Cognitive Outcomes of Children Born Extremely or Very Preterm Since the 1990s and Associated Risk Factors: A Meta-analysis and Meta-regression

Disparities in Kangaroo Care for Premature Infants in the Neonatal Intensive Care Unit

OBJECTIVE

The aim of this study was to investigate whether preterm infants whose families have lower socioeconomic status (SES) or communicate with clinical staff in a language other than English experience differences in the rate, frequency, and duration of kangaroo care (KC) in the neonatal intensive care unit (NICU) compared with preterm infants of higher SES or primarily English-speaking families.

METHODS

Participants were infants born <32 weeks' gestational age (GA), N = 116. We defined SES by the infants' health insurance (private/higher vs public/lower) and language by the language mothers used to communicate with clinical staff (English vs Other language). SES or language groups were compared on (1) rate of KC infants experienced during hospitalization per visitation days, (2) frequency of KC per visitation days, and (3) duration of KC events per day.

RESULTS

Infants in the lower SES and Other language groups experienced KC in reduced amounts, lower frequencies, and shorter durations than infants in either the higher SES or English language groups. SES and language group differences remained significant after controlling for family visitation and GA at birth. After controlling for SES, language group differences in KC duration remained significant.

CONCLUSION

Our findings revealed disparities in the rate, frequency, and duration of KC experienced in the NICU as a function of both SES and language. Such disparities reduced infants' access to this developmental care practice shown to stabilize clinical status and promote neurodevelopment. We recommend that hospital nurseries implement policies that minimize these disparities.

The extremely preterm young adult - State of the art

Recently several studies have reported adult outcomes for individuals born at extremely low gestations, although they tend to be included as part of slightly more mature populations. The growth in collaborative studies allows greater confidence in the identification of persisting risk and allows us to have confidence in the likely outcomes in more contemporary cohorts. This review shows the persistence of adverse outcomes through to adult life and includes a range of outcomes including all body systems evaluated. Nonetheless adult outcomes demonstrate that most survivors appear to be free of major disabling conditions and demonstrate good participation in society. Several studies have reported outcomes in the third decade, but subsequent ageing trajectories have not yet been defined. The stability of many of the outcomes evaluated over childhood into adult life and the lack of improvement in prevalence of childhood impairments found in contemporary cohorts indicates persisting levels of risk.

Initiation and duration of skin-to-skin contact for extremely and very preterm infants: A register study

AIM

This study sought to describe how skin-to-skin contact between extremely and very preterm infants and their parents is practised in Swedish neonatal units.

METHODS

Data from the Swedish Neonatal Quality Register from 2020 to 2021 were extracted to analyse initiation time and daily duration of skin-to-skin contact in different gestational ages and regions.

RESULTS

Of the 1475 infants in the cohort, mean (range) gestational age was 28 weeks (22-31), and mean (range) birthweight was 1205 g (360-2810). For extremely preterm infants (<28 weeks), median (interquartile range) skin-to-skin contact initiation time was at 88 postnatal hours (48-156) and 5% had skin-to-skin contact on the first day. For very preterm infants (<32 weeks), the corresponding numbers were 14 h (4-36) and 34%. Median (interquartile range) daily skin-to-skin contact duration for the entire cohort during the first day, first three and seven days and the remaining hospital stay was 0 (0-0), 0.7 (0-2.7), 1.6 (0.4-3.6) and 4.4 (3.0-6.1) h, respectively.

CONCLUSION

A minority of extremely and very preterm infants were exposed to skin-to-skin contact on the first postnatal day. Daily duration during the first week of life amounted to less than two hours. Initiation time and daily duration varied among gestational ages.

Exposure to Chloramine and Chloroform in Tap Water and Adverse Perinatal Outcomes in Shanghai

Chloramine and chloroform are widespread in tap water due to water disinfection processes. This study was designed to explore the associations between trimester-specific exposure to chloramine and chloroform in tap water and adverse outcomes. This retrospective cohort study included 109,182 mother-infant singleton pairs in Shanghai. A logistic regression model was used to evaluate the associations of chloramine and chloroform concentrations averaged over the whole pregnancy and in each trimester with adverse outcomes, including gestational diabetes mellitus (GDM), gestational hypertensive disorders (GHD), low birthweight (LBW), small for gestational age (SGA), preterm birth (PTB) and prelabor rupture of membranes (PROM). The use of tap water with elevated chloramine levels in the first trimester was associated with GDM (OR = 1.06, 95% CI: 1.03, 1.09), while that in the second trimester was related to GHD (OR = 1.13, 95% CI: 1.09, 1.17). Chloroform levels in the third trimester were associated with LBW (OR = 1.13, 95% CI: 1.09, 1.16), PTB (OR = 1.05, 95% CI: 1.01, 1.08) and PROM (OR = 1.01, 95% CI: 1.00, 1.01). However, tap water chloroform exposure in the second trimester was negatively associated with LBW (OR = 0.95, 95% CI: 0.93, 0.98) and PTB (OR = 0.97, 95% CI: 0.94, 0.99). In conclusion, there are probably no casual associations between current tap water chloroform and chloramine levels and perinatal outcomes. However, more research focusing on the effect of chloramine and chloroform on perinatal outcomes are still warranted.

[Physiotherapy in German Neonatal Intensive Care Units - Indication and Clinical Application of the General Movements Assessments]

BACKGROUND

Standardized recommendations for inpatient and outpatient physiotherapy for preterm infants are lacking in Germany. The aim of this study was to investigate the prescription practice in German neonatal intensive care units. Are standardized assessments used to determine indications? How important is the General Movements Assessment in postnatal diagnostics?

METHODS

We conducted an online survey in German neonatal intensive care units asking 21 questions on indication and prescription practices for inpatient and outpatient physiotherapy in preterm infants' care as well as on General Movements Assessment and its clinical application via Lime Survey.

RESULTS

81% of the participating sites "always" or "often" recommend indication-based inpatient physiotherapy for preterm infants and 53% "always"/"often" recommend outpatient therapy. Indications are mainly based on these symptoms (N=344) or diagnoses (N=273) (multiple answers): hypotonia (94%), abnormal and imbalanced muscle tone (92%), neurological abnormalities (97%) and brain damage (94%). Standardized testing is used by 41% of the participants. The General Movements Assessment is known to 87% of the neonatal intensive care units, 11% use it several times a week, 17% several times a month for indication of physiotherapy.

CONCLUSION

Physiotherapy is frequently prescribed for preterm infants. The majority of indications are based on symptoms or clinical pictures rather than on standardized tests. The General Movements Assessment is a widely known method but not systematically applied at the moment.

Altered functional connectivity in children born very preterm at school age

Children born very preterm are at significant risk of neurodevelopmental impairment. This study sought to identify differences in cognitive function in children born very preterm compared to term-born controls and investigate alteration in white matter microstructure and functional connectivity (FC) based on tract-based spatial statistics (TBSS) and resting-state functional MRI, respectively. At 6 years of age, 36 children born very preterm (< 32 weeks' gestation) without major neurological disabilities and 26 term-born controls were tested using the Wechsler Intelligence Scale for Children, 4th edition, and Child Behavior Checklist. Whole-brain deterministic tractography and FC measurements were performed in both groups. The very preterm group had significantly lower intelligence scores than the term-born controls. The TBSS revealed no significant differences between the two groups, whereas FC was significantly increased between the frontoparietal network and the language network and was significantly decreased between the right salience network nodes in the very preterm group. The altered FC patterns between specific regions of the higher-order networks may reflect underlying deficits in the functional network architecture associated with cognitive function. Further studies are needed to demonstrate a direct connection between FC in these regions and cognitive function.

Immediate skin-to-skin contact may have beneficial effects on the cardiorespiratory stabilisation in very preterm infants

AIM

Our aim was to investigate what effect immediate skin-to-skin contact with a parent had on the cardiorespiratory stabilisation of very preterm infants.

METHODS

This randomised clinical trial was conducted during 2018-2021 at two university hospitals with three neonatal intensive care units in Norway and Sweden. Infants born from 28+0 to 32+6 weeks of gestation were randomised to immediate skin-to-skin contact with a parent for the first six postnatal hours or standard incubator care. The outcome was a composite cardiorespiratory stability score, based on serial measures of heart and respiratory rate, respiratory support, fraction of inspired oxygen and oxygen saturation.

RESULTS

We recruited 91 newborn infants with a mean gestational age of 31+1 (range 28+4-32+6) weeks and mean birth weight of 1534 (range 555-2440) g: 46 received immediate skin-to-skin contact and 45 received incubator care. The group who received skin-to-skin contact had an adjusted mean score of 0.52 higher (95% confidence interval 0.38-0.67, p < 0.001) on a scale from zero to six when compared to the control group.

CONCLUSION

Immediate skin-to-skin contact for the first six postnatal hours had beneficial effects on the cardiorespiratory stabilisation of very preterm infants.

Social-Cognitive Network Connectivity in Preterm Children and Relations With Early Nutrition and Developmental Outcomes

Infants born very low birth weight (VLBW, < 1,500 g) are at a heightened risk for structural brain abnormalities and social-cognitive deficits, which can impair behavioural functioning. Resting-state fMRI, reflecting a baseline level of brain activity and underlying social-cognitive processes, has also been reported to be altered in children born VLBW. Yet very little is known about the functional networks underlying social cognition using magnetoencephalography (MEG) and how it relates to neonatal factors and developmental outcomes. Thus, we investigated functional connectivity at rest in VLBW children and the associations with early nutrition and IQ and behavioural problems. We collected resting-state MEG recordings and measures of IQ and social-cognitive behaviour, as well as macronutrient/energy intakes during initial hospitalisation in 5-year-old children born VLBW (n = 37) compared to full-term (FT; n = 27) controls. We examined resting-state network differences controlling for sex and age at scan. Functional connectivity was estimated using the weighted phase lag index. Associations between functional connectivity with outcome measures and postnatal nutrition were also assessed using regression analyses. We found increased resting-state functional connectivity in VLBW compared to FT children in the gamma frequency band (65–80 Hz). This hyper-connected network was primarily anchored in frontal regions known to underlie social-cognitive functions such as emotional processing. In VLBW children, increased functional connectivity was related to higher IQ scores, while reduced connectivity was related to increased behavioural problems at 5 years of age. These within-group associations were found in the slower frequency bands of theta (4–7 Hz) and alpha (8–12 Hz), frequently linked to higher-order cognitive functions. We also found significant associations between macronutrient (protein and lipid) and energy intakes during the first postnatal month with functional connectivity at preschool-age, highlighting the long-term impacts of postnatal nutrition on preterm brain development. Our findings demonstrate that at preschool-age, VLBW children show altered resting-state connectivity despite IQ and behaviour being in the average range, possibly reflecting functional reorganisation of networks to support social-cognitive and behavioural functioning. Further, our results highlight an important role of early postnatal nutrition in the development of resting-state networks, which in turn may improve neurodevelopmental outcomes in this vulnerable population.

Defective Placentation Syndromes and Intellectual Disability in the Offspring: Nationwide Cohort and Sibling-Controlled Studies

We investigated the relationships between syndromic manifestations of defective placentation and the incidence of intellectual disability (ID) in offspring by conducting a population-based cohort study of 1,581,200 nonmalformed, live singleton infants born in Sweden between 1998 and 2014. Exposures were: 1) placental abruption, 2) preterm preeclampsia (<34 weeks of gestation), 3) preeclampsia combined with infant being small for gestational age (SGA) at birth, and 4) spontaneous preterm birth. The outcome was an ID diagnosis after 3 years of age. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for each syndrome using Cox regression and robust variances. There were 9,451 children with ID (5.5 per 10,000 child-years). ID incidence rates increased with placental abruption (HR = 2.8, 95% CI: 2.3, 3.5), preterm preeclampsia (HR = 3.7, 95% CI: 2.9, 4.7), preeclampsia combined with SGA (HR = 3.3, 95% CI: 2.6, 4.1), and spontaneous preterm birth (for 32-36 and 22-31 weeks, respectively, HR = 1.6 (95% CI: 1.4, 1.8) and 5.2 (95% CI: 4.3, 6.2)). The same pattern of results was evident in sibling-controlled analyses among 1,043,158 full siblings. The strength of associations increased with ID severity. Preterm birth only partly explained the associations of placental abruption, preeclampsia, or SGA with ID. We conclude that defective placentation is related to increased incidence of ID in the offspring.

Effect of antenatal magnesium sulphate on MRI biomarkers of white matter development at term equivalent age: The MagNUM Study

Background

Magnesium sulphate given to women prior to very preterm birth protects the perinatal brain, so fewer babies die or develop cerebral palsy. How magnesium sulphate exerts these beneficial effects remains uncertain. The MagNUM Study aimed to assess the effect of exposure to antenatal magnesium sulphate on MRI measures of brain white matter microstructure at term equivalent age.

Methods

Nested cohort study within the Magnesium sulphate at 30 to <34 weeks’ Gestational age Neuroprotection Trial (MAGENTA). Australian New Zealand Clinical Trials Registry ACTRN12611000491965. Mothers at risk of preterm birth at 30 to <34 weeks’ gestation were randomised to receive either 4 g of magnesium sulphate heptahydrate [8 mmol magnesium ions], or saline placebo, when preterm birth was planned or expected within 24 h. Participating babies underwent diffusion tensor MRI at term equivalent age. The main outcomes were fractional anisotropy across the white matter tract skeleton compared using Tract-based Spatial Statistics (TBSS), with adjustment for postmenstrual age at birth and at MRI, and MRI site. Researchers and families were blind to treatment group allocation during data collection and analyses.

Findings

Of the 109 babies the demographics of the 49 babies exposed to magnesium sulphate were similar to the 60 babies exposed to placebo. In babies whose mothers were allocated to magnesium sulphate, fractional anisotropy was lower within the corticospinal tracts and corona radiata, the superior and inferior longitudinal fasciculi, and the inferior fronto-occipital fasciculi compared to babies whose mothers were allocated placebo (P < 0·05).

Interpretation

In babies born preterm after 30 weeks’ gestation, antenatal magnesium sulphate exposure did not promote development of white matter microstructure in pathways affecting motor or cognitive function. This suggests that if the neuroprotective effect of magnesium sulphate treatment prior to preterm birth is confirmed at this gestation, the mechanisms are not related to accelerated white matter maturation inferred from fractional anisotropy.

Funding

This study was funded by a project grant from the Health Research Council of New Zealand (HRC 14/153).

Severity of Bronchopulmonary Dysplasia and Neurodevelopmental Outcome at 2 and 5 Years Corrected Age

OBJECTIVE

To evaluate the association between bronchopulmonary dysplasia (BPD) severity and risk of neurodevelopmental impairment (NDI) at 2 years and 5 years corrected age and to examine whether this association changes over time.

STUDY DESIGN

This single-center retrospective cohort study included patients with a gestational age <30 weeks surviving to 36 weeks postmenstrual age, divided into groups according to BPD severity. NDI was defined as having cognitive or motor abilities below -1 SD, cerebral palsy, or a hearing or a visual impairment. The association was assessed using a multivariate logistic regression model analysis, adjusting for known confounders for NDI, and mixed-model analysis.

RESULTS

Of the 790 surviving infants (15% diagnosed with mild BPD, 9% with moderate BPD, and 10% with severe BPD), 88% and 82% were longitudinally assessed at 2 years and 5 years corrected age, respectively. The mixed-model analysis showed a statistically significant increase in NDI at all levels of BPD severity compared with infants with no BPD, and a 5-fold increased risk in NDI was seen from 2 years to 5 years corrected age in all degrees of BPD severity. The strength of this association between NDI and BPD severity did not change over time.

CONCLUSIONS

Increased BPD severity is associated with increased risk of NDI at both 2 years and 5 years corrected age. The absolute incidence of NDI increased significantly from 2 years to 5 years corrected age for all BPD severity categories, but this increased risk was similar at both time points in each category.

Latent class growth analysis identified different trajectories in cognitive development of extremely low birthweight children

BACKGROUND

Recent longitudinal studies suggest stable cognitive development in preterm children, although with great individual variation. This prospective neurocognitive follow-up study of extremely low birthweight (ELBW, <1000 g) children aimed to characterise groups with different developmental trajectories from preschool to preteen age.

METHODS

ELBW children (n=115) born in Finland in 1996-1997 participated in cognitive assessments at a median age of 5.0 years and 11.3 years. A standardised test of intelligence (Wechsler Preschool and Primary Scale of Intelligence-Revised or Wechsler Intelligence Scale for Children-third edition) was administered at both ages.

RESULTS

Three ELBW groups with different developmental trajectories over time were identified with latent class growth analysis. Children with average (Full-Scale IQ (FSIQ): 85-115) and below average (FSIQ: <85) intelligence at 5 years of age had significant decreases in intelligence scores by 11 years of age (-11.7 points and -14.9 points, respectively, both p<0.001), while those with above average intelligence (FSIQ: >115) showed stable development (-3.2 points, p=0.250). Multiple linear regression showed that neonatal complications (intraventricular haemorrhage grade 3-4 and blood culture positive sepsis) and maternal education significantly predicted lower intelligence at the second assessment (F(3,106)=7.27, p<0.001, adjusted R²=0.147).

CONCLUSIONS

ELBW children represent a heterogeneous patient population in which groups with different cognitive trajectories can be detected. Deterioration may occur particularly in children with initial average or below average cognitive performance at 5 years of age, with neonatal complications and lower maternal education presenting as risk factors. Catch-up in cognitive functions seems more uncommon in the ELBW population, which should be noted in clinical work.

Platelet is the early predictor of bronchopulmonary dysplasia in very premature infants: an observational cohort study

Background

A previous study showed that the lungs are involved in the biogenesis of platelets (PLTs). Thus, the present study aimed to investigate the association between bronchopulmonary dysplasia (BPD), a chronic lung disease, and PLT parameters in very premature infants.

Methods

The study subjects were premature infants with a gestational age of ≤ 30 weeks and birth weight of ≤ 1500 g in a preterm birth cohort study recruited between January 1, 2015, and August 31, 2019. BPD was defined as the need for oxygen supplementation more than 28 days after birth. The PLT count, mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) level were compared between BPD and non-BPD infants. A generalized estimating equation model was used to adjust for confounding factors. A forward stepwise logistic regression model was used to calculate the adjusted odds ratio (OR) for thrombocytopenia in the BPD group. Receiver operating characteristic curve analysis was performed to assess the predictive value of PLT count combined with gestational age (GA) and birth weight (BW) for BPD.

Results

The final study subjects were 134 very premature infants, namely, 64 infants with BPD and 70 infants without BPD. The BPD infants had lower PLT counts (F = 4.44, P = 0.03) and PCT levels (F = 12.54, P = 0.00) than the non-BPD infants. However, the MPV (F = 14.25, P = 0.00) and PDW (F = 15.04, P = 0.00) were higher in the BPD group. After adjusting for potential confounding factors, the BPD infants had a higher risk of thrombocytopenia than the non-BPD infants (adjusted aOR 2.88, 95% CI 1.01–8.15), and the risk of BPD was increased in very premature infants with a PLT count ≤ 177*10⁹/L (OR 4.74, 95% CI 1.93–11.62) at the end of the second week. In the multivariate predictive model, it was showed that the AUC area (0.85), sensitivity (0.88), specificity (0.70) and Youden index (0.58) are improved using PLT counts ≤ 177*10⁹/L combined with GA and BW.

Conclusions

Abnormal PLT parameters were observed in BPD infants, and a PLT count ≤ 177*10⁹/L was a potential risk factor for the development of BPD in very premature infants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01895-2.

Innovative computational approaches shed light on genetic mechanisms underlying cognitive impairment among children born extremely preterm

BACKGROUND

Although survival rates for infants born extremely preterm (gestation < 28 weeks) have improved significantly in recent decades, neurodevelopmental impairment remains a major concern. Children born extremely preterm remain at high risk for cognitive impairment from early childhood to adulthood. However, there is limited evidence on genetic factors associated with cognitive impairment in this population.

METHODS

First, we used a latent profile analysis (LPA) approach to characterize neurocognitive function at age 10 for children born extremely preterm. Children were classified into two groups: (1) no or low cognitive impairment, and (2) moderate-to-severe cognitive impairment. Second, we performed TOPMed-based genotype imputation on samples with genotype array data (n = 528). Third, we then conducted a genome-wide association study (GWAS) for LPA-inferred cognitive impairment. Finally, computational analysis was conducted to explore potential mechanisms underlying the variant x LPA association.

RESULTS

We identified two loci reaching genome-wide significance (p value < 5e-8): TEA domain transcription factor 4 (TEAD4 at rs11829294, p value = 2.40e-8) and syntaxin 18 (STX18 at rs79453226, p value = 1.91e-8). Integrative analysis with brain expression quantitative trait loci (eQTL), chromatin conformation, and epigenomic annotations suggests tetraspanin 9 (TSPAN9) and protein arginine methyltransferase 8 (PRMT8) as potential functional genes underlying the GWAS signal at the TEAD4 locus.

CONCLUSIONS

We conducted a novel computational analysis by utilizing an LPA-inferred phenotype with genetics data for the first time. This study suggests that rs11829294 and its LD buddies have potential regulatory roles on genes that could impact neurocognitive impairment for extreme preterm born children.

Growth in extremely preterm children born in England in 1995 and 2006: the EPICure studies

OBJECTIVES

To determine growth outcomes at 11 years of age in children born <27 weeks of gestation in England in 2006 (EPICure2) and to compare growth from birth to 11 years of age for births<26 weeks with those in England in 1995 (EPICure).

METHODS

200 EPICure2 children assessed at 11 years alongside 143 term-born controls. Growth measures from birth to 11 years were compared for births<26 weeks between EPICure2 (n=112) and EPICure (n=176). Growth parameter z-scores were derived from 1990 UK standards.

RESULTS

Among EPICure2 children, mean z-scores for height and weight were close to the population standards (0.08 and 0.18 SD, respectively) but significantly below those of controls: difference in mean (Δ) z-scores for weight -0.42 SD (95% CI -0.68 to -0.17), for height -0.45 SD (-0.70 to -0.20) and for head circumference (HC) -1.05 SD (-1.35 to -0.75); mean body mass index (BMI) z-score in EPICure2 children was 0.18 SD, not significantly different from controls (0.43 SD, p=0.065). Compared with EPICure, EPICure2 children born <26 weeks at 11 years had higher z-scores for weight (Δ 0.72 (0.47, 0.96)), height (Δ 0.55 (0.29, 0.81)) and BMI (Δ 0.56 (0.24, 0.87)), which were not fully explained by perinatal/demographic differences between eras. Weight catch-up was greater from term-age to 2.5/3 years in EPICure2 than in EPICure (1.25 SD vs 0.53 SD; p<0.001). Poor HC growth was observed in EPICure2, unchanged from EPICure.

CONCLUSIONS

Since 1995, childhood growth in weight, height and BMI have improved for births <26 weeks of gestation, but there was no improvement in head growth.

Neurodevelopmental Outcomes of Very-Low-Birth-Weight Infants without Severe Brain Lesions and Impact of Postnatal Steroid Use: A Single-Center Korean Study

Purpose: We used the Bayley Scales of Infant and Toddler Development (BSID)-III to analyze the incidence and risk factors of developmental delay in very-low-birth-weight infants without severe brain lesions. We further examined the correlation between the cumulative dexamethasone dose and developmental assessment results.Methods: We retrospectively analyzed data of preterm infants (birth weight <1,500 g) admitted to our neonatal intensive care unit between January 2014 to December 2020. The BSID-III scores obtained between the corrected ages of 12 and 24 months and after 24 months were analyzed. Developmental delay was defined as a composite score of <85 for the cognition, language, and motor domains. Univariate and multivariate analyses of developmental delay risk factors and developmental changes from the first to second BSID-III were performed. Correlations between the accumulated dexamethasone dose used for bronchopulmonary dysplasia (BPD) and the first and second test scores were analyzed.Results: Seventy-one and thirty-six infants completed the first and second tests, respectively. In both tests, developmental delay was most commonly observed in the language domain (26.8%, 47.2%). In multivariate analysis, mild BPD was identified as a developmental delay risk factor (P<0.05), whereas prenatal steroid use reduced the developmental delay risk (P<0.05). All domain scores were lower in the second test than in the first test. The cognition and language domain scores in the second test decreased with increasing cumulative dexamethasone doses.Conclusion: Very-low-birth-weight infants typically experience language delay, which can persist as they age.

Longitudinal Serum Metabolomics in Extremely Premature Infants: Relationships With Gestational Age, Nutrition, and Morbidities

An increasing number of extremely premature infants survive the neonatal period and beyond. Little is known about the maturation of the preterm infant’s metabolome and its relation to the development of morbidities. Using 1H-NMR, we investigated the serum metabolic profile of 87 infants born at a gestational age (GA) <28 weeks [mean GA (SD) 25.4 (1.4) weeks] in samples longitudinally collected from birth to term equivalent age. The infant metabolome was analyzed in relation to GA, postnatal age, nutrition, and preterm morbidities. At postnatal day 1, low GA correlated with high levels of 3-hydroxyisobutyrate, acetate, acetoacetate, acetone, formate, glucose, and valine. Nearly all quantified metabolites displayed postnatal concentration changes. For example, the two phospholipid-related metabolites myo-inositol and ethanolamine displayed a similar decline from birth over the first weeks of life, irrespectively of GA. The proportion of enteral/parenteral energy intake in the first 28 days significantly correlated with mean levels of 52% of the analyzed metabolites. Low enteral energy intake was associated with high serum levels of 3-hydroxyisobutyrate, creatinine, glucose, glycerol, histidine, lactate, leucine, lysine, methionine, ornithine, phenylalanine, proline, threonine, and uridine. There were also significant correlations between high enteral intake and high serum levels of isoleucine and tyrosine. Retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) outcomes were not significantly associated with metabolite levels in the neonatal period after correcting for multiple testing. In conclusion, the serum metabolome of extremely premature infants changes substantially in the neonatal period, largely driven by the gradual transfer from total parenteral nutrition to full enteral feeding. Further studies are needed to disentangle the intricate relationships between the metabolome, nutritional management, GA, and the development of preterm morbidities.

Neurobehavioral Phenotype and Dysexecutive Syndrome of Preterm Children: Comorbidity or Trigger? An Update

Premature birth is a worldwide public health priority. One in ten children is born before 37 weeks of gestational age and, in developed countries, survival rates without major neonatal morbidity are increasing. Although severe sequelae associated with these births have decreased, their neurobehavioral difficulties, often associated in multiple fields, remain stable but still widespread. These neurobehavioral difficulties hamper the normal development of academic achievements and societal integration and intensify the children's needs for rehabilitation during their preschool and academic years. Severe sequelae increase when gestational age decreases. This is even truer if the socio-cultural background is impeded by low income, education and language skills as compared with defined averages. However, moderate and/or minor neurocognitive and/or behavioral difficulties are almost identical for a moderate or a late preterm birth. Obtaining a better clinical description of neurobehavioral characteristics of those pretermly born, once they reach preschool age, is essential to detect behavioral issues as well as early specific cognitive difficulties (working memory, planning, inhibition, language expression and reception, attention and fine motor skills, etc.). Such information would provide a better understanding of the executive functions' role in brain connectivity, neurodevelopment and neuroanatomical correlation with premature encephalopathy.

A feasibility randomized controlled trial of a NICU rehabilitation program for very low birth weight infants

Motor disability is common in children born preterm. Interventions focusing on environmental enrichment and emotional connection can positively impact outcomes. The NICU-based rehabilitation (NeoRehab) program consists of evidence-based interventions provided by a parent in addition to usual care. The program combines positive sensory experiences (vocal soothing, scent exchange, comforting touch, skin-to-skin care) as well as motor training (massage and physical therapy) in a gestational age (GA) appropriate fashion. To investigate the acceptability, feasibility and fidelity of the NeoRehab program in very low birthweight (VLBW) infants. All interventions were provided by parents in addition to usual care. Infants (≤ 32 weeks' GA and/or ≤ 1500 g birthweight) were enrolled in a randomized controlled trial comparing NeoRehab to usual care (03/2019-10/2020). The a priori dosing goal was for interventions to be performed 5 days/week. The primary outcomes were the acceptability, feasibility and fidelity of the NeoRehab program. 36 participants were randomized to the intervention group and 34 allocated to usual care. The recruitment rate was 71% and retention rate 98%. None of the interventions met the 5 days per week pre-established goal. 97% of participants documented performing a combination of interventions at least 3 times per week. The NeoRehab program was well received and acceptable to parents of VLBW infants. Programs that place a high demand on parents (5 days per week) are not feasible and goals of intervention at least 3 times per week appear to be feasible in the context of the United States. Parent-provided motor interventions were most challenging to parents and alternative strategies should be considered in future studies. Further studies are needed to evaluate the relationship between intervention dosing on long term motor outcomes.

Do small baby units improve extremely premature infant outcomes?

Increasing numbers of neonatal intensive care units have formed small baby units or small baby teams with the intention to optimize care of extremely premature infants. Considerable time, energy, and resources are required to develop and sustain complex quality improvement constructs, so legitimate questions about effectiveness, unintended consequences, and lost opportunity costs warrant scrutiny. The small baby unit literature is diminutive. Errors of chance, bias, and confounding secondary to insufficient definitions of process and outcome metrics, overlapping quality improvement projects, and limited cost analyses restrict firm conclusions. Well-established quality improvement methodologies such as evidence-based guidelines, standardized variability reduction using measurement-and-adjust techniques, family-integrated focus, and developmentally sensitive care, reliably improve outcomes for all-sized premature infants. There is not compelling published evidence that adding specialized small baby units or designated teams for extremely premature infants further enhances short- or long-term health if robust quality improvement fundamentals are already imbedded within local culture.

The Aryl Hydrocarbon Receptor (AHR): A Novel Therapeutic Target for Pulmonary Diseases?

The aryl hydrocarbon receptor (AHR) is a cytoplasmic transcription factor that is well-known for regulating xenobiotic metabolism. Studies in knockout and transgenic mice indicate that the AHR plays a vital role in the development of liver and regulation of reproductive, cardiovascular, hematopoietic, and immune homeostasis. In this focused review on lung diseases associated with acute injury and alveolar development, we reviewed and summarized the current literature on the mechanistic role(s) and therapeutic potential of the AHR in acute lung injury, chronic obstructive pulmonary disease, and bronchopulmonary dysplasia (BPD). Pre-clinical studies indicate that endogenous AHR activation is necessary to protect neonatal and adult lungs against hyperoxia- and cigarette smoke-induced injury. Our goal is to provide insight into the high translational potential of the AHR in the meaningful management of infants and adults with these lung disorders that lack curative therapies.

Maternal education and cognitive development in 15 European very-preterm birth cohorts from the RECAP Preterm platform

BACKGROUND

Studies are sparse and inconclusive about the association between maternal education and cognitive development among children born very preterm (VPT). Although this association is well established in the general population, questions remain about its magnitude among children born VPT whose risks of medical and developmental complications are high. We investigated the association of maternal education with cognitive outcomes in European VPT birth cohorts.

METHODS

We used harmonized aggregated data from 15 population-based cohorts of children born at <32 weeks of gestational age (GA) or <1500 g from 1985 to 2013 in 13 countries with information on maternal education and assessments of general development at 2-3 years and/or intelligence quotients between 4 and 15 years. Term-born controls (≥37 weeks of GA) were available in eight cohorts. Maternal education was classified as: low (primary/lower secondary); medium (upper secondary/short tertiary); high (bachelor's/higher). Pooled standardized mean differences (SMDs) in cognitive scores were estimated (reference: high educational level) for children assessed at ages 2-3, 4-7 and 8-15 years.

RESULTS

The study included 10 145 VPT children from 12 cohorts at 2-3 years, 8829 from 12 cohorts at 4-7 years and 1865 children from 6 cohorts at 8-15 years. Children whose mothers had low, compared with high, educational attainment scored lower on cognitive measures [pooled unadjusted SMDs: 2-3 years = -0.32 (95% confidence intervals: -0.43 to -0.21); 4-7 years = -0.57 (-0.67; -0.47); 8-15 years = -0.54 (-0.72; -0.37)]. Analyses by GA subgroups (<27 vs ≥27 weeks) in children without severe neonatal morbidity and term controls yielded similar results.

CONCLUSIONS

Across diverse settings and regardless of the degree of prematurity, low maternal education was associated with lower cognition.

Bronchopulmonary Dysplasia and Risk of Developmental Delay: An EPIPAGE-2 Cohort Study

BACKGROUND

Overall and respiratory management of preterm children are constantly evolving, which might have changed both the pathophysiology and neurodevelopmental consequences of bronchopulmonary dysplasia (BPD).

OBJECTIVES

The objective of this study is to determine whether the previously shown association between BPD and risk of developmental delay persists.

METHODS

The study population was children born before 32 weeks' gestation from the French prospective cohort EPIPAGE-2. The exposure was BPD assessed at 36 weeks' postmenstrual age. The main outcome was risk of developmental delay defined by an Age &amp; Stages Questionnaires (ASQ) score below threshold at 24 months' corrected age.

RESULTS

The analyzed population included 2,706 children. Among those with available ASQ score, 196/1,587 had BPD and 671/1,587 had an ASQ score below threshold. BPD was associated with an ASQ score below threshold (odds ratio 1.52, 95% confidence interval 1.11-2.08; p = 0.008).

CONCLUSIONS

BPD was strongly associated with risk of developmental delay.

Treatment status of extremely premature infants with gestational age < 28 weeks in a Chinese perinatal center from 2010 to 2019

BACKGROUND

There is a paucity of studies conducted in China on the outcomes of all live-birth extremely premature infants (EPIs) and there is no unified recommendation on the active treatment of the minimum gestational age in the field of perinatal medicine in China. We aimed to investigate the current treatment situation of EPIs and to provide evidence for formulating reasonable treatment recommendations.

METHODS

We established a real-world ambispective cohort study of all live births in delivery rooms with gestational age (GA) between 24⁺⁰ and 27⁺⁶ weeks from 2010 to 2019.

RESULTS

Of the 1163 EPIs included in our study, 241 (20.7%) survived, while 849 (73.0%) died in the delivery room and 73 (6.3%) died in the neonatal intensive care unit. Among all included EPIs, 862 (74.1%) died from withholding or withdrawal of care. Regardless of stratification according to GA or birth weight, the proportion of total mortality attributable to withdrawal of care is high. For infants with the GA of 24 weeks, active treatment did not extend their survival time (P = 0.224). The survival time without severe morbidity of the active treatment was significantly longer than that of withdrawing care for infants older than 25 weeks (P < 0.001). Over time, the survival rate improved, and the withdrawal of care caused by socioeconomic factors and primary nonintervention were reduced significantly (P < 0.001).

CONCLUSIONS

The mortality rate of EPIs is still high. Withdrawal of care is common for EPIs with smaller GA, especially in the delivery room. It is necessary to use a multi-center, large sample of real-world data to find the survival limit of active treatment based on our treatment capabilities.

Early Mental Trajectories Predict Different Cognitive Levels at School Age in Very Preterm Children

INTRODUCTION

Early identification of preterm children at high risk of intellectual disability (intelligence quotient [IQ] <70) or borderline intelligence (IQ = 70-84) is critical for different early intervention. We investigated whether early-life mental trajectories predict intellectual disability and borderline intelligence, respectively, among school-age preterm children.

METHODS

A multicenter study recruited preterm infants born at <32 weeks' gestation between 2001 and 2014 in Taiwan who underwent mental assessments (Bayley Scales of Infant Development) at corrected ages 6, 12, and 24 months and IQs at age 5.5 years. Mental trajectories from ages 6 to 24 months determined using group-based trajectory modeling were employed to predict intellectual disability and borderline intelligence, respectively. Model fit was assessed using the area under the receiver operating characteristic curve (AUROC) and Akaike information criterion (AIC).

RESULTS

Among the 1,680 children enrolled, three mental trajectories were identified: high-stable (59.7%), high-declining (35.3%), and low-declining (5.0%), in which the borderline-intelligence/intellectual-disability rate was 14.1%/1.5%, 36.1%/13.7%, and 10.7%/82.1%, respectively. Compared with children with normal intelligence, the low-declining trajectory had 37.7-fold higher odds (95% confidence interval [CI], 26.3-48.1) for intellectual disability, and the high-declining trajectory had 4.4-fold higher odds (95% CI, 3.1-6.1) for borderline intelligence. Compared to the models with risk factors alone (AIC 1,791.2), the models that included both risk factors and trajectory groups had better overall performance (AIC 1,419.8) and increased prediction power for intelligence outcomes: low-declining trajectory for intellectual disability (AUROC increased from 0.81 to 0.92) and high-declining trajectory for borderline intelligence (AUROC increased from 0.68 to 0.75).

CONCLUSIONS

Early-life mental trajectories help identify preterm children at risk of intellectual disability and borderline intelligence, respectively, at school age for timely intervention.

Feasibility of portable capnometer for mechanically ventilated preterm infants in the delivery room

This study aimed to determine whether a specific portable capnometer (EMMA™) can facilitate the maintenance of an appropriate partial pressure of arterial carbon dioxide (PaCO₂) in intubated preterm infants in the delivery room. This study included preterm infants with a gestational age of 26 + 0 to 31 + 6 weeks who required intubation in the delivery room. We prospectively identified 40 infants who underwent the EMMA™ monitoring intervention group and 43 infants who did not undergo monitoring (historical control group). PaCO₂ was evaluated either at admission in the neonatal intensive care unit or at 2 h after birth. The proportion of infants with an appropriate PaCO₂ (35-60 mmHg) was greater in the intervention group than in the control group (80% vs. 42%; p = 0.001). There were no significant differences in the rate of accidental extubation (5.0% vs. 7.0%, p = 1.00) or in the proportion of infants with an appropriate PaCO₂ among infants whose birth weight was < 1000 g (54% vs. 40%, p = 0.49). However, among infants whose birth weight was ≥ 1000 g, the PaCO₂ tended to be more appropriate in the intervention group than in the control group (93% vs. 44%; p < 0.001).Conclusion: The EMMA™ facilitated the maintenance of an appropriate PaCO₂ for mechanically ventilated preterm infants, especially infants with birth weight ≥1000 g, in the delivery room. What is Known: • An inappropriate partial pressure of arterial carbon dioxide has been associated with intraventricular hemorrhage in preterm infants. • There is a need to appropriately control the partial pressure of arterial carbon dioxide in preterm infants. What is New: • This is the first report regarding the feasibility of a portable capnometer, the EMMA™, in the delivery room. • The EMMA™ may be considered a feasible monitoring device in the delivery room for intubated preterm infants, especially infants with birth weight ≥1000 g.

Language function following preterm birth: prediction using machine learning

BACKGROUND

Preterm birth can lead to impaired language development. This study aimed to predict language outcomes at 2 years corrected gestational age (CGA) for children born preterm.

METHODS

We analysed data from 89 preterm neonates (median GA 29 weeks) who underwent diffusion MRI (dMRI) at term-equivalent age and language assessment at 2 years CGA using the Bayley-III. Feature selection and a random forests classifier were used to differentiate typical versus delayed (Bayley-III language composite score <85) language development.

RESULTS

The model achieved balanced accuracy: 91%, sensitivity: 86%, and specificity: 96%. The probability of language delay at 2 years CGA is increased with: increasing values of peak width of skeletonized fractional anisotropy (PSFA), radial diffusivity (PSRD), and axial diffusivity (PSAD) derived from dMRI; among twins; and after an incomplete course of, or no exposure to, antenatal corticosteroids. Female sex and breastfeeding during the neonatal period reduced the risk of language delay.

CONCLUSIONS

The combination of perinatal clinical information and MRI features leads to accurate prediction of preterm infants who are likely to develop language deficits in early childhood. This model could potentially enable stratification of preterm children at risk of language dysfunction who may benefit from targeted early interventions.

IMPACT

A combination of clinical perinatal factors and neonatal DTI measures of white matter microstructure leads to accurate prediction of language outcome at 2 years corrected gestational age following preterm birth. A model that comprises clinical and MRI features that has potential to be scalable across centres. It offers a basis for enhancing the power and generalizability of diagnostic and prognostic studies of neurodevelopmental disorders associated with language impairment. Early identification of infants who are at risk of language delay, facilitating targeted early interventions and support services, which could improve the quality of life for children born preterm.

Autologous cord blood mononuclear cell infusion for the prevention of bronchopulmonary dysplasia in very preterm monozygotic twins: A study protocol for a randomized, placebo-controlled, double-blinded multicenter trial

BACKGROUND

Preterm-associated complications remain the main cause of neonatal death. Survivors face the challenges of short- and long-term complications. Among all complications, bronchopulmonary dysplasia (BPD) remains the first important cause of neonatal mortality and morbidity. Current treatment does not address this main preterm complication. Cord blood is regarded as a convenient source of stem cells. The paracrine bioactive factors of stem cells contribute to tissue repair and immune modulation. Our clinical studies and those of others have shown that cord blood cell infusion is both safe and possibly effective in the prevention and treatment of BPD. The therapeutic use of cord blood has emerged as a promising therapy. However, the genetic heterogeneity between control and intervention groups may reduce the comparability especially among small sample trials. The purpose of this study protocol is to investigate the effects of autologous cord blood mononuclear cell (ACBMNC) infusion on the prevention of BPD in very preterm monozygotic twins of less than 32 gestation weeks.

METHODS

In this prospective, randomized, placebo-controlled, double-blinded multicenter clinical trial, 60 pairs of monozygotic twin preterm neonates of less than 32 weeks admitted to the Neonatal Intensive Care Unit are randomly assigned to receive intravenous ACBMNC infusion (targeted at 5 × 10⁷ cells/kg) or placebo (normal saline) within 24 h after birth in a 1:1 ratio. The primary outcome will be survival without BPD at 36 weeks of postmenstrual age. The secondary outcomes will include the mortality rate, BPD severity, other common preterm complication rates, respiratory support duration, length and cost of hospitalization, and long-term respiratory and neurodevelopmental outcomes during a 2-year follow-up. Furthermore, we will perform single-cell RNA sequencing for cord blood cells and blood cells 3-10 days after intervention and detect whether reactive oxygen species and inflammatory cytokines are present.

CONCLUSION

This will be the first randomized, placebo-controlled, double-blinded trial to evaluate the efficacy of ACBMNC infusion to prevent BPD in monozygotic twin premature infants and investigate the underlying protective mechanisms. The results of this trial will provide valuable clinical evidence for translational application of cord blood cell therapy in very preterm infants.Trial registration: ClinicalTrials.gov, NCT05087498, registered 10/09/2021, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S000BAD7&selectaction=Edit&uid=U0002PLA&ts=2&cx=qvyylv.

Gestational Age, Parent Education, and Education in Adulthood

BACKGROUND

Adults born preterm (<37 weeks) have lower educational attainment than those born term. Whether this relationship is modified by family factors such as socioeconomic background is, however, less well known. We investigated whether the relationship between gestational age and educational attainment in adulthood differed according to parents' educational level in 4 Nordic countries.

METHODS

This register-based cohort study included singletons born alive from 1987 up to 1992 in Denmark, Finland, Norway, and Sweden. In each study population, we investigated effect modification by parents' educational level (low, intermediate, high) on the association between gestational age at birth (25-44 completed weeks) and low educational attainment at 25 years (not having completed upper secondary education) using general estimation equations logistic regressions.

RESULTS

A total of 4.3%, 4.0%, 4.8%, and 5.0% singletons were born preterm in the Danish (n = 331 448), Finnish (n = 220 095), Norwegian (n = 292 840), and Swedish (n = 513 975) populations, respectively. In all countries, both lower gestational age and lower parental educational level contributed additively to low educational attainment. For example, in Denmark, the relative risk of low educational attainment was 1.84 (95% confidence interval 1.44 to 2.26) in adults born at 28 to 31 weeks whose parents had high educational level and 5.25 (95% confidence interval 4.53 to 6.02) in adults born at 28 to 31 weeks whose parents had low educational level, compared with a reference group born at 39 to 41 weeks with high parental educational level.

CONCLUSIONS

Although higher parental education level was associated with higher educational attainment for all gestational ages, parental education did not mitigate the educational disadvantages of shorter gestational age.

Retinal ganglion cell complex thickness at school-age, prematurity and neonatal stressors

PURPOSE

To investigate the association between the ganglion cell complex (GCC) thickness at early school-age and prematurity and other neonatal factors.

METHODS

Cross-sectional study. The sample included very preterm children with gestational age (GA) below 32 weeks or birthweight below 1500 g enrolled in a follow-up program (n = 101) and a comparison group of term-born children (n = 49). Ganglion cell complex (GCC) thickness was measured at 4-8 years using high-quality optical coherence tomography (OCT) images. Data on neonatal and postnatal features were extracted from clinical records; analyses included mixed linear models.

RESULTS

Ganglion cell layer (GCL) and retinal nerve fiber layer (mRNFL) were thicker in term than in preterm born children (2.9 μm and 2.4 μm respectively, p < 0.001). Within the preterm group, lower GA was associated with a decrease in total GCL (0.7 μm per week, p < 0.001). Being small for GA was associated with further thinning in both layers (1.4 and 2.8 µm). Postnatal corticosteroids therapy and severe brain lesion were associated with thinning in the total GCL of 6 µm (p < 0.001) and 4.1 µm (p = 0.002), respectively, and shock was associated with thinning in total mRNFL of 6 µm (p < 0.001).

CONCLUSIONS

Lower GA or birthweight are associated with thinning of GCC layers. When performing an OCT examination at school-age and a decrease in GCC thickness is observed, it may be relevant to ask about a history of prematurity, and further enquire about neonatal shock, postnatal corticosteroids therapy or severe brain lesion that are related to additional decrease in GCC thickness.

Cognitive and academic outcomes of children born extremely preterm

Extremely preterm birth is associated with increased risk for a spectrum of neurodevelopmental problems. This review describes the nature of cognitive and academic outcomes of extremely preterm survivors across childhood and adolescence. Evidence across meta-analyses and large prospective birth cohorts indicate that early developmental difficulties in children born extremely preterm do not resolve with age and are not improving over time despite advancements in neonatal care. While extremely preterm birth confers increased risk of widespread cognitive difficulties, considerable heterogeneity in outcomes is evident across individuals. There is a continued need for high-quality longitudinal studies to understand the developmental progression of cognitive and academic skills following extremely preterm birth, and greater focus on understanding contributing factors that may help to explain the individual variability in cognitive and academic outcomes of extremely preterm survivors.

Contrast-Enhanced Brain Ultrasound Perfusion Metrics in the EXTra-Uterine Environment for Neonatal Development (EXTEND): Correlation With Hemodynamic Parameters

OBJECTIVES

Contrast-enhanced ultrasound (CEUS) can provide quantitative perfusion metrics and may be useful to detect cerebral pathology in neonates and premature infants, particularly in extrauterine environments. The effect of hemodynamics on cerebral perfusion metrics is unknown, which limits the clinical application of this technology. We aimed to determine associations between systemic hemodynamics and concurrently measured brain perfusion parameters in an animal model of extrauterine support.

METHODS

Nine fetal lambs were transferred to an extrauterine support device. Lumason® ultrasound contrast (0.1-0.3 ml) was administered via the umbilical vein and 90-second cine clips were obtained. Time-intensity-curves (TICs) were generated and time-dependent and area-under-curve (AUC) parameters were derived. Associations between brain perfusion metrics and hemodynamics including heart rate (HR) and mean arterial pressure (MAP) were evaluated by multilevel linear mixed-effects models.

RESULTS

Eighty-six ultrasound examinations were performed and 72 examinations were quantifiable. Time-dependent measurements were independent of all hemodynamic parameters (all p ≥.05). Oxygen delivery and mean blood flow were correlated with AUC measurements (all p ≤.01). Physiologic HR and MAP were not correlated with any measurements (all p ≥.05).

CONCLUSION

Detected aberrations in time-dependent CEUS measurements are not correlated with hemodynamic parameters and are thought to reflect the changes in cerebral blood flow, thus providing a promising tool for evaluation of brain perfusion. CEUS brain perfusion parameters are not correlated with physiologic HR and MAP, but AUC-dependent measurements are correlated with oxygen delivery and blood flow, suggesting that CEUS offers additional value over standard monitoring. Overall, these findings enhance the applicability of this technology.

Motor outcomes of children born extremely preterm; from early childhood to adolescence

Children and adolescents born extremely preterm (EP; <28 weeks' gestation) are at greater risk of motor impairment, including cerebral palsy and developmental coordination disorder, than their term born peers. Importantly, motor impairment has implications beyond performing motor skills; it negatively affects outcomes as diverse as school success, emotional wellbeing, physical health, and physical activity (PA) participation. This review will outline what is known about PA participation across childhood and adolescence for children born EP and term, recognising that PA may improve physical, social, and mental health outcomes. Critically, PA participation occurs in the context of children's and adolescents' daily lives, and is influenced by the family, social and physical environment, as well as by the child's personal factors, such as motor impairment. Further research is needed to better understand PA participation levels and correlates for children and adolescents born preterm, to better inform effective and sustainable interventions.

Outcomes into adulthood of infants born extremely preterm

As survival of infants born extremely preterm increases, more are now reaching adulthood. It is well documented that survivors born extremely preterm experience more developmental delay and disability in multiple domains compared with term-born controls in early childhood and school age. However, with increasing age, health problems involving physical and mental health become more evident. Despite these challenges, it is reassuring that self-reported quality of life remains good. Future directions of research include development of age-appropriate interventions to optimise health and development of individuals born extremely preterm beyond school age.

Predictors of long-term neurodevelopmental outcomes of children born extremely preterm

Children born extremely preterm (<28 weeks' gestation) are at high risk of a range of adverse neurodevelopmental outcomes in later childhood compared with their peers born at term, including cognitive, motor, and behavioral difficulties. These difficulties can be associated with poorer academic achievement and health outcomes at school age. In this review, we discuss several predictors in the newborn period of early childhood neurodevelopmental outcomes including perinatal risk factors, neuroimaging findings and neurobehavioral assessments, along with social and environmental influences for children born extremely preterm. Given the complexity of predicting long-term outcomes in children born extremely preterm, we recommend multi-disciplinary teams in clinical practice to assist in determining an individual child's risk for adverse long-term outcomes and need for referral to targeted intervention, based upon their risk.

Association between Intermittent Hypoxemia and Severe Bronchopulmonary Dysplasia in Preterm Infants

Rationale: Bronchopulmonary dysplasia increases the risk of disability in extremely preterm infants. Although the pathophysiology remains uncertain, prior exposure to intermittent hypoxemia may play a role in this relationship. Objectives: To determine the association between prolonged episodes of intermittent hypoxemia and severe bronchopulmonary dysplasia. Methods: A post hoc analysis of extremely preterm infants in the Canadian Oxygen Trial who survived to 36 weeks' postmenstrual age was performed. Oxygen saturations <80% for ⩾1 minute and the proportion of time per day with hypoxemia were quantified using continuous pulse oximetry data that had been sampled every 10 seconds from within 24 hours of birth until 36 weeks' postmenstrual age. The study outcome was severe bronchopulmonary dysplasia as defined in the 2001 NIH Workshop Summary. Measurements and Main Results: Of 1,018 infants, 332 (32.6%) developed severe bronchopulmonary dysplasia. The median number of hypoxemic episodes ranged from 0.8/day (interquartile range, 0.2-1.1) to 60.2/day (interquartile range, 51.4-70.3) among the least and most affected 10% of infants. Compared with the lowest decile of exposure to hypoxemic episodes, the adjusted relative risk of severe bronchopulmonary dysplasia increased progressively from 1.72 (95% confidence interval, 1.55-1.90) at the 2nd decile to 20.40 (95% confidence interval, 12.88-32.32) at the 10th decile. Similar risk gradients were observed for time in hypoxemia. Significant differences in the rates of hypoxemia between infants with and without severe bronchopulmonary dysplasia emerged within the first week after birth. Conclusions: Prolonged intermittent hypoxemia beginning in the first week after birth was associated with an increased risk of developing severe bronchopulmonary dysplasia among extremely preterm infants. Clinical trial registered with www.isrctn.com (ISRCTN62491227) and www.clinicaltrials.gov (NCT00637169).

Early Gut Microbiota Colonisation of Premature Infants Fed with Breastmilk or Formula with or without Probiotics: A Cohort Study

Premature infants have a fragile ecology of the gut microbiota, which is associated with many health problems and may be influenced by formula versus breast feeding. The present study investigated differences in the process of gut microbiota colonisation in preterm infants fed with breastmilk or formula with or without probiotics before 12 weeks. This cohort study recruited 138 premature infants; 31 in the breastmilk (BM) group, 59 in the probiotics formula (PF) group and 48 in the non-probiotics formula (NPF) group, according to the feeding practice they received at birth. Gut bacterial composition was identified with 16S rRNA gene sequencing in faecal samples collected at 1 week, 6 weeks and 12 weeks after birth. The alpha diversity was higher in the PF group compared to the other groups at week 1 and 6 (both p < 0.01) but showed no difference at week 12. The beta diversity of the three groups showed a trend towards similarity at the first two stages (p < 0.001 and p = 0.009, respectively) and finally showed no difference at week 12. Canonical redundancy analysis showed that feeding type could explain the difference in gut microbiota composition at week one and six (both p < 0.01). At genus level, Bifidobacterium was enriched in the PF group, while the Enterococcus and Streptococcus was enriched in the NPF group. In summary, formula with probiotics feeding after birth can affect gut microbiota colonisation and lead to a bacterial community with less potential pathogens.

The role of parental education on the relationship between gestational age and school outcomes

BACKGROUND

Individuals born preterm may experience difficulties beyond the neonatal period, such as poorer school outcomes. However, whether these outcomes are modified by family factors is less well-known.

OBJECTIVES

To investigate whether parental educational level modify the relationship of gestational age with completion of final examinations and grade point average in compulsory education.

METHODS

This nationwide register-based cohort study included singletons born in Denmark during 1995-2001. We investigated the differences in the associations between gestational age (24-44 weeks) and two school outcomes at 16 years according to parental educational level (lower (≤10 years), intermediate (11-13 years), and higher (>13 years)). Mixed-effect logistic regression and mixed-effect linear regression were used to model completion of final examination and grade point average, respectively.

RESULTS

Of the 425 101 singletons, 4.7% were born before 37 weeks. The risk of not completing final examination increased with shorter gestational age and lower parental educational level. For instance, among adolescents whose parents had a lower educational level, the risk increased from 23.9% (95% CI, 23.1, 24.6) for those born in week 40 to 36.6% (95% CI, 31.5, 42.1) for those born in week 28. For adolescents whose parents had a higher educational level, the corresponding risk increase was 5.9% (95% CI, 5.7, 6.1) to 10.5% (95% CI, 8.6, 12.8), respectively. Grade point average decreased with shorter gestational age in adolescents born before 30 weeks and with lower parental educational level. The associations between gestational age and grade point average were similar across parental educational levels. For completions of final examination, the associations with gestational age were weaker with higher parental educational level.

CONCLUSIONS

Shorter gestational age and lower parental educational level were associated with poorer school outcomes. Our findings suggest that parental educational level mitigates the adverse effects of shorter gestational age on some school outcomes.

Neurodevelopmental outcomes of infants with bronchopulmonary dysplasia

Preterm infants with bronchopulmonary dysplasia (BPD), and particularly those who develop the most severe forms of chronic lung disease during the neonatal period, are at high risk for poor developmental outcomes throughout childhood. Infants who require mechanical ventilation at 36 weeks post-menstrual age have significantly increased odds for cerebral palsy, developmental delay at 2 years, and poor academic achievement and low intelligence quotient in adolescence. Over the past several decades, many therapies and care strategies, including steroids, continuous positive airway pressure, surfactant, and other medications have been introduced into clinical practice. These approaches have changed the epidemiology of BPD in very preterm infants. However, BPD remains common and strongly associated with poor development throughout childhood. Only caffeine has been proven to reduce BPD and improve childhood developmental outcomes. In future research, it will be essential to better understand the developmental sequelae of BPD beyond school age and to test interventions to improve developmental trajectories in this population. As new management strategies for BPD are developed, it will be essential to rigorously evaluate both short-term and long-term effects before they are introduced into routine neonatal practice.

Neurodevelopmental outcome of patients with congenital gastrointestinal malformations: a systematic review and meta-analysis

AIM

Children with congenital gastrointestinal malformations may be at risk of neurodevelopmental impairment due to challenges to the developing brain, including perioperative haemodynamic changes, exposure to anaesthetics and postoperative inflammatory influences. This study aggregates existing evidence on neurodevelopmental outcome in these patients using meta-analysis.

METHOD

PubMed, Embase and Web of Science were searched for peer-reviewed articles published until October 2019. Out of the 5316 unique articles that were identified, 47 studies met the inclusion criteria and were included. Standardised mean differences (Cohen's d) between cognitive, motor and language outcome of patients with congenital gastrointestinal malformations and normative data (39 studies) or the studies' control group (8 studies) were aggregated across studies using random-effects meta-analysis. The value of (clinical) moderators was studied using meta-regression and diagnostic subgroups were compared.

RESULTS

The 47 included studies encompassed 62 cohorts, representing 2312 patients. Children with congenital gastrointestinal malformations had small-sized cognitive impairment (d=-0.435, p<0.001; 95% CI -0.567 to -0.302), medium-sized motor impairment (d=-0.610, p<0.001; 95% CI -0.769 to -0.451) and medium-sized language impairment (d=-0.670, p<0.001; 95% CI -0.914 to -0.425). Patients with short bowel syndrome had worse motor outcome. Neurodevelopmental outcome was related to the number of surgeries and length of total hospital stay, while no relations were observed with gestational age, birth weight, age and sex.

INTERPRETATION

This study shows that children with congenital gastrointestinal malformations exhibit impairments in neurodevelopmental outcome, highlighting the need for routine screening of neurodevelopment during follow-up.

Social Functioning in Adults Born Very Preterm: Individual Participant Meta-analysis

CONTEXT

There is a lack of research on individual perceptions of social experiences and social relationships among very preterm (VP) adults compared with term-born peers.

OBJECTIVE

To investigate self-perceived social functioning in adults born VP (<32 weeks' gestation) and/or with very low birth weight (VLBW) (<1500g) compared with term-born adults (≥37 weeks' gestation) using an individual participant data (IPD) meta-analysis.

DATA SOURCES

Two international consortia: Research on European Children and Adults born Preterm and Adults Born Preterm International Collaboration.

STUDY SELECTION

Cohorts with outcomes assessed by using the Adult Self-Report Adaptive Functioning scales (friends, spouse/partner, family, job, and education) in both groups.

DATA EXTRACTION

IPD from 5 eligible cohorts were collected. Raw-sum scores for each scale were standardized as z scores by using mean and SD of controls for each cohort. Pooled effect size was measured by difference (Δ) in means between groups.

RESULTS

One-stage analyses (1285 participants) revealed significantly lower scores for relationships with friends in VP/VLBW adults compared with controls (Δ -0.37, 95% confidence interval [CI]: -0.61 to -0.13). Differences were similar after adjusting for sex, age, and socioeconomic status (Δ -0.39, 95% CI: -0.63 to -0.15) and after excluding participants with neurosensory impairment (Δ -0.34, 95% CI: -0.61 to -0.07). No significant differences were found in other domains.

LIMITATIONS

Generalizability of research findings to VP survivors born in recent decades.

CONCLUSIONS

VP/VLBW adults scored their relationship with friends lower but perceived their family and partner relationships, as well as work and educational experiences, as comparable to those of controls.

Neuropsychological Development and New Criteria for Extrauterine Growth Restriction in Very Low-Birth-Weight Children

Background: Controversy between short-term neonatal growth of very low birth-weight preterm (VLBW) and neurodevelopment may be affected by criteria changes of extrauterine growth restriction (EUGR). Objective: to determine if new EUGR criteria imply modifications in the relationship between old criteria and results of neuropsychological tests in preterm children. Patients and methods: 87 VLBW at 5–7 years of age were studied. Neuropsychological assessment included RIST test (Reynolds Intellectual Sctreening Test) and NEPSY-II (NE neuro, PSY psycolgy assessment) tests. The relationships between these tests and the different growth parameters were analyzed. Results: RIST index was correlated with z-score Fenton’s weight (p = 0.004) and length (p = 0.003) and with z-score IGW-21’s (INTERGRWTH-21 Project) weight (p = 0.004) and length (p = 0.003) at neonatal discharge, but not with z-score difference between birth and neonatal discharge in weight, length, and HC for both. We did not find a statistically significant correlation between Fenton or IGW-21 z-scores and scalar data of NEPSY-II subtasks. Conclusion: In our series, neonatal growth influence on neuropsychological tests at the beginning of primary school does not seem robust, except for RIST test. New EUGR criteria do not improve the predictive ability of the old ones.

Aberrant Claustrum Microstructure in Humans after Premature Birth

Several observations suggest an impact of prematurity on the claustrum. First, the claustrum's development appears to depend on transient subplate neurons of intra-uterine brain development, which are affected by prematurity. Second, the claustrum is the most densely connected region of the mammalian forebrain relative to its volume; due to its effect on pre-oligodendrocytes, prematurity impacts white matter connections and thereby the development of sources and targets of such connections, potentially including the claustrum. Third, due to its high connection degree, the claustrum contributes to general cognitive functioning (e.g., selective attention and task switching/maintaining); general cognitive functioning, however, is at risk in prematurity. Thus, we hypothesized altered claustrum structure after premature birth, with these alterations being associated with impaired general cognitive performance in premature born persons. Using T1-weighted and diffusion-weighted magnetic resonance imaging in 70 very preterm/very low-birth-weight (VP/VLBW) born adults and 87 term-born adults, we found specifically increased mean diffusivity in the claustrum of VP/VLBW adults, associated both with low birth weight and at-trend with reduced IQ. This result demonstrates altered claustrum microstructure after premature birth. Data suggest aberrant claustrum development, which is potentially related with aberrant subplate neuron and forebrain connection development of prematurity.

A very preterm infant born to mother of mirror syndrome secondary to fetomaternal hemorrhage: a case report

Background

Mirror syndrome (MS) is defined as maternal edema with fetal hydrops and placental edema with different etiologies, such as rhesus isoimmunization and twin-twin transfusion syndrome. Herein, we showcased a unique MS case secondary to fetomaternal hemorrhage (FMH).

Case presentation

A 32-year-old gravida 2 para 0 woman diagnosed with fetal hydrops was admitted to our hospital. Maternal laboratory tests revealed anemia, slightly increased creatinine and uric acid levels, hypoproteinemia, and significantly increased alpha-fetoprotein and hemoglobin-F levels. Therefore, FMH was diagnosed initially. Two days after admission, the woman had unexpectedly progressive anasarca and started to feel chest distress, palpitations, lethargy, and oliguria, and MS was suspected. An emergency cesarean section was performed to terminate the pregnancy. The maternal clinical symptoms and laboratory tests rapidly improved after delivery. A very preterm infant with a 2080-g birthweight at 31 weeks gestation survived after emergency cesarean section, active resuscitation, emergency blood transfusion, abdominocentesis, and advanced life support.

Conclusions

FMH could develop into MS, providing new insights into the etiology of MS. Once MS is diagnosed, emergency cesarean section might be an alternative treatment. The very preterm infant survived with a favorable long-term outcome, and a well-trained perinatal work team is needed for such cases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04179-5.

Cognitive and Behavioral Outcomes of School-aged Children Born Extremely Preterm: a Korean Single-center Study with Long-term Follow-up

BACKGROUND

School-aged children born very preterm have been suggested to have worse cognitive and behavioral outcomes than children born full-term. Executive function (EF) is a higher level of cognitive function related to academic achievement. The present study aimed to evaluate the cognitive (including EF) and behavioral outcomes of Korean children born extremely preterm (EP) and to analyze any biological or socioeconomic risk factors for poor cognitive outcomes in this population.

METHODS

A total of 71 infants weighing < 1,000 g at birth or born before 30 weeks of gestation (EP group) who were admitted to the neonatal intensive care unit from 2008 to 2009 were included in this study and compared with 40 term-birth controls. The Korean Wechsler Intelligence Scale for Children-Fourth Edition, Advanced Test of Attention (ATA), Stroop test, Children's Color Trails Test (CCTT), and Wisconsin Card Sorting Test (WCST) were used. Additionally, the Korean Child Behavior Checklist (K-CBCL) and Korean ADHD Rating Scale (K-ARS) were completed. Perinatal and demographic data were collected and analyzed.

RESULTS

The mean full-scale intelligence quotient (FSIQ) score in the EP group was significantly lower than that of the term control group (89.1 ± 18.3 vs. 107.1 ± 12.7; P < 0.001). In the EP group, 26 (37%) children had an FSIQ score below 85, compared to only one child (3%) in the control group. Furthermore, the EP group showed significantly worse EF test results (ATA, Stroop test, CCTT, WCST). Except for the higher social immaturity subscore in the EP group, the K-CBCL and K-ARS scores were not different between the two groups. EP children who received laser treatment for retinopathy of prematurity (ROP) had an 8.8-fold increased risk of a low FSIQ score, and a 1-point increase in the discharge weight Z-score decreased the risk of a low FSIQ score by approximately half in this EP cohort.

CONCLUSION

This is the first Korean study to investigate the cognitive and behavioral outcomes of school-aged children born EP. In the study cohort, EP children exhibited significantly lower FSIQ scores and EF than their full-term peers, and 37% of them had cognitive problems. Nonetheless, except for social immaturity, the behavioral problems were not different in EP children. Severe ROP and low discharge weight Z-score were identified as independent risk factors for low FSIQ score after adjusting for birth weight.

Optimizing respiratory management in preterm infants: a review of adjuvant pharmacotherapies

Adjuvant respiratory therapies in preterm neonates aim to reduce long-term morbidities and mortality. Commonly utilized therapies include caffeine, systemic glucocorticosteroids, inhaled steroids, inhaled bronchodilators, and diuretics. This review discusses the available literature that supports some of these practices and points out where clinical practices are not corroborated by evidence. Therapies with no proven clinical benefit must be weighed against potential adverse effects.

White matter alterations and cognitive outcomes in children born very low birth weight

BACKGROUND

Very low birth weight (VLBW) infants are at risk for disrupted white matter maturation, yet little is known about the contributing factors, particularly at preschool-age when cognitive difficulties begin to emerge. We examined white matter microstructure in five-year-old VLBW and full-term (FT) children, and its association with cognitive outcomes and birth weight.

METHODS

Multi-shell diffusion and MR images were obtained for 41 VLBW (mean birth weight: 1028.6 ± 256.8 g) and 26 FT (3295.4 ± 493.9 g) children. Fractional anisotropy (FA), radial diffusivity (RD), neurite orientation dispersion index (ODI) and density index (NDI) were estimated using diffusion tensor and neurite orientation dispersion and density imaging models. Between-group analyses used a general linear model with group and sex as explanatory variables. Within-group associations between white matter microstructure, cognitive outcomes and birth weight were also investigated.

RESULTS

VLBW compared to FT children showed lower FA and NDI across widespread white matter regions. Smaller clusters of atypical ODI were also found in VLBW children. Within-group analyses in FT children revealed that lower RD and higher NDI were associated with vocabulary acquisition and working memory. In VLBW children, higher FA and NDI, and lower RD and ODI, were associated with improved processing speed. In both groups, FA was positively associated with birth weight.

CONCLUSIONS

Our findings demonstrate white matter alterations in young VLBW children, including widespread reductions in axon density that may reflect sustained myelination disruptions. The associations with cognitive outcomes may also highlight which of the VLBW children are at higher risk for later cognitive difficulties.