Usefulness of the Korean Developmental Screening Test for infants and children for the evaluation of developmental delay in Korean infants and children: a single-center study

Impact of COVID-19 pandemic on neurodevelopmental outcome in very low birth weight infants: a nationwide cohort study

Introduction

Children who have experienced the coronavirus disease 2019 (COVID-19) pandemic are at an increased risk of adverse neurologic developmental outcomes. Limited data exist on the environmental influences of during the COVID-19 pandemic on preterm infant development. This study aimed to investigate whether COVID-19 exposure affects the neurodevelopmental outcomes in preterm children up to 3 years of age.

Methods

This prospective cohort study included all very low birth weight (VLBW) infants from the Korean Neonatal Network who had undergone a neurodevelopmental assessment between January 2015, and May 2022. The neurodevelopmental outcomes along with the scores on the Bayley Scales of Infant and Toddler Development (BSID) and the Korean Developmental Screening Test for Infants and Children of pediatric patients aged 18-24 and 33-39 months who were exposed to COVID-19 were compared with those of VLBW children born and tested before the pandemic.

Results

The cohort included 1,683 VLBW infants. The pandemic group had significantly lower language scores on the BSID-III at ages 18-24 months (p = 0.021) and 33-39 months (p = 0.023) than the pre-pandemic group after adjusting for gestational age, morbidity, and environmental factors. At 2nd follow-up period, the pandemic group showed significantly lower scores in the cognitive (p = 0.026) domains with a mean difference of 7 points and had a significantly higher percentage of ≤-1SD in the gross motor domain (p < 0.001) compared with the pre-pandemic group.

Conclusion

Preterm children who experienced the COVID-19 pandemic are at higher risk of abnormal neurodevelopmental outcomes in the first 3 years of life than preterm infants born before the COVID-19 pandemic.

Long-term impact of late pulmonary hypertension requiring medication in extremely preterm infants with severe bronchopulmonary dysplasia

This study investigated whether late pulmonary hypertension (LPH) independently increases the risk of long-term mortality or neurodevelopmental delay (NDD) in extremely preterm infants (EPIs) with severe bronchopulmonary dysplasia (BPD). Using prospectively collected data from the Korean Neonatal Network, we included EPIs with severe BPD born at 22-27 weeks' gestation between 2013 and 2021. EPIs having severe BPD with LPH (LPH, n = 124) were matched 1:3 with those without pulmonary hypertension (PH) as controls (CON, n = 372), via propensity score matching. LPH was defined as PH with the initiation of medication after 36 weeks' corrected age (CA). Long-term mortality after 36 weeks' CA or NDD at 18-24 months' CA was analyzed. NDD was assessed using composite scores based on various neurodevelopmental assessment modalities. LPH had significantly higher long-term mortality or NDD (45.2% vs. 23.1%, P < 0.001), mortality (24.2% vs. 4.84%, P < 0.001), and NDD (68.4% vs. 37.8%, P = 0.001), respectively than CON, even after adjusting for different demographic factors. Multivariable regression demonstrated that LPH independently increased the risk of mortality or NDD (adjusted odds ratio, 1.95; 95% confidence intervals, 1.17-3.25). When LPH occurs in EPIs with severe BPD, special monitoring and meticulous care for long-term survival and neurodevelopment are continuously needed.

Diagnosis and Assessment of Autism Spectrum Disorder in South Korea

Autism spectrum disorder (ASD) is diagnosed by the clinical decision of a trained professional based on the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition or International Classification of Diseases 11th Revision diagnostic criteria. To obtain information for diagnostic formulation, professionals should explore detailed developmental history, and can use structured or semi-structured assessment tools to observe interaction between the child and parents or strangers. Diagnostic assessment should include a profile of the strength and weaknesses of the individual and should be conducted using an optimal approach by a multidisciplinary team with appropriate techniques and experience. Assessment of language, cognitive, neuropsychological, and adaptive functioning should be conducted in ASD individuals prior to establishing an individualized treatment plan. Genetic testing, brain magnetic resonance imaging or electroencephalogram testing can be considered for identification of underlying causes.

Antenatal Magnesium Sulfate Is Not Associated With Improved Long-Term Neurodevelopment and Growth in Very Low Birth Weight Infants

BACKGROUND

Though antenatal magnesium sulfate (MgSO4) is widely used for fetal neuroprotection, suspicions about the long-term neuroprotection of antenatal MgSO4 have been raised.

METHODS

We investigated short- and long-term outcomes of antenatal MgSO4 use for 468 infants weighing < 1,500 g with a gestational age of 24-31 weeks.

RESULTS

Short-term morbidities and the risk of developmental delay, hearing loss, and cerebral palsy at a corrected age of 18-24 months and 3 years of age did not decrease in the MgSO4 group (infants who were exposed to MgSO4 for any purpose) or neuroprotection group (infants who were exposed to MgSO4 for fetal neuroprotection) compared with the control group (infants who were not exposed to MgSO4). The z-scores of weight, height, and head circumference did not increase in the MgSO4 group or neuroprotection group compared with the control group.

CONCLUSION

Antenatal MgSO4 including MgSO4 for neuroprotection did not have beneficial effects on long-term neurodevelopmental and growth outcomes.

Echocardiographic assessment of brain sparing in small-for-gestational age infants and association with neonatal outcomes

Brain sparing is an adaptive phenomenon (redistribution of blood flow to the brain) observed in fetuses exposed to chronic hypoxia, who are at risk of intrauterine growth restriction. Here, we assessed the blood flow distribution during the early neonatal period (< 7 days of life) using echocardiography, and evaluated the impact of brain-sparing on postnatal course and neurodevelopmental outcomes. This retrospective study included 42 small-for-gestational age (SGA) infants [further classified into asymmetric SGA (a-SGA, n = 21) and symmetric SGA (s-SGA, n = 21) groups according to their birth head circumference percentiles], and 1: 2 matched appropriate-for-gestational age (AGA) infants (n = 84) admitted to the neonatal intensive care unit. Left ventricular (LV) stroke volume, LV cardiac output (LVCO), upper body blood flow (UBBF), and UBBF/LVCO ratio (%) were significantly higher in both a-SGA and s-SGA infants than in AGA infants. Both a-SGA and s-SGA groups consisted predominantly of infants with higher UBBF/LVCO (%). A UBBF/LVCO ≥ 58.2% (3rd interquartile range) was associated with a later need for rehabilitative therapy after discharge. In summary, brain-sparing effect may continue during the early postnatal life in SGA infants, and may be a promising marker to detect future adverse neurodevelopmental outcomes.

Impact of time to full enteral feeding on long-term neurodevelopment without mediating by postnatal growth failure in very-low-birth-weight-infants

This study aimed to determine if time to achieve full enteral feeding (TFF) directly impacted long-term neurodevelopmental delay (NDD) and whether long-term postnatal growth failure (PGF) was a mediator of this association in very-low-birth-weight (VLBW) infants. Using prospectively collected cohort data from the Korean Neonatal Network, we included eligible VLBW infants who achieved TFF at least once and classified enrolled infants into four groups using exposure severity (P1 to P4 as TFF < 16, 16-30, 31-45, and > 45 postnatal days, respectively). After adjusting for confounding variables, survival without NDD was significantly decreased in P4 infants compared with that in P2 infants. P1 infants had a lower risk of weight and height PGF than P2 infants; however, P4 infants had higher risks of height and head circumference PGF than P2 infants. Weight and height PGF were significantly associated with an increased risk of NDD. In mediation analysis, early and delayed TFF revealed direct positive and negative impacts, respectively, on the risk of NDD without mediation by PGF. TFF impacted survival without NDD, and PGF did not mediate this association in VLBW infants. Additionally, these results can be translated into evidence-based quality improvement practice.

Association Between Retinopathy of Prematurity in Very-Low-Birth-Weight Infants and Neurodevelopmental Impairment

PURPOSE

To evaluate the impact of retinopathy of prematurity (ROP) severity and the treatment of very-low-birth-weight infants (VLBWIs) on neurodevelopmental impairment in early childhood.

DESIGN

Prospective cohort study.

METHOD

This was a prospective cohort study. The data were obtained from the Korean Neonatal Network (KNN), a nationwide registry for VLBWIs. Infants who were born from 2013 to 2015 and underwent ROP evaluation at birth and neurodevelopmental examinations at corrected ages of 18 to 24 months were included in the study. Infants with a history of meningitis or severe congenital anomalies were excluded. The VLBWI patients were grouped into no ROP, no treatment-requiring ROP (non-TR-ROP), and treatment-requiring ROP (TR-ROP) groups. Neurodevelopmental impairment was defined as participants who had at least 1 developmental problem according to the Bayley Scales of Infant and Toddler Development-2nd Edition (Bayley-II; <70), Bayley Scales of Infant and Toddler Development-3rd Edition (Bayley-III; <70), and Korean Developmental Screening Test (K-DST) tests (below -1 SD), and the Korean Ages and Stages Questionnaire (K-ASQ) (below the threshold) and Gross Motor Function Classification System (GMFCS; at level 2 or above). Multivariable logistic regression analysis was performed to evaluate the association between ROP and neurodevelopmental impairment.

RESULT

Among 3132 infants, 1093 (34.9%) had ROP. Among the ROP infants, 644 were not treated for ROP (non-TR-ROP group) and 449 received ROP treatments (TR-ROP group). The patients in the TR-ROP group had an increased risk of developing neurodevelopmental problems compared to those in the no ROP group (odds ratio [OR] = 1.72, 95% CI = 1.33-2.21). The TR-ROP group had a higher risk of all 3 types of neurodevelopmental problems: mental (OR = 1.62, 95% CI = 1.25-2.09), social (OR = 1.62, 95% CI = 1.12-2.09), and motor (OR = 1.69, 95% CI = 1.31-2.18). The risk of neurodevelopmental problems in patients treated with laser therapy did not differ from that in patients treated with anti-vascular endothelial growth factor (anti-VEGF) therapy (OR = 1.17, 95% CI = 0.73-1.88).

CONCLUSION

ROP was independently associated with neurodevelopmental impairment in early childhood. The type of ROP treatment (anti-VEGF or laser treatment) did not affect neurodevelopmental impairment in patients in the TR-ROP group.

Impact of Outborn/Inborn Birth Status of Infants Born at <29 Weeks of Gestation on Neurodevelopmental Impairment: A Nationwide Cohort Study in Korea

This study designed to evaluate the short- and long-term outcomes of outborn and inborn preterm infants enhancing the regional perinatal system in South Korea. It is a prospective cohort study of the Korean neonatal network database for infants born at <29 weeks of gestation between 2013 and 2015. Of 2995 eligible infants, 312 were outborn, and 976 completed the assessment of long-term outcome at 18-24 months of corrected age. The mean gestational age was significantly younger in outborn infants than in inborn infants (p = 0.004). The mean Apgar score at 5 min was higher in inborn infants (p = 0.046). More inborn preterm infants died before discharge (p < 0.001); however, most of the other short-term outcomes occurred significantly more often in outborn infants than in inborn infants. The outborn infants had higher odds of neurodevelopmental impairment (adjusted odds ratio (aOR) 2.412, 95% confidence interval (CI) 1.585-3.670), cerebral palsy (aOR 4.460, 95% CI 2.249-8.845) and developmental impairment (aOR 2.238, 95% CI 1.469-3.408). In preterm infants, the location of birth may be a key factor influencing short- and long-term outcomes. Thus, to provide adequate care and efficiently allocate medical resources to high-risk preterm infants, nationwide regional perinatal systems need to be improved and standardized.

Altered Cerebral Curvature in Preterm Infants Is Associated with the Common Genetic Variation Related to Autism Spectrum Disorder and Lipid Metabolism

Preterm births are often associated with neurodevelopmental impairment. In the critical developmental period of the fetal brain, preterm birth disrupts cortical maturation. Notably, preterm birth leads to alterations in the fronto-striatal and temporal lobes and the limbic region. Recent advances in MRI acquisition and analysis methods have revealed an integrated approach to the genetic influence on brain structure. Based on imaging studies, we hypothesized that the altered cortical structure observed after preterm birth is associated with common genetic variations. We found that the presence of the minor allele at rs1042778 in OXTR was associated with reduced curvature in the right medial orbitofrontal gyrus (p < 0.001). The presence of the minor allele at rs174576 in FADS2 (p < 0.001) or rs740603 in COMT (p < 0.001) was related to reduced curvature in the left posterior cingulate gyrus. This study provides biological insight into altered cortical curvature at term-equivalent age, suggesting that the common genetic variations related to autism spectrum disorder (ASD) and lipid metabolism may mediate vulnerability to early cortical dysmaturation in preterm infants.

Definitions of bronchopulmonary dysplasia and long-term outcomes of extremely preterm infants in Korean Neonatal Network

New definitions for bronchopulmonary dysplasia (BPD) have recently been suggested, and an accurate diagnosis, including severity classification with proper definition, is crucial to identify high-risk infants for appropriate interventions. To determine whether recently suggested BPD definitions can better predict long-term outcomes of BPD in extremely preterm infants (EPIs) than the original BPD definition, BPD was classified with severity 1, 2, and 3 using three different definitions: definition A (original), National Institute of Child Health and Human Development (NICHD) definition in 2001; definition B, the modified NICHD 2016 definition (graded by the oxygen concentration and the respiratory support at 36 weeks’ postmenstrual age [PMA]); and definition C, the modified Jensen 2019 definition (graded by the respiratory support at 36 weeks’ PMA). We evaluated 1050 EPIs using a national cohort. Whereas EPIs with grade 2 or 3 BPD as per definition A did not show any increase in the risk, EPIs with BPD diagnosed by definition B and C showed significantly increased risk for poor outcomes, such as respiratory mortality and morbidities, neurodevelopmental delay, and growth restriction at 18–24 months of corrected age. The recently suggested definition and severity grading better reflects long-term childhood morbidities than the original definition in EPIs.

Impact of the definition of bronchopulmonary dysplasia on neurodevelopmental outcomes

Understanding the short and long-term pulmonary and neurologic outcomes of neonates with bronchopulmonary dysplasia (BPD) is important in neonatal care for low-birth-weight infants. Different criteria for BPD may have different associations with long-term outcomes. Currently, two criteria for diagnosing BPD have been proposed by the NIH (2001) and NRN (2019) for preterm infants at a postmenstrual age (PMA) of 36 weeks. We investigated which BPD definition best predicts long-term outcomes. Korean nationwide data for preterm infants born between 24+0 and < 32+0 weeks gestation from January 2013 to December 2015 were collected. For long-term outcomes, severity based on the NRN criteria was significantly related to neurodevelopmental impairment (NDI) in a univariate analysis after other risk factors were controlled. For the admission rate for respiratory disorder, grade 3 BPD of the NRN criteria had the highest specificity (96%), negative predictive value (86%), and accuracy (83%). For predicting NDI at the 18-24 month follow-up, grade 3 BPD of the NRN criteria had the best specificity (98%), positive (64%) and negative (79%) predictive values, and accuracy (78%) while NIH severe BPD had the highest sensitivity (60%). The NRN definition was more strongly associated with poor 2-year developmental outcomes. BPD diagnosed by NRN definitions might better identify infants at high risk for NDI.

Central precocious puberty may be a manifestation of endocrine dysfunction in pediatric patients with mitochondrial disease

We retrospectively reviewed the data of 140 female pediatric patients with rare mitochondrial diseases (MDs) confirmed using muscle biopsy. We evaluated patients who were diagnosed with central precocious puberty (PP) with early pubertal development to determine whether PP is a clinical manifestation of MDs. We also examined the clinical, auxiological, laboratory, and radiological parameters after 1 year of gonadotropin-releasing hormone treatment for central PP. Among the 140 girls with MDs, 29 had early pubertal development and underwent endocrine evaluation. Ten (7.1%) patients were diagnosed with central PP; the prevalence of central PP was higher than was that previously thought. Patients with central PP exhibited bone age advancement over 1 year and increased sex hormone levels despite their young age at diagnosis. Serum estradiol levels were significantly higher in younger patients than in older patients (P = 0.004). Patients with central PP treated with gonadotropin-releasing hormone had favorable outcomes, and their pubertal development was suppressed for 1 year.Conclusion: Central PP may be a manifestation of endocrine dysfunction in young girls with MDs. What is Known: • The general characteristics of mitochondrial diseases include developmental delays and retarded growth. • Precocious puberty has rarely been suggested as a clinical manifestation of mitochondrial diseases. What is New: • Among the 140 girls with mitochondrial diseases, 10 (7.1%) were diagnosed with central precocious puberty. • Serum estradiol levels were significantly higher in younger patients than in older patients.

Relationship between Clinical Parameters and Chromosomal Microarray Data in Infants with Developmental Delay

Chromosomal microarray (CMA) is considered a first-tier test for genetic analysis as it can be used to examine gene copy number variations (CNVs) throughout the entire genome, with enhanced sensitivity for detecting submicroscopic deletions and duplications. However, its cost can represent a heavy burden. Moreover, the diagnostic yield of CMA in infants with developmental delay (DD) was reported to be less than 10%. Therefore, we aimed to investigate the relationship between CMA results and clinical features and risk factors of DD. The study included 59 infants with DD who were recruited between August 2019 and February 2020 during a visit to the outpatient clinic of a rehabilitation department. We reviewed the clinical records of the infants regarding gender, age, body weight at birth, delivery method, brain imaging data, perinatal history, and parent-related clinical parameters, such as mother and father age at birth. The infants were categorized according to CMA results, and differences in clinical parameters were evaluated. Except for brain anomalies, there was no statistically significant differences between infants who had pathogenic and variants of unknown significance (VOUS)-likely pathogenic CNVs groups compared with those within the VOUS-likely no sub-classification, VOUS-likely benign, benign, and normal CNVs groups. The incidence of brain anomalies was significantly higher within infants with pathogenic and VOUS-likely pathogenic CNVs groups (p < 0.05). Our study suggests that infants with DD who present dysmorphism or brain anomaly may benefit from early CMA analysis, for adequate diagnosis and timely treatment. Further studies are warranted to confirm the relationship between DD clinical parameters and CMA results.

Enlarged subarachnoid space on cranial ultrasound in preterm infants: Neurodevelopmental implication

The role of enlarged subarachnoid space (ESS) in preterm infants has not been described in concrete. We aimed to evaluate whether ESS should be considered a risk factor potentially associated with adverse neurodevelopmental outcomes in prematurity. Electronic medical records of 197 preterm infants (median 32.1 weeks' gestation) including cranial ultrasound (cUS) images, head circumferences, and Korean Developmental Screening Tests for Infants and Children (K-DST) results at 18–24 months corrected age were reviewed. The clinical characteristics and K-DST results were compared in infants with and without ESS (sinocortical width > 3.5 mm). A multivariable logistic regression analysis was performed to identify potential risk factors associated with positive K-DST results. At a median corrected age of 39.0 weeks, 81/197 (41.1%) infants presented ESS. A significantly greater percent of infants in the ESS group screened positive on the K-DST than in the no ESS group (27.2% vs 12.1%, p = 0.007). Within the ESS group, micro-/macrocephaly at term-equivalent age was not different with regard to the K-DST results. From the multivariable logistic regression analysis, gestational age (p = 0.016, OR = 0.855, 95% CI = 0.753–0.971) and ESS (p = 0.019, OR = 1.310, 95% CI = 1.046–1.641) were two significant risk factors associated with positive K-DST results. ESS identified on cUS at term-equivalent age in preterm infants is associated with possible developmental delays. Macrocephaly at term-equivalent age does not guarantee a benign prognosis. Future studies are required to verify ESS as a potential marker for neurodevelopmental delay in preterm infants.

Clinical Usefulness of the Korean Developmental Screening Test (K-DST) for Developmental Delays

Objective

To evaluate the clinical usefulness of the Korean Developmental Screening Test (K-DST) via comparison with Korean Ages and Stages Questionnaire (K-ASQ) for the diagnosis of developmental delay in pediatric patients.

Methods

The K-DST and K-ASQ were used to screen pediatric patients who visited the hospital for evaluation and diagnosis of delayed development. Korean Bayley Scales of Infant Development-II (K-BSID-II) or Korean Wechsler Preschool and Primary Scale of Intelligence III (K-WPPSI-III) were used for the standardized assessment. Moreover, the final clinical diagnosis was confirmed by three expert physicians (rehabilitation doctor, psychiatrist, and neurologist). The sensitivity and specificity of each screening tool for the final diagnosis were investigated and correlated with standardized assessments.

Results

A total of 145 pediatric consultations were conducted, which included 123 developmental disorders (40 autism spectrum disorders, 46 global developmental delay/intellectual disability, and 37 developmental language disorders) and another 22 that were not associated with any such disorders. The sensitivity and specificity of K-DST based on the final clinical diagnosis were 82.9% and 90.9%, respectively, which were not significantly different from that of K-ASQ (83.7% and 77.3%). Both K-DST and K-ASQ showed good correlation with K-BSID-II and K-WPPSI-III. No significant difference was found between the K-DST and K-ASQ measures.

Conclusion

K-DST is an excellent screening tool and is expected to replace K-ASQ with high validity.

Validity of the Korean Developmental Screening Test for very-low-birth-weight infants

PURPOSE

The importance of the neurodevelopmental outcomes of very-low-birth-weight (VLBW) infants has been emphasized as their mortality rate has markedly improved. This study aimed to assess the validity of the Korean Developmental Screening Test (K-DST), a developmental screening tool approved by the Korean Society of Pediatrics, for the timely diagnosis of neurodevelopmental delay in VLBW infants.

METHODS

Subjects included VLBW infants enrolled in the Korean Neonatal Network database between January 2012 and December 2014. The collected data were analyzed for sensitivity, specificity, positive predictive value, and negative predictive value (NPV) in the K-DST compared to those in the Bayley Scales of Infant Development-II for VLBW infants.

RESULTS

A total of 173 patients were enrolled. Their mean gestational age and mean birth weight were 27.5±2.8 weeks and 980.5±272.1 g, respectively. The frequency of failed psychomotor developmental index (PDI) <85 was similar to that in at least one domain of K-DST <1 standard deviation. Failure in more than one K-DST domain compared with a mental developmental index (MDI) <85 showed a sensitivity and NPV of 73.2% and 75.0%, respectively. Failure in more than one K-DST domain compared with PDI <85 showed a sensitivity and NPV of 60.3% and 71.6%, respectively. Each K-DST domain had a stronger correlation with predicting a failing MDI <85 than a failing PDI <85 (P<0.05).

CONCLUSION

K-DST could be a useful screening tool for predicting mental developmental delay in VLBW infants and referring them for neurodevelopmental assessments.