranial hemorrhage, periventricular leukomalacia, and infant neurodevelopmental and cognitive outcomes.

METHODS

Data were analyzed by including fetal vascular malperfusion lesions as an exposure variable and brain injuries or neurodevelopmental impairment as outcomes using random-effects models. The effect of moderators, such as gestational age or study type, was assessed by subgroup analysis. Study quality and risk of bias were assessed by applying the Observational Study Quality Evaluation method.

RESULTS

Out of the 1115 identified articles, 26 were selected for quantitative analysis. The rates of neonatal central nervous system injury (neonatal encephalopathy or perinatal stroke) in term or near-term infants were more common among fetal vascular malperfusion cases (n=145) than among controls (n=1623) (odds ratio, 4.00; 95% confidence interval, 2.72-5.90). In premature deliveries, fetal vascular malperfusion lesions did not influence the risk of intracranial hemorrhage or periventricular leukomalacia (odds ratio, 1.40; 95% confidence interval, 0.90-2.18). Fetal vascular malperfusion-associated risk of abnormal infant neurodevelopmental outcome (314 fetal vascular malperfusion cases and 1329 controls) was modulated by gestational age being higher in term infants (odds ratio, 5.02; 95% confidence interval, 1.59-15.91) than in preterm infants (odds ratio, 1.70; 95% confidence interval, 1.13-2.56). Abnormal infant cognitive development and mental development were more common among fetal vascular malperfusion cases (n=241) than among controls (n=2477) (odds ratio, 2.14; 95% confidence interval, 1.40-3.27). The type of study (cohort vs case-control) did not influence the association between fetal vascular malperfusion and subsequent infant brain injury or abnormal neurodevelopmental outcome.

CONCLUSION

The findings of cohort and case-control studies indicate a considerable association between fetal vascular malperfusion placental lesions and increased risk of brain injury in term neonates, and neurodevelopmental impairment in both term and preterm infants. A diagnosis of placental fetal vascular malperfusion should be taken into consideration by both pediatricians and neurologists during the follow-up of infants at risk of adverse neurodevelopmental outcomes.

Maternal pre-pregnancy obesity affects the uncinate fasciculus white matter tract in preterm infants

Background

A growing body of evidence suggests an association between a higher maternal pre-pregnancy body mass index (BMI) and adverse long-term neurodevelopmental outcomes for their offspring. Despite recent attention to the effects of maternal obesity on fetal and neonatal brain development, changes in the brain microstructure of preterm infants born to mothers with pre-pregnancy obesity are still not well understood. This study aimed to detect the changes in the brain microstructure of obese mothers in pre-pregnancy and their offspring born as preterm infants using diffusion tensor imaging (DTI).

Methods

A total of 32 preterm infants (born to 16 mothers with normal BMI and 16 mothers with a high BMI) at <32 weeks of gestation without brain injury underwent brain magnetic resonance imaging at term-equivalent age (TEA). The BMI of all pregnant women was measured within approximately 12 weeks before pregnancy or the first 2 weeks of gestation. We analyzed the brain volume using a morphologically adaptive neonatal tissue segmentation toolbox and calculated the major white matter (WM) tracts using probabilistic maps of the Johns Hopkins University neonatal atlas. We investigated the differences in brain volume and WM microstructure between preterm infants of mothers with normal and high BMI. The DTI parameters were compared among groups using analysis of covariance adjusted for postmenstrual age at scan and multiple comparisons.

Results

Preterm infants born to mothers with a high BMI showed significantly increased cortical gray matter volume (p = 0.001) and decreased WM volume (p = 0.003) after controlling for postmenstrual age and multiple comparisons. We found a significantly lower axial diffusivity in the uncinate fasciculus (UNC) in mothers with high BMI than that in mothers with normal BMI (1.690 ± 0.066 vs. 1.762 ± 0.101, respectively; p = 0.005).

Conclusion

Our study is the first to demonstrate that maternal obesity impacts perinatal brain development patterns in preterm infants at TEA, even in the absence of apparent brain injury. These findings provide evidence for the detrimental effects of maternal obesity on brain developmental trajectories in offspring and suggest potential neurodevelopmental outcomes based on an altered UNC WM microstructure, which is known to be critical for language and social-emotional functions.

The contributions of parental lactation on offspring development: It's not udder nonsense!

The Developmental Origins of Health and Disease (DOHaD) hypothesis describes how maternal stress exposures experienced during critical periods of perinatal life are linked to altered developmental trajectories in offspring. Perinatal stress also induces changes in lactogenesis, milk volume, maternal care, and the nutritive and non-nutritive components of milk, affecting short and long-term developmental outcomes in offspring. For instance, selective early life stressors shape the contents of milk, including macro/micronutrients, immune components, microbiota, enzymes, hormones, milk-derived extracellular vesicles, and milk microRNAs. In this review, we highlight the contributions of parental lactation to offspring development by examining changes in the composition of breast milk in response to three well-characterized maternal stressors: nutritive stress, immune stress, and psychological stress. We discuss recent findings in human, animal, and in vitro models, their clinical relevance, study limitations, and potential therapeutic significance to improving human health and infant survival. We also discuss the benefits of enrichment methods and support tools that can be used to improve milk quality and volume as well as related developmental outcomes in offspring. Lastly, we use evidence-based primary literature to convey that even though select maternal stressors may modulate lactation biology (by influencing milk composition) depending on the severity and length of exposure, exclusive and/or prolonged milk feeding may attenuate the negative in utero effects of early life stressors and promote healthy developmental trajectories. Overall, scientific evidence supports lactation to be protective against nutritive and immune stressors, but the benefits of lactation in response to psychological stressors need further investigation.

Early Growth and Cognitive Development in Children Born Preterm: Relevance of Maternal Body Mass Index

OBJECTIVE

Maternal prepregnancy body mass index (BMI) represents a surrogate marker of fetal exposures to the maternal metabolism during pregnancy. Yet, it remains poorly understood whether this marker indicates risk of altered trajectories in postnatal growth and development in children born preterm. This study aimed to determine whether maternal prepregnancy BMI is associated with altered growth and development in children born preterm.

STUDY DESIGN

A retrospective cohort study evaluated prepregnancy BMI as the exposure for childhood outcomes using linear regression and mixed effects models. The 38 children included in this follow-up evaluation originally participated in a prospective, observational cohort study to determine longitudinal levels of lipid species in preterm human milk expressed by women who delivered prior to 32 weeks. Childhood outcomes in this study were anthropometric measures during hospitalization (n = 38), after discharge through 36 months (n = 34) and Bayley-III developmental scores through 18 months corrected age (n = 26).

RESULTS

In 38 children born prior to 32 weeks, higher maternal prepregnancy BMI was independently associated with higher preterm infant growth velocity during hospitalization, but not associated with in-hospital change in length or head circumference and/or postdischarge growth. In univariate linear regression models, higher maternal BMI was associated with lower cognitive scores at 18 months corrected age. This significant association remained in an adjusted model accounting for relevant influences on early childhood development.

CONCLUSION

Increasing maternal prepregnancy BMI may reflect risk of altered growth and cognitive development in children born preterm.

KEY POINTS

· Maternal BMI was associated with early preterm infant weight gain.. · Maternal BMI was not associated with postdischarge growth.. · Increased maternal BMI may be associated with lower cognitive function scores in offspring..

Psychiatric Outcomes, Functioning, and Participation in Extremely Low Gestational Age Newborns at Age 15 Years

OBJECTIVE

To evaluate the prevalence, co-occurrence, sex differences, and functional correlates of DSM-5 psychiatric disorders in 15-year-old adolescents born extremely preterm.

METHOD

The Extremely Low Gestational Age Newborns (ELGAN) Study is a longitudinal study of children born <28 weeks gestation. At age 15, 670 adolescents completed the Mini-International Neuropsychiatric Interview for Children and Adolescents (MINI-KID), the Youth Self-Report, a disability scale of participation in social roles, and cognitive testing. Parents completed a family psychiatric history questionnaire.

RESULTS

The most prevalent psychiatric disorders were anxiety, attention-deficit/hyperactivity disorder, and major depression. More girls met criteria for anxiety than boys. Though 66% of participants did not meet criteria for a psychiatric disorder, 15% met criteria for 1, 9% for 2, and 8% for ≥3 psychiatric disorders. Participants with ≥2 psychiatric disorders were more likely to have repeated a grade, to have an individualized educational program, and to have a lower nonverbal IQ than those with no psychiatric disorders. Participants with any psychiatric disorder were more likely to use psychotropic medications; to have greater cognitive and functional impairment; and to have mothers who were single, were on public health insurance, and had less than a high school education. Finally, a positive family psychiatric history was identified more frequently among adolescents with ≥3 psychiatric disorders.

CONCLUSION

Among adolescents born extremely preterm, anxiety, major depression, and attention-deficit/hyperactivity disorder were the most prevalent psychiatric disorders at age 15. Adolescents with >1 psychiatric disorder were at increased risk for multiple functional and participatory challenges.

Neurodevelopmental profiles of infants born <30 weeks gestation at 2 years of age

BACKGROUND

Infants born <30 weeks postmenstrual age (PMA) are at increased risk for neurodevelopmental impairment by age 2. Prior studies report rates of impairment for individual outcomes separately. Our objective was to describe neurodevelopmental profiles of children born <30 weeks PMA, using cognitive, language, motor, and behavioral characteristics.

METHODS

We studied 587 children from a multi-center study of infants born <30 weeks PMA. Age 2 outcomes included Bayley-III subscale scores, Child Behavior Checklist syndrome scores, diagnosis of cerebral palsy (CP), and positive screen for autism spectrum disorder (ASD) risk. We used latent profile analysis (LPA) to group children into mutually exclusive profiles.

RESULTS

We found four discrete neurodevelopmental profiles indicating distinct combinations of developmental and behavioral outcomes. Two of the profiles included 72.7% of the sample with most having Bayley scores within the normal range. The other two profiles included the remaining 27.3% of the sample with most having Bayley scores outside of the normal range. Only one profile (11% of sample) was comprised of children with elevated behavioral problems.

CONCLUSION

Child-centered analysis techniques could facilitate the development of targeted intervention strategies and provide caregivers and practitioners with an integrative understanding of child behavior.

IMPACT

Most studies examining neurodevelopmental outcomes in very preterm children report rates of impairment for individual outcomes separately. Comprehensive, "child-centered" approaches that integrate across multiple domains can be used to identify subgroups of children who experience different types of neurodevelopmental impairments. We identified four discrete neurodevelopmental profiles indicating distinct combinations of developmental and behavioral outcomes in very preterm children at 24 months. "Child-centered" analysis techniques may provide clinically useful information and could facilitate the development of targeted intervention strategies for high-risk children.

Associations between maternal pre-pregnancy body mass index and neonatal neurobehavior in infants born before 30 weeks gestation

OBJECTIVE

To examine the relationship between maternal pre-pregnancy body mass index (BMI) and neonatal neurobehavior in very premature infants.

STUDY DESIGN

Multi-center prospective observational study of 664 very preterm infants with 227 born to obese mothers. The NICU Network Neurobehavioral Scale (NNNS) assessed neurobehavior at NICU discharge.

RESULTS

Elevated BMI combined with infection increased the odds of having the most poorly regulated NNNS profile by 1.9 times per BMI SD. Infants born to mothers with elevated BMI in combination with: infection had poorer self-regulation, chorioamnionitis had increased asymmetrical reflexes, diabetes had poorer attention, and low SES required more handling.

CONCLUSION

Maternal pre-pregnancy BMI alone did not affect short-term neonatal neurobehavior in infants born before 30 weeks gestation. Infants born to mothers with elevated pre-pregnancy weight in addition to infections, diabetes, or socioeconomic adversity demonstrated increased risk of having the most poorly regulated NNNS profile and deficits in multiple domains.

Extreme prematurity: Risk and resiliency

Individuals born extremely preterm (before 28 weeks of gestation) comprise only about 0.7% of births in the United States and an even lower proportion in other high resource countries. However, these individuals account for a disproportionate number of children with cerebral palsy, intellectual deficit, autism spectrum disorder, attention deficit hyperactivity disorder, and epilepsy. This review describes two large multiple center cohorts comprised of individuals born extremely preterm: the EPICURE cohort, recruited 1995 in the United Kingdom and the Republic of Ireland, and the Extremely Low Gestational Age Newborn (ELGAN), recruited 2002-2004 in five states in the United States. The primary focus of these studies has been neurodevelopmental disorders, but also of interest are growth, respiratory illness, and parent- and self-reported global health and well-being. Both of these studies indicate that among individuals born extremely preterm the risks of most neurodevelopmental disorders are increased. Early life factors that contribute to this risk include perinatal brain damage, some of which can be identified using neonatal head ultrasound, bronchopulmonary dysplasia, and neonatal systemic inflammation. Prenatal factors, particularly the family's socioeconomic position, also appear to contribute to risk. For most adverse outcomes, the risk is higher in males. Young adults born extremely preterm who have neurodevelopmental impairment, as compared to those without such impairment, rate their quality of life lower. However, young adults born extremely preterm who do not have neurodevelopmental impairments rate their quality of life as being similar to that of young adults born at term. Finally, we summarize the current state of interventions designed to improve the life course of extremely premature infants, with particular focus on efforts to prevent premature birth and on postnatal efforts to prevent adverse neurodevelopmental outcomes.

White matter injury in the neonatal hypoxic-ischemic brain and potential therapies targeting microglia

Neonatal hypoxic-ischemic (H-I) injury, which mainly causes neuronal damage and white matter injury (WMI), is among the predominant causes of infant morbidity (cerebral palsy, cognitive and persistent motor disabilities) and mortality. Disruptions to the oxygen and blood supply in the perinatal brain affect the cerebral microenvironment and may affect microglial activation, excitotoxicity, and oxidative stress. Microglia are significantly associated with axonal damage and myelinating oligodendrocytes, which are major pathological components of WMI. However, the effects of H-I injury on microglial functions and underlying transformation mechanisms remain poorly understood. The historical perception that these cells are major risk factors for ischemic stroke has been questioned due to our improved understanding of the diversity of microglial phenotypes and their alterable functions, which exacerbate or attenuate injuries in different regions in response to environmental instability. Unfortunately, although therapeutic hypothermia is an efficient treatment, death and disability remain the prognosis for a large proportion of neonates with H-I injury. Hence, novel neuroprotective therapies to treat WMI following H-I injury are urgently needed. Here, we review microglial mechanisms that might occur in the developing brain due to neonatal H-I injury and discuss whether microglia function as a double-edged sword in WMI. Then, we emphasize microglial heterogeneity, notably at the single-cell level, and sex-specific effects on the etiology of neurological diseases. Finally, we discuss current knowledge of strategies aiming to improve microglia modulation and remyelination following neonatal H-I injury. Overall, microglia-targeted therapy might provide novel and valuable insights into the treatment of neonatal H-I insult.

Placental programming, perinatal inflammation, and neurodevelopment impairment among those born extremely preterm

Individuals born extremely preterm are at significant risk for impaired neurodevelopment. After discharge from the neonatal intensive care, associations between the child's well-being and factors in the home and social environment become increasingly apparent. Mothers' prenatal health and socioeconomic status are associated with neurodevelopmental outcomes, and emotional and behavioral problems. Research on early life risk factors and on mechanisms underlying inter-individual differences in neurodevelopment later in life can inform the design of personalized approaches to prevention. Here, we review early life predictors of inter-individual differences in later life neurodevelopment among those born extremely preterm. Among biological mechanisms that mediate relationships between early life predictors and later neurodevelopmental outcomes, we highlight evidence for disrupted placental processes and regulated at least in part via epigenetic mechanisms, as well as perinatal inflammation. In relation to these mechanisms, we focus on four prenatal antecedents of impaired neurodevelopment, namely, (1) fetal growth restriction, (2) maternal obesity, (3) placental microorganisms, and (4) socioeconomic adversity. In the future, this knowledge may inform efforts to detect and prevent adverse outcomes in infants born extremely preterm. IMPACT: This review highlights early life risk factors and mechanisms underlying inter-individual differences in neurodevelopment later in life. The review emphasizes research on early life risk factors (fetal growth restriction, maternal obesity, placental microorganisms, and socioeconomic adversity) and on mechanisms (disrupted placental processes and perinatal inflammation) underlying inter-individual differences in neurodevelopment later in life. The findings highlighted here may inform efforts to detect and prevent adverse outcomes in infants born extremely preterm.

Neurodevelopment at 2 years corrected age among Vietnamese preterm infants

BACKGROUND

Preterm infants are at risk of neurodevelopmental delay, but data on long-term outcomes in low-income and middle-income countries remain scarce.

OBJECTIVES

To examine neurodevelopment using Bayley Scales of Infant and Toddler Development-3rd edition (Bayley-III) and neurological findings in 2-year-old preterm infants, and to compare with healthy Vietnamese infants. Further, to assess factors associated with neurodevelopmental impairment.

DESIGN AND SETTING

Cohort study to follow up preterm infants discharged from a neonatal intensive care unit (NICU) of a tertiary children's hospital in Vietnam.

PARTICIPANTS

Infants born at <37 weeks of gestational age.

MAIN OUTCOMES

Bayley-III assessment and neurological examination at 2-year corrected age (CA) compared with healthy Vietnamese infants.

RESULTS

Of 294 NICU preterm infants, Bayley-III scores of all 184/243 (76%) survivors at 2 years CA were significantly lower than those of healthy Vietnamese peers in all three domains: cognition (mean (SD): 84.5 (8.6) vs 91.4 (7.5), p<0.001), language (mean (SD): 88.7 (12.5) vs 95.9 (11.9), p<0.001) and motor (mean (SD): 93.1 (9.0) vs 96.8 (9.3), p=0.003). The mean differences in Bayley-III scores between preterm and healthy Vietnamese infants were -6.9 (-9.1 to -4.7), -7.2 (-10.5 to -3.8) and -3.7 (-6.1 to -1.2) for cognitive, language and motor scores, respectively. The prevalence of neurodevelopmental impairment was 17% for cognitive, 8% for language and 4% for motor performance. In total, 7% were diagnosed with cerebral palsy. Higher maternal education was positively associated with infant neurodevelopment (OR 0.32, 95% CI 0.11 to 0.94).

CONCLUSIONS

Vietnamese preterm infants in need of neonatal intensive care showed poor neurodevelopment at 2 years. Higher maternal education was positively associated with infant neurodevelopment. Standard follow-up programmes for preterm infants should be considered in low-resource settings.

Neurocognitive and social-communicative function of children born very preterm at 10 years of age: Associations with microorganisms recovered from the placenta parenchyma

OBJECTIVE

Infection of the placenta has been associated with preterm birth as well as neurocognitive impairment. This study aimed to determine whether specific bacterial species in the placenta of extremely preterm pregnancies are associated with neurological deficits later in life.

STUDY DESIGN

Using data from 807 children in the ELGAN study the risks of a low score on six neurological assessments in relation to 15 different microbes were quantified with odds ratios.

RESULTS

The presence of certain microbial species in the placenta was associated with lower scores on numerical and oral language assessments. Lactobacillus sp. was associated with decreased risk of a low oral language score and a composite measure of IQ and executive function.

CONCLUSION

Placental microorganisms were associated with neurocognitive, but not social-communicative, outcomes at age 10. In contrast, the presence of the anti-inflammatory Lactobacillus sp. in the placenta was associated with a lower risk of impaired neurocognitive functions.

Why considering sexual differences is necessary when studying encephalopathy of prematurity through rodent models

Preterm birth is a high-risk factor for the development of gray and white matter abnormalities, referred to as "encephalopathy of prematurity," that may lead to life-long motor, cognitive, and behavioral impairments. The prevalence and clinical outcomes of encephalopathy of prematurity differ between sexes, and elucidating the underlying biological basis has become a high-priority challenge. Human studies are often limited to assessment of brain region volumes by MRI, which does not provide much information about the underlying mechanisms of lesions related to very preterm birth. However, models using KO mice or pharmacological manipulations in rodents allow relevant observations to help clarify the mechanisms of injury sustaining sex-differential vulnerability. This review focuses on data obtained from mice aged P1-P5 or rats aged P3 when submitted to cerebral damage such as hypoxia-ischemia, as their brain lesions share similarities with lesion patterns occurring in very preterm human brain, before 32 gestational weeks. We first report data on the mechanisms underlying the development of sexual brain dimorphism in rodent, focusing on the hippocampus. In the second part, we describe sex specificities of rodent models of encephalopathy of prematurity (RMEP), focusing on mechanisms underlying differences in hippocampal vulnerability. Finally, we discuss the relevance of these RMEP. Together, this review highlights the need to systematically search for potential effects of sex when studying the mechanisms underlying deficits in RMEP in order to design effective sex-specific medical interventions in human preterms.

Psychiatric Symptoms: Prevalence, Co-occurrence, and Functioning Among Extremely Low Gestational Age Newborns at Age 10 Years

OBJECTIVE

To evaluate the percentage of children born extremely preterm (EP) who screen positive for ≥1 DSM-IV psychiatric disorders, the co-occurrence of and sex-related differences in these classifications, and the functional correlates of psychiatric symptoms.

METHODS

The Extremely Low Gestational Age Newborn (ELGAN) Study is a prospective cohort follow-up of children born <28 weeks' gestation. For 871 10-year-old children, parents completed the Child Symptom Inventory-4 (CSI-4), a child educational/medical history questionnaire, and the Pediatric Quality of Life Inventory (PedsQL).

RESULTS

At age 10 years, ELGANs were more likely to screen positive for a number of psychiatric disorders when compared with normative expectations on the CSI-4, with a few sex-related differences. Fifteen percent of participants screened positive for 1 disorder, 7% for 2, 3% for 3, and 4% for ≥4 psychiatric disorders. Compared with children who did not screen positive for psychiatric disorders, children who screened positive for ≥3 psychiatric disorders were approximately twice as likely to have repeated a grade, have an individualized educational program, have an individual school aide, and to require special remediation classes. Children who screened positive for any psychiatric disorder were 4 times more likely to use 1 or more psychotropic medication, and those who screened positive for ≥2 psychiatric disorders had lower PedsQL scores.

CONCLUSION

Among 10-year-old children born EP, rates of psychiatric symptoms exceeded normative expectation, and children who screened positive for more than 1 psychiatric disorder were at increased risk of having multiple functional impairments.

Does gender affect Bayley-III scores and test-taking behavior?

The developmental test Bayley-III is widely used in clinical and research settings, but there are no published gender-specific norms. The purpose of the present study was to investigate gender differences in Bayley-III scores in a sample of 55 typically developing children assessed repeatedly at ages 4, 7, 10, 13, 24 and 36 months, and to investigate gender differences in the test-taking behavior of the children as measured with the BRS at 36 months. The results of the study demonstrated gender differences at 24 and 36 months for the Cognitive Scale, at 10, 13, 24 and 36 months for the Language Scale and at 36 months for the Motor Scale. On a subtest level, gender differences were found for the Receptive Communication subtest at 13, 24 and 36 months and for the Fine Motor subtest at 7 and 36 months. In all cases where significant gender differences were found, girls achieved higher mean scores than boys. No gender differences were found in the children's test-taking behavior at 36 months on any of the BRS scales, but independently of gender, higher Bayley-III Cognitive and Motor Scale scores were associated with more compliant test-taking behavior.

Prenatal Risk Factors for Adverse Developmental Outcome in Preterm Infants-Systematic Review

Background: Preterm infants are still at an increased risk for suboptimal neurodevelopmental outcomes when compared with term born infants. The development of a child born preterm can be jeopardized by suboptimal conditions during pregnancy, in addition to the suboptimal growth environment postnatally compared to the normal in utero environment. This review summarizes the literature on the role of chorioamnionitis, placental insufficiency, and maternal smoking on the developmental outcomes of preterm infants. Methods: A systematic database search was performed to identify all original articles published on or before September 12, 2018 that evaluated the impact of clinical or histological chorioamnionitis, abnormal prenatal fetal and placental blood flow, and prenatal smoking exposure on the neuropsychological and cognitive outcomes of preterm infants. We identified a total of 54 studies. Thirty five original articles evaluated the effects of clinical or histological chorioamnionitis; 15 studies evaluated the effects of abnormal blood flow patterns; and four studies evaluated the effects of maternal smoking during pregnancy. Results: The studies on prenatal risk factors showed conflicting results about the impact on the neurodevelopment of preterm infants. The majority of the studies did not show that chorioamnionitis poses a direct risk to the development of preterm infants. The role of abnormal prenatal placental and fetal blood flow on the development of preterm infants remained inconclusive because the sample sizes were often small and methodological problems complicated the interpretation of the data. Maternal smoking during pregnancy was assessed only in one cohort which showed that maternal smoking is a risk for suboptimal cognitive and neuropsychological development in preterm infants. Conclusions: This review summarizes the data on several prenatal risk factors which play a role in the developmental outcomes of preterm infants. To optimize the developmental outcomes, we need to first optimize the fetal wellbeing before birth. More research that extends from the fetal life to long-term developmental outcomes is needed.

The long-term effects of childhood traumatic brain injury on adulthood relationship quality

PRIMARY OBJECTIVE

To investigated the long-term effect of childhood Traumatic Brain Injury (TBI) on adulthood Relationship Quality (RQ), examining injury severity, age of injury, and markers of prefrontal cortex (PFC) functioning, apathy, disinhibition, and executive dysfunction.

RESEARCH DESIGN

Longitudinal, between-subjects, cross-sectional design using retrospective and current data.

METHODS AND PROCEDURES

Participants (N = 169; 61 mild TBI (mTBI); 65 moderate to severe TBI (MSTBI); 43 orthopaedic injury (OI); Injury age: 1-17 years; Testing age: 18-31 years) completed a structured interview regarding their injury, demographic characteristics and RQ, the National Adults Reading Test, and Frontal Systems Behaviour Scale. Data were analyzed using IBM SPSS 25.

MAIN OUTCOMES AND RESULTS

Adults who had experienced childhood TBI had significantly poorer RQ than adults who had experienced childhood OI. Severity of TBI did not impact adulthood RQ. Earlier age of injury predicted reduced adulthood RQ in the MSTBI group. Greater PFC dysfunction predicted poorer RQ in adults with a history of childhood TBI. While elevated levels of apathy, disinhibition, and executive dysfunction were associated with poorer RQ, no individual marker had predictive value.

CONCLUSION

Experiencing a childhood TBI can have a long-term negative influence on adulthood RQ. Such RQ deficits can underpin reduced life satisfaction and increased health issues.

The placenta

Examination of the placenta provides a unique opportunity to explore and understand the intrauterine environment, as well as providing a record of events that may be associated with adverse pregnancy outcomes, one of the most devastating of which is central nervous system (CNS) injury. A number of placental lesions have been described in association with various forms of neurologic injury. They can be divided into four major categories: sentinel events, inflammatory lesions, vascular lesions, and "biomarker" lesions, which are not themselves causative, but are often found in association with other lesions that are causative. The purpose of this review is to outline these placental lesions and summarize the types of CNS injury that have been described in association with each. Finally, one of the most important of all risk factors for CNS injury is the finding of multiple independent placental lesions. The effects of these lesions may be synergistic, particularly when metachronous, with an earlier lesion leaving the CNS more vulnerable to the effects of a later lesion.

Accuracy of the Bayley-II mental development index at 2 years as a predictor of cognitive impairment at school age among children born extremely preterm

OBJECTIVE

To describe the accuracy of the Bayley Scales of Infant Development-Second Edition (BSID-II) Mental Development Index (MDI) at 2 years of age for prediction of cognitive function at school age of children born extremely preterm.

DESIGN

Study participants were enrolled in the Extremely Low Gestational Age Newborn Study between 2002 and 2004. Two-thirds of surviving children (n = 795) were assessed at 2 years with the BSID-II and at 10 years with an intelligence quotient (IQ) test. We computed test characteristics for a low MDI (<70), including predictive value positive.

RESULTS

Almost two-thirds of children with a low MDI had a normal IQ (≥ 70) at 10 years. Concordance between MDI and IQ was highest among children with major motor and/or sensory impairment, and when MDI was adjusted for gestational age.

CONCLUSION

Most children born extremely preterm with low BSID-II MDI at 2 years have normal intelligence at school age.

Cognitive Development and Quality of Life Associated With BPD in 10-Year-Olds Born Preterm

OBJECTIVES

To compare neurocognitive, language, executive function, academic achievement, neurologic and behavioral outcomes, and quality of life at age 10 years in children born extremely preterm who developed bronchopulmonary dysplasia (BPD) to children who did not develop BPD.

METHODS

The Extremely Low Gestational Age Newborns study population included 863 children born extremely preterm whose BPD status before discharge was known had an IQ (Differential Ability Scales II [DAS II]) assessment at 10 years. We evaluated the association of BPD with any cognitive (DAS II), executive function (NEuroPSYchological Assessment II), academic achievement (Wechsler Individual Achievement Test-III and Oral and Written Language Scales [OWLS]) as well as social dysfunctions (Social Responsiveness Scale). We used logistic regression models, adjusting for potential confounding factors, to assess the strength of association between the severity of BPD and each outcomes.

RESULTS

Three hundred and seventy-two (43%) children were oxygen-dependent at 36 weeks postconception age, whereas an additional 78 (9%) were also oxygen- and ventilator-dependent. IQ scores 2 or more SDs below the expected mean (ie, z scores ≤-2) occurred twice as commonly among children who had BPD as among those who did not. Children with severe BPD consistently had the lowest scores on DAS II, OWLS, Wechsler Individual Achievement Test-III, NEuroPSYchological Assessment II, and Social Responsiveness Scale assessments.

CONCLUSIONS

Among 10-year-old children born extremely preterm, those who had BPD were at increased risk of cognitive, language, and executive dysfunctions; academic achievement limitations; social skill deficits; and low scores on assessments of health-related quality of life.

Maternal body mass index and risk of intraventricular hemorrhage in preterm infants

BackgroundIntraventricular hemorrhage (IVH) and pre-pregnancy obesity and underweight have been linked to inflammatory states. We hypothesize that IVH in preterm infants is associated with pre-pregnancy obesity and underweight due to an inflammatory intrauterine environment.MethodsPopulation-based study of infants born between 22 and 32 weeks' gestation from 2007 to 2011. Data were extracted from vital statistics and the California Perinatal Quality Care Collaborative. Results were examined for all cases (any IVH) and for severe IVH.ResultsAmong 20,927 infants, 4,818 (23%) had any IVH and 1,514 (7%) had severe IVH. After adjustment for confounders, there was an increased risk of IVH associated with pre-pregnancy obesity, relative risk 1.14 (95% confidence interval (CI) 1.06, 1.32) for any IVH, and 1.25 (85% CI 1.10, 1.42) for severe IVH. The direct effect of pre-pregnancy obesity on any IVH was significant (P<0.001) after controlling for antenatal inflammation-related conditions, but was not significant after controlling for gestational age (P=0.56).ConclusionPre-pregnancy obesity was found to be a risk factor for IVH in preterm infants; however, this relationship appeared to be largely mediated through the effect of BMI on gestational age at delivery. The etiology of IVH is complex and it is important to understand the contributing maternal factors.

Maternal pre-pregnancy obesity and child neurodevelopmental outcomes: a meta-analysis

This review examined evidence of the association between maternal pre-pregnancy overweight/obesity status and child neurodevelopmental outcomes. PubMed and PsycINFO databases were systematically searched for empirical studies published before April 2017 using keywords related to prenatal obesity and children's neurodevelopment. Of 1483 identified papers, 41 were included in the systematic review, and 32 articles representing 36 cohorts were included in the meta-analysis. Findings indicated that compared with children of normal weight mothers, children whose mothers were overweight or obese prior to pregnancy were at increased risk for compromised neurodevelopmental outcomes (overweight: OR = 1.17, 95% CI [1.11, 1.24], I²  = 65.51; obese: OR = 1.51; 95% CI [1.35, 1.69], I²  = 79.63). Pre-pregnancy obesity increased the risk of attention deficit-hyperactivity disorder (OR = 1.62; 95% CI [1.23, 2.14], I²  = 70.15), autism spectrum disorder (OR = 1.36; 95% CI [1.08, 1.70], I²  = 60.52), developmental delay (OR = 1.58; 95% CI [1.39, 1.79], I²  = 75.77) and emotional/behavioural problems (OR = 1.42; 95% CI [1.26, 1.59], I²  = 87.74). Given the current obesity prevalence among young adults and women of childbearing age, this association between maternal obesity during pregnancy and atypical child neurodevelopment represents a potentially high public health burden.

Hand Preference and Cognitive, Motor, and Behavioral Functioning in 10-Year-Old Extremely Preterm Children

The association of hand preference (left, mixed, and right) with cognitive, academic, motor, and behavioral function was evaluated in 864 extremely preterm children at 10 years of age. Left-handed and right-handed children performed similarly but mixed-handed children had greater odds of functional deficits across domains than right-handed children.

Antenatal and Neonatal Antecedents of Executive Dysfunctions in Extremely Preterm Children

To find out why children born extremely preterm are at heightened risk of executive dysfunctions, the authors assessed 716 children who were 10 years old born extremely preterm whose IQ was ≥ 70. A working memory dysfunction (n = 169), an inhibition dysfunction (n = 360), a switching dysfunction (355), and all 3 (executive dysfunction; n = 107) were defined on the basis of Z-scores ≤ -1 on the Differential Ability Scales-II Working Memory composite, and/or on the NEPSY-II Inhibition-Inhibition and Inhibition-Switching subtests. All risk profiles include an indicator of socioeconomic disadvantage. The risk profile of each of the 3 individual dysfunctions includes an indicator of the newborn's immaturity, and the risk profiles of the inhibition dysfunction and switching dysfunction also include an indicator of inflammation. Only the switching dysfunction was associated with fetal growth restriction. The risk factors for executive dysfunction can be subsumed under the 4 themes of socioeconomic disadvantage, immaturity/vulnerability, inflammation, and fetal growth restriction.

Antenatal and neonatal antecedents of learning limitations in 10-year old children born extremely preterm

BACKGROUND

Children born extremely preterm are at increased risk of learning limitations.

AIM

To identify the antecedents of learning limitations of children born extremely preterm.

STUDY DESIGN

Prospective observational study from birth to age 10 years. Variables entered into the multinomial logistic regression analyses were ordered temporally, with the earliest occurring predictors/covariates of each learning limitation risk entered first and not displaced by later occurring covariates.

SUBJECTS

874 children who were born before the 28th week of gestation.

OUTCOME MEASURES

A reading limitation was defined as a score one or more standard deviations below the expected mean on the WIAT-III Word Reading and a mathematics limitation was defined as a similarly low score on the Numerical Operations component.

RESULTS

56 children had a "reading ONLY" limitation, 132 children had a "math ONLY" limitation and 89 children had "reading AND math" limitations. All risk profiles included an indicator of socioeconomic disadvantage (e.g., mother's "racial" identity and eligibility for government-provided health care insurance), an indicator of newborn's immaturity/vulnerability (e.g., high illness severity score, receipt of hydrocortisone, and/or ventilator-dependence at 36 weeks post-menstruation), and all but the math only limitation included an indicator of fetal growth restriction and inflammation (i.e., pregnancy urinary tract infection or late ventilator-dependence).

CONCLUSIONS

The themes of socioeconomic disadvantage and immaturity/vulnerability characterize all three risk profiles, while the themes of fetal growth restriction and inflammation are characteristic of a reading limitation only, and the reading and math limitations entity.

Placental Findings and Effect of Prophylactic Hydrocortisone in Extremely Preterm Infants

OBJECTIVES

To investigate the relationship between histologic findings of the placenta and response to early postnatal hydrocortisone treatment used to prevent bronchopulmonary dysplasia (BPD) in extremely preterm infants.

METHODS

In an exploratory analysis of the Early Low-Dose Hydrocortisone to Improve Survival Without Bronchopulmonary Dysplasia in Extremely Preterm Infants (PREMILOC) trial, detailed placental analyses were performed on the basis of standardized macroscopic and histologic examinations. Placental histology, categorized into 3 groups, was correlated to neonatal outcomes and response to hydrocortisone treatment.

RESULTS

Of 523 randomly assigned patients, 457 placentas were analyzed. In total, 125 out of 457 (27%) placentas were classified as normal, 236 out of 457 (52%) placentas were classified as inflammatory, and 96 out of 457 (21%) placentas were classified as vascular. Placental inflammation was associated with a significant, increased rate of BPD-free survival at 36 weeks' postmenstrual age, independent of gestational age, treatment group, and sex (adjusted odds ratio: 1.72, 95% confidence interval [CI]: 1.05 to 2.82, P = .03). Regarding the response to treatment, the strongest benefit of hydrocortisone compared with placebo was found in infants born after placental vascular disease, with significantly more patients extubated at day 10 (risk difference: 0.32, 95% CI: 0.08 to 0.56, P = .004) and similar positive direction on survival without BPD (risk difference: 0.23, 95% CI: 0.00 to 0.46, P = .06). Adjusted to gestational age and treatment groups, placental inflammation was associated with significantly fewer patent ductus arteriosus ligation (adjusted hazard ratio: 0.58, 95% CI: 0.36 to 0.95, P = .03). Placental histology was not found to be associated with other adverse events related to preterm birth.

CONCLUSIONS

With these findings, we confirm that early low-dose hydrocortisone confers benefits in extremely preterm infants overall and we suggest there is a higher treatment effect in those born after placental vascular disease.

Complex interactions between hypoxia-ischemia and inflammation in preterm brain injury

Children surviving preterm birth have a high risk of disability, particularly cognitive and learning problems. There is extensive clinical and experimental evidence that disability is now primarily related to dysmaturation of white and gray matter, defined by failure of oligodendrocyte maturation and neuronal dendritic arborization, rather than cell death alone. The etiology of this dysmaturation is multifactorial, with contributions from hypoxia-ischemia, infection/inflammation and barotrauma. Intriguingly, these factors can interact to both increase and decrease damage. In this review we summarize preclinical and clinical evidence that all of these factors trigger secondary or chronic inflammation and gliosis. Thus, we hypothesize that these shared pathological features play a key role in a final common pathway that leads to the impaired neural maturation and connectivity and cognitive/motor impairments that are commonly observed in infants born preterm. This raises the possibility that secondary or chronic inflammation may be a viable therapeutic target for delayed interventions to improve neurodevelopmental outcomes after preterm birth.

WHAT THIS PAPER ADDS

Hypoxia-ischemia, infection/inflammation, and barotrauma/volutrauma all contribute to preterm brain injury. Multiple different triggers of preterm brain injury are associated with central nervous system dysmaturation. Secondary brain inflammation may be a viable target to improve neurodevelopment after preterm birth.

Glia and hemichannels: key mediators of perinatal encephalopathy

Perinatal encephalopathy remains a major cause of disability, such as cerebral palsy. Therapeutic hypothermia is now well established to partially reduce risk of disability in late preterm/term infants. However, new and complementary therapeutic targets are needed to further improve outcomes. There is increasing evidence that glia play a key role in neural damage after hypoxia-ischemia and infection/inflammation. In this review, we discuss the role of astrocytic gap junction (connexin) hemichannels in the spread of neural injury after hypoxia-ischemia and/or infection/inflammation. Potential mechanisms of hemichannel mediated injury likely involve impaired intracellular calcium handling, loss of blood-brain barrier integrity and release of adenosine triphosphate (ATP) resulting in over-activation of purinergic receptors. We propose the hypothesis that inflammation-induced opening of connexin hemichannels is a key regulating event that initiates a vicious cycle of excessive ATP release, which in turn propagates activation of purinergic receptors on microglia and astrocytes. This suggests that developing new neuroprotective strategies for preterm infants will benefit from a detailed understanding of glial and connexin hemichannel responses.

Neurodevelopment at Age 10 Years of Children Born <28 Weeks With Fetal Growth Restriction

OBJECTIVES

We sought to evaluate the relationships between fetal growth restriction (FGR) (both severe and less severe) and assessments of cognitive, academic, and adaptive behavior brain function at age 10 years.

METHODS

At age 10 years, the Extremely Low Gestational Age Newborns Cohort Study assessed the cognitive function, academic achievement, social-communicative function, psychiatric symptoms, and overall quality of life of 889 children born before 28 weeks' gestation. A pediatric epileptologist also interviewed parents as part of a seizure evaluation. The 52 children whose birth weight z scores were <-2 were classified as having severe FGR, and the 113 whose birth weight z scores were between -2 and -1 were considered to have less severe FGR.

RESULTS

The more severe the growth restriction in utero, the lower the level of function on multiple cognitive and academic achievement assessments performed at age 10 years. Growth-restricted children were also more likely than their extremely preterm peers to have social awareness impairments, autistic mannerisms, autism spectrum diagnoses, difficulty with semantics and speech coherence, and diminished social and psychosocial functioning. They also more frequently had phobias, obsessions, and compulsions (according to teacher, but not parent, report).

CONCLUSIONS

Among children born extremely preterm, those with severe FGR appear to be at increased risk of multiple cognitive and behavioral dysfunctions at age 10 years, raising the possibility that whatever adversely affected their intrauterine growth also adversely affected multiple domains of cognitive and neurobehavioral development.

The Relationship of Maternal Prepregnancy Body Mass Index and Pregnancy Weight Gain to Neurocognitive Function at Age 10 Years among Children Born Extremely Preterm

OBJECTIVE

To assess the association between maternal prepregnancy body mass index and adequacy of pregnancy weight gain in relation to neurocognitive function in school-aged children born extremely preterm.

STUDY DESIGN

Study participants were 535 ten-year-old children enrolled previously in the prospective multicenter Extremely Low Gestational Age Newborns cohort study who were products of singleton pregnancies. Soon after delivery, mothers provided information about prepregnancy weight. Prepregnancy body mass index and adequacy of weight gain were characterized based on this information. Children underwent a neurocognitive evaluation at 10 years of age.

RESULTS

Maternal prepregnancy obesity was associated with increased odds of a lower score for Differential Ability Scales-II Verbal IQ, for Developmental Neuropsychological Assessment-II measures of processing speed and visual fine motor control, and for Wechsler Individual Achievement Test-III Spelling. Children born to mothers who gained an excessive amount of weight were at increased odds of a low score on the Oral and Written Language Scales Oral Expression assessment. Conversely, children whose mother did not gain an adequate amount of weight were at increased odds of a lower score on the Oral and Written Language Scales Oral Expression and Wechsler Individual Achievement Test-III Word Reading assessments.

CONCLUSION

In this cohort of infants born extremely preterm, maternal obesity was associated with poorer performance on some assessments of neurocognitive function. Our findings are consistent with the observational and experimental literature and suggest that opportunities may exist to mitigate risk through education and behavioral intervention before pregnancy.

Genomic biomarkers of prenatal intrauterine inflammation in umbilical cord tissue predict later life neurological outcomes

BACKGROUND

Preterm birth is a major risk factor for neurodevelopmental delays and disorders. This study aimed to identify genomic biomarkers of intrauterine inflammation in umbilical cord tissue in preterm neonates that predict cognitive impairment at 10 years of age.

STUDY DESIGN

Genome-wide messenger RNA (mRNA) levels from umbilical cord tissue were obtained from 43 neonates born before 28 weeks of gestation. Genes that were differentially expressed across four indicators of intrauterine inflammation were identified and their functions examined. Exact logistic regression was used to test whether expression levels in umbilical cord tissue predicted neurocognitive function at 10 years of age.

RESULTS

Placental indicators of inflammation were associated with changes in the mRNA expression of 445 genes in umbilical cord tissue. Transcripts with decreased expression showed significant enrichment for biological signaling processes related to neuronal development and growth. The altered expression of six genes was found to predict neurocognitive impairment when children were 10 years old These genes include two that encode for proteins involved in neuronal development.

CONCLUSION

Prenatal intrauterine inflammation is associated with altered gene expression in umbilical cord tissue. A set of six of the differentially expressed genes predict cognitive impairment later in life, suggesting that the fetal environment is associated with significant adverse effects on neurodevelopment that persist into later childhood.

Neurocognitive Correlates of Attention-Deficit Hyperactivity Disorder Symptoms in Children Born at Extremely Low Gestational Age

OBJECTIVE

Compared with children born near term, those born extremely preterm (EP) are at much higher risk for attention-deficit hyperactivity disorder (ADHD). Little information is available about differences in neuropsychological outcomes among EP children with and without ADHD. Our analyses aimed to evaluate the neuropsychological correlates of ADHD symptoms in extremely low gestational age newborns (ELGANs).

METHODS

We obtained Child Symptom Inventory-4 reports from parents (n = 871) and teachers (n = 634) of 10-year-old children born before the 28th week of gestation. Participants completed standardized assessments of neurocognitive and academic functioning.

RESULTS

In the total sample, children who screened positive for ADHD symptoms were at increased risk for neurocognitive limitations. These associations were weaker when the sample was limited to those with intelligence quotient (IQ) ≥70 or ≥85. Even those with IQ ≥85 who screened positive for ADHD symptoms were more likely than their peers to have deficits on the DAS-II Working Memory Cluster and the NEPSY-II Auditory Response subtest. The risks for impaired academic performance (Z ≤ -1) on components of the WIAT-III were 2-to-3 times higher in this group than among ELGANs not classified as having ADHD symptoms.

CONCLUSION

Among children born EP, those with ADHD symptoms are more likely to have global neurocognitive impairment. When IQ is within normal limits, ADHD symptoms are associated with deficits in executive functioning skills. These findings highlight a group at risk for executive functioning deficits and related academic difficulties, even in the absence of intellectual disability.

Risk Factor Models for Neurodevelopmental Outcomes in Children Born Very Preterm or With Very Low Birth Weight: A Systematic Review of Methodology and Reporting

The prediction of long-term outcomes in surviving infants born very preterm (VPT) or with very low birth weight (VLBW) is necessary to guide clinical management, provide information to parents, and help target and evaluate interventions. There is a large body of literature describing risk factor models for neurodevelopmental outcomes in VPT/VLBW children, yet few, if any, have been developed for use in routine clinical practice or adopted for use in research studies or policy evaluation. We sought to systematically review the methods and reporting of studies that have developed a multivariable risk factor model for neurodevelopment in surviving VPT/VLBW children. We searched the MEDLINE, Embase, and PsycINFO databases from January 1, 1990, to June 1, 2014, and identified 78 studies reporting 222 risk factor models. Most studies presented risk factor analyses that were not intended to be used for prediction, confirming that there is a dearth of specifically designed prognostic modeling studies for long-term outcomes in surviving VPT/VLBW children. We highlight the strengths and weaknesses of the research methodology and reporting to date, and provide recommendations for the design and analysis of future studies seeking to analyze risk prediction or develop prognostic models for VPT/VLBW children.

The role of systemic inflammation linking maternal BMI to neurodevelopment in children

Children of obese mothers are at increased risk of developmental adversities. Maternal obesity is linked to an inflammatory in utero environment, which, in turn, is associated with neurodevelopmental impairments in the offspring. This is an integrated mechanism review of animal and human literature related to the hypothesis that maternal obesity causes maternal and fetal inflammation, and that this inflammation adversely affects the neurodevelopment of children. We propose integrative models in which several aspects of inflammation are considered along the causative pathway linking maternal obesity with neurodevelopmental limitations.

Evaluation of the relationship between opioid exposure in extremely low birth weight infants in the neonatal intensive care unit and neurodevelopmental outcome at 2 years

BACKGROUND

Extremely low birth weight (ELBW) infants are exposed to many painful procedures while in the neonatal intensive care unit (NICU), such as catheter insertion and endotracheal intubation. Exposure of ELBW infants to repetitive pain and stress in the NICU can lead to cardiovascular instability and may alter neuronal and synaptic organization. Opioid analgesics are administered to reduce pain, stress and to potentially reduce poor neurologic outcomes. They may also be utilized as sedation for mechanically ventilated ELBW infants. There is limited data in regards to neurodevelopmental outcomes of preterm infants exposed to opioids, and available studies have conflicting results.

OBJECTIVE

To examine the relationship between cumulative opioid dose in ELBW infants in the NICU and neurodevelopmental outcomes at 20 months corrected age (CA).

STUDY DESIGN

100 ELBW infants who had complete neurodevelopmental assessments at 20 months CA were categorized by cumulative opioid exposure during the NICU stay (high vs. low/no opioid). Outcome measures included cognitive, motor and language scores from the Bayley Scales of Infant and Toddler Development-III (BSITD-III). Multiple regression analyses adjusted for the impact of social and neonatal risk factors on outcome.

RESULTS

There were 60 patients with high and 40 with low/no opioid exposure. Infants in the high dose group had a higher number of median ventilator days (53.5 vs. 45.6 days, p=0.046) and a higher incidence of necrotizing enterocolitis (5% vs. 21.7%, p=0.022). There were no significant differences in BSITD-III scores between the two opiate groups. In multivariate analysis cumulative opioid dose was associated with lower cognitive scores on the BSITD-III even after adjusting for social and neonatal risk factors (β=-0.247, p=0.012).

CONCLUSION

Cumulative opioid dose is associated with worse cognitive scores at 20 months CA even after adjusting for social and neonatal risk factors.

Genes and environment in neonatal intraventricular hemorrhage

Emerging data suggest intraventricular hemorrhage (IVH) of the preterm neonate is a complex disorder with contributions from both the environment and the genome. Environmental analyses suggest factors mediating both cerebral blood flow and angiogenesis contribute to IVH, while candidate gene studies report variants in angiogenesis, inflammation, and vascular pathways. Gene-by-environment interactions demonstrate the interaction between the environment and the genome, and a non-replicated genome-wide association study suggests that both environmental and genetic factors contribute to the risk for severe IVH in very low-birth weight preterm neonates.

Prognostic Factors for Poor Cognitive Development in Children Born Very Preterm or With Very Low Birth Weight: A Systematic Review

IMPORTANCE

Cognitive delay is the most common form of impairment among children born very preterm (VPT) at 32 weeks or less or with very low birth weight (VLBW) of 1250 g or less. It is important to identify factors that are robust predictors of long-term outcome because the ability to predict future prognosis will assist in health care and educational service planning and provision.

OBJECTIVE

To identify prognostic factors for poor cognitive development in children born VPT or with VLBW.

EVIDENCE REVIEW

A systematic review was conducted using MEDLINE, EMBASE, and PyscINFO databases to identify studies published between January 1, 1990, and June 1, 2014, reporting multivariable prediction models for neurodevelopment in VPT or VLBW children. Thirty-one studies comprising 98 risk factor models for cognitive outcome were identified. Two independent reviewers extracted key information on study design, outcome definition, risk factor selection, model development, and reporting and conducted a risk-of-bias assessment.

FINDINGS

There was evidence that male sex, nonwhite race/ethnicity, lower level of parental education, and lower birth weight were predictive of global cognitive impairment in children younger than 5 years. In older children, only the influence of parental education was sustained. Male sex was also predictive of language impairment in early infancy, but not in middle childhood. Gestational age was a poor predictor of cognitive outcome, probably because of a reduced discriminatory power in cohorts restricted to a narrow gestational age range. The prognostic value of neonatal brain injury was unclear; however, studies adopted mixed strategies for managing children with physical or neurosensory disability.

CONCLUSIONS AND RELEVANCE

The influence of perinatal risk factors on cognitive development of VPT or VLBW children appears to diminish over time as environmental factors become more important. It is difficult to isolate cognitive outcomes from motor and neurosensory impairment, and the strategy for dealing with untestable children has implications for risk prediction.

Role of the fetoplacental endothelium in fetal growth restriction with abnormal umbilical artery Doppler velocimetry

Growth-restricted fetuses with absent or reversed end-diastolic velocities in the umbilical artery are at substantially increased risk for adverse perinatal and long-term outcome, even in comparison to growth-restricted fetuses with preserved end-diastolic velocities. Translational studies show that this Doppler velocimetry correlates with fetoplacental blood flow, with absent or reversed end-diastolic velocities signifying abnormally elevated resistance within the placental vasculature. The fetoplacental vasculature is unique in that it is not subject to autonomic regulation, unlike other vascular beds. Instead, humoral mediators, many of which are synthesized by local endothelial cells, regulate placental vascular resistance. Existing data demonstrate that in growth-restricted pregnancies complicated by absent or reversed umbilical artery end-diastolic velocities, an imbalance in production of these vasoactive substances occurs, favoring vasoconstriction. Morphologically, placentas from these pregnancies also demonstrate impaired angiogenesis, whereby vessels within the terminal villi are sparsely branched, abnormally thin, and elongated. This structural deviation from normal placental angiogenesis restricts blood flow and further contributes to elevated fetoplacental vascular resistance. Although considerable work has been done in the field of fetoplacental vascular development and function, much remains unknown about the mechanisms underlying impaired development and function of the human fetoplacental vasculature, especially in the context of severe fetal growth restriction with absent or reversed umbilical artery end-diastolic velocities. Fetoplacental endothelial cells are key regulators of angiogenesis and vasomotor tone. A thorough understanding of their role in placental vascular biology carries the significant potential of discovering clinically relevant and innovative approaches to prevention and treatment of fetal growth restriction with compromised umbilical artery end-diastolic velocities.

Maternal obesity and development of the preterm newborn at 2 years

AIM

To evaluate to what extent extremely preterm children (<28 weeks' gestational age) of overweight (BMI 25-29) or obese (BMI ≥30) women are at increased risk of adverse development at 2 years measured with the Bayley Scales of Infant Development II in a multicenter prospective cohort study.

METHODS

Heights and prepregnancy weights of the mothers of 852 preterm born children were collected and included in multinomial logistic regression models.

RESULTS

Compared to newborns born to mothers with normal BMIs, newborns of obese mothers, but not those of overweight mothers, were more likely to have Bayley Scales indices more than 3 standard deviations below the reference mean (mental: OR = 2.1; 95% CI: 1.3, 3.5) (motor: OR = 1.7; 95% CI: 1.1, 2.7). These associations were even more prominent in children who did not have the intermittent or sustained systemic inflammation profile previously shown to be associated with severely impaired development (mental: OR = 4.6; 95% CI: 1.6, 14) (motor: OR = 3.7; 95% CI: 1.5, 8.9).

CONCLUSION

Maternal obesity is associated with an increased risk of impaired offspring development. Some of this impaired development cannot be attributed to confounding due to immaturity, socio-economic correlates or neonatal systemic inflammation.

Lipopolysaccharide-Induced Preconditioning Attenuates Apoptosis and Differentially Regulates TLR4 and TLR7 Gene Expression after Ischemia in the Preterm Ovine Fetal Brain

Acute exposure to subclinical infection modulates subsequent hypoxia-ischemia (HI) injury in a time-dependent manner, likely by cross-talk through Toll-like receptors (TLRs), but the specific pathways are unclear in the preterm-equivalent brain. In the present study, we tested the hypothesis that repeated low-dose exposure to lipopolysaccharide (LPS) before acute ischemia would be associated with induction of specific TLRs that are potentially neuroprotective. Fetal sheep at 0.65 gestation (term is ∼145 days) received intravenous boluses of low-dose LPS for 5 days (day 1, 50 ng/kg; days 2-5, 100 ng/kg) or the same volume of saline. Either 4 or 24 h after the last bolus of LPS, complete carotid occlusion was induced for 22 min. Five days after LPS, brains were collected. Pretreatment with LPS for 5 days decreased cellular apoptosis, microglial activation and reactive astrogliosis in response to HI injury induced 24 but not 4 h after the last dose of LPS. This was associated with upregulation of TLR4, TLR7 and IFN-β mRNA, and increased fetal plasma IFN-β concentrations. The association of reduced white matter apoptosis and astrogliosis after repeated low-dose LPS finishing 24 h but not 4 h before cerebral ischemia, with central and peripheral induction of IFN-β, suggests the possibility that IFN-β may be an important mediator of endogenous neuroprotection in the developing brain.

Association between cerebral palsy and microscopically verified placental infarction in extremely preterm infants

INTRODUCTION

Previously, cerebral palsy has been associated with placental infarctions diagnosed macroscopically by midwifes. However, the risk of misclassification of infarctionsis is high without a histological verification. Therefore, the objective of this study was to study placental histopathology in relation to developmental outcome at 2.5 years corrected age in a population born extremely preterm.

MATERIAL AND METHODS

A prospective cohort study was carried out at Karolinska University Hospital, Stockholm, Sweden on a population of 139 live born infants delivered <27 gestational weeks during 2004-2007. A senior perinatal pathologist, who was blinded to outcome data, evaluated all placental slides microscopically. Neuromotor and sensory functions of the children were evaluated. Bayley Scales of Infant and Toddler Development-III (Bayley-III) were used to assess development at corrected age 2.5 years. The outcome data were evaluated without reference to obstetrical and pathology data. The primary outcome measure was neurological and developmental status at 2.5 years of corrected age. This was measured as diagnosis of cerebral palsy, visual impairment, hearing impairment as well as performance on Bayley-III scales evaluating cognitive, language and motor functions.

RESULTS

Two out of seven children with placental infarction were diagnosed with cerebral palsy compared with one child of 51 without placental infarction (p = 0.036). For developmental outcome according to Bayley-III at 2.5 years no statistically significant associations with placental pathology were found.

CONCLUSION

A possible association between placental infarction, verified by microscopic examination, and cerebral palsy has been identified in this extremely preterm population.

Systems approach to the study of brain damage in the very preterm newborn

Background: A systems approach to the study of brain damage in very preterm newborns has been lacking.

Methods: In this perspective piece, we offer encephalopathy of prematurity as an example of the complexity and interrelatedness of brain-damaging molecular processes that can be initiated inflammatory phenomena.

Results: Using three transcription factors, nuclear factor-kappa B (NF-κB), Notch-1, and nuclear factor erythroid 2 related factor 2 (NRF2), we show the inter-connectedness of signaling pathways activated by some antecedents of encephalopathy of prematurity.

Conclusions: We hope that as biomarkers of exposures and processes leading to brain damage in the most immature newborns become more readily available, those who apply a systems approach to the study of neuroscience can be persuaded to study the pathogenesis of brain disorders in the very preterm newborn.

Neurodevelopmental outcome after extreme prematurity: a review of the literature

BACKGROUND

Advances in obstetric and neonatal medical care and assisted reproductive technology have increased the rates of preterm birth, decreased preterm mortality rates, and lowered the limit of viability. However, morbidity in survivors, including neurodevelopmental disabilities, has increased, especially in extremely preterm infants born at ≤25 weeks' gestation. A better understanding of the prevalence and patterns of adverse neurodevelopmental outcomes in extremely preterm infants is important for patient care, counseling of families, and research.

METHODS

The PubMed and Ovid Medline databases were searched for full text articles published between 1999 and 2013 in English that reported neurodevelopmental outcomes after extreme prematurity, and a review of identified relevant cohort studies was performed.

RESULTS

Extreme prematurity of 22 to 25 weeks' gestation is associated with an overall high mortality of ≥50%. High rates (17% to 59%) of severe neurodevelopmental disabilities occur among survivors on short-term follow-up. The rates of surviving unimpaired or minimally impaired are 6% to 20% for live-born infants at ≤25 weeks' gestation and <5% for infants born at 22 and 23 weeks' gestation. Long-term adverse outcomes after extreme prematurity include intellectual disability (5% to 36%), cerebral palsy (9% to 18%), blindness (0.7% to 9%), and deafness (2% to 4%). Milder degrees of disability involving cognition, behavior, and learning are increasingly recognized among older preterm children, teens, and young adults.

CONCLUSIONS

Infants who are born at ≤25 weeks' gestation, especially those born at 22 and 23 weeks' gestation, have a very low likelihood of surviving little or no impairment. Nearly half of surviving extremely premature infants have significant neurodevelopmental disabilities on short- and long-term follow-up. Instituting early intervention programs, providing family support, and establishing special educational school programs can pay high dividends and lead to brighter futures and, hence, help improve neurodevelopmental outcome of preterm infants.

The enigma of low bilirubin kernicterus in premature infants: why does it still occur, and is it preventable?

Low bilirubin kernicterus in preterm neonates, though rare, remains an unpredictable and refractory form of brain injury. Hypoalbuminemia, co-morbid CNS insult(s), infection, and inflammation are contributing causes that, in many cases, appear to interact in potentiating bilirubin neurotoxicity. Despite compulsive attention to serum bilirubin levels, and clinical and laboratory indices of neurotoxicity risk, low bilirubin kernicterus continues to be seen in contemporary NICUs. While efforts to refine and improve current treatment guidelines are certainly needed, such revision(s) will also have to take into account the risks and benefits of any intervention, including phototherapy.

Low level prenatal blood lead adversely affects early childhood mental development

The effect of prenatal lead exposure on child development has been a topic of public health concern for decades. To estimate prenatal lead exposure effects on early childhood development, maternal blood (n = 364) and umbilical cord blood (n = 224) samples were collected during pregnancy and at delivery. Mental development was assessed using the Harold Ireton Early Child Development Inventory from 174 children. Maternal whole blood lead levels in the first trimester were significantly higher in children with developmental scores <20% than in those with normal scores (mean ± standard deviation: 6.3 ± 1.9 vs 4.0 ± 2.4 µg/dL, respectively, P = .01). Maternal blood lead levels in the first trimester were also inversely associated with the development scores (r = -0.155, P = .041). Logistic regression analysis showed a significant relationship between increasing maternal blood lead levels in the first trimester with low development scores (odds ratio = 1.74, 95% confidence interval = 1.18-2.57, P = .005). The findings of the present study showed a relatively low level of prenatal lead exposure (mean < 6.5 µg/dL) associated with lower developmental scores in early childhood.