Background: The relationship between early life factors and childhood pulmonary function and structure in preterm infants remains unclear.Purpose: This study investigated the impact of bronchopulmonary dysplasia (BPD) and perinatal factors on childhood pulmonary function and structure. Methods: This longitudinal cohort study included preterm participants aged ≥5 years born between 2005 and 2015. The children were grouped by BPD severity according to National Institutes of Health criteria. Pulmonary function tests (PFTs) were performed using spirometry. Chest computed tomography (CT) scans were obtained and scored for hyperaeration or parenchymal lesions. PFT results and chest CT scores were analyzed with perinatal factors. Results: A total 150 children (66 females) aged 7.7 years (6.4–9.9 years) were categorized into non/mild BPD (n=68), moderate BPD (n=39), and severe BPD (n=43) groups. The median z score for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced midexpiratory flow (FEF25%–75%) were significantly lower in the severe versus non/mild BPD group (-1.24 vs. -0.18, -0.22 vs. 0.41, -1.80 vs. -1.12, and -1.88 vs. -1.00, respectively; all P<0.05). The median z scores of FEV1, FEV1/ FVC, and FEF25%–75% among asymptomatic patients were also significantly lower in the severe versus non/mild BPD group (-0.82 vs. 0.09, -1.68 vs. -0.87, -1.59 vs. -0.61, respectively; all P<0.05). The severe BPD group had a higher median (range) CT score than the non/mild BPD group (6 [0–12] vs. 1 [0–10], P<0.001). Prenatal oligohydramnios was strongly associated with both low pulmonary function (FEV1/FVCConclusion School-aged children with severe BPD showed airflow limitations and structural abnormalities despite no subjective respiratory symptoms. These results suggest that patients with a history of prenatal oligohydramnios or prolonged mechanical ventilation require extended follow-up.

Background: Very low birth weight infants (VLBWIs) continue to face high mortality risk influenced by the care quality of neonatal intensive care units (NICUs). Under-standing the impact of workload and regional differences on these rates is crucial for improving outcomes.Purpose: This study aimed to assess how the structural and staffing attributes of NICUs influence the mortality rates of VLBWIs, emphasizing the significance of the availability of medical personnel and the regional distribution of care facilities. Methods: Data from 69 Korean NICUs collected by the Korean Neonatal Network between January 2015 and December 2016 were retrospectively analyzed. The NICUs were classified by various parameters: capacity (small, medium, large), nurse-to-bed ratio (1–4), and regional location (A, B, C). Pediatrician staffing was also analyzed and NICUs categorized by beds per pediatrician into low (≤10), medium (11–15), and high (≥16). The NICUs were classified by mortality rates into high-performance (1st and 2nd quartiles) and low-performance (3rd and 4th quartiles). Demographic, perinatal, and neonatal outcomes were analyzed using multivariate logistic regression to explore the association between NICU characteristics and mortality rates. Results: This study included 4,745 VLBWIs (mean gestational age, 28.4 weeks; mean birth weight, 1,088 g; 55.4% male) and found significant variations in survival rates across NICUs linked to performance and staffing levels. High-performing NICUs, often with lower bed-to-staff ratios and advanced care levels, had higher survival rates. Notably, NICUs with 2 rather than 1 neonatologist were associated with reduced mortality rates. The study also underscored regional disparities, with NICUs in certain areas showing less favorable survival rates. Conclusion Adequate NICU staffing and proper facility location are key to lowering the number of VLBWI deaths. Enhancing staffing and regional healthcare equity is crucial for improving the survival of this population.

Background: The relationship between early life factors and childhood pulmonary function and structure in preterm infants remains unclear.Purpose: This study investigated the impact of bronchopulmonary dysplasia (BPD) and perinatal factors on childhood pulmonary function and structure. Methods: This longitudinal cohort study included preterm participants aged ≥5 years born between 2005 and 2015. The children were grouped by BPD severity according to National Institutes of Health criteria. Pulmonary function tests (PFTs) were performed using spirometry. Chest computed tomography (CT) scans were obtained and scored for hyperaeration or parenchymal lesions. PFT results and chest CT scores were analyzed with perinatal factors. Results: A total 150 children (66 females) aged 7.7 years (6.4–9.9 years) were categorized into non/mild BPD (n=68), moderate BPD (n=39), and severe BPD (n=43) groups. The median z score for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced midexpiratory flow (FEF25%–75%) were significantly lower in the severe versus non/mild BPD group (-1.24 vs. -0.18, -0.22 vs. 0.41, -1.80 vs. -1.12, and -1.88 vs. -1.00, respectively; all P<0.05). The median z scores of FEV1, FEV1/ FVC, and FEF25%–75% among asymptomatic patients were also significantly lower in the severe versus non/mild BPD group (-0.82 vs. 0.09, -1.68 vs. -0.87, -1.59 vs. -0.61, respectively; all P<0.05). The severe BPD group had a higher median (range) CT score than the non/mild BPD group (6 [0–12] vs. 1 [0–10], P<0.001). Prenatal oligohydramnios was strongly associated with both low pulmonary function (FEV1/FVCConclusion School-aged children with severe BPD showed airflow limitations and structural abnormalities despite no subjective respiratory symptoms. These results suggest that patients with a history of prenatal oligohydramnios or prolonged mechanical ventilation require extended follow-up.

Background: Very low birth weight infants (VLBWIs) continue to face high mortality risk influenced by the care quality of neonatal intensive care units (NICUs). Under-standing the impact of workload and regional differences on these rates is crucial for improving outcomes.Purpose: This study aimed to assess how the structural and staffing attributes of NICUs influence the mortality rates of VLBWIs, emphasizing the significance of the availability of medical personnel and the regional distribution of care facilities. Methods: Data from 69 Korean NICUs collected by the Korean Neonatal Network between January 2015 and December 2016 were retrospectively analyzed. The NICUs were classified by various parameters: capacity (small, medium, large), nurse-to-bed ratio (1–4), and regional location (A, B, C). Pediatrician staffing was also analyzed and NICUs categorized by beds per pediatrician into low (≤10), medium (11–15), and high (≥16). The NICUs were classified by mortality rates into high-performance (1st and 2nd quartiles) and low-performance (3rd and 4th quartiles). Demographic, perinatal, and neonatal outcomes were analyzed using multivariate logistic regression to explore the association between NICU characteristics and mortality rates. Results: This study included 4,745 VLBWIs (mean gestational age, 28.4 weeks; mean birth weight, 1,088 g; 55.4% male) and found significant variations in survival rates across NICUs linked to performance and staffing levels. High-performing NICUs, often with lower bed-to-staff ratios and advanced care levels, had higher survival rates. Notably, NICUs with 2 rather than 1 neonatologist were associated with reduced mortality rates. The study also underscored regional disparities, with NICUs in certain areas showing less favorable survival rates. Conclusion Adequate NICU staffing and proper facility location are key to lowering the number of VLBWI deaths. Enhancing staffing and regional healthcare equity is crucial for improving the survival of this population.

Background: The relationship between early life factors and childhood pulmonary function and structure in preterm infants remains unclear.Purpose: This study investigated the impact of bronchopulmonary dysplasia (BPD) and perinatal factors on childhood pulmonary function and structure. Methods: This longitudinal cohort study included preterm participants aged ≥5 years born between 2005 and 2015. The children were grouped by BPD severity according to National Institutes of Health criteria. Pulmonary function tests (PFTs) were performed using spirometry. Chest computed tomography (CT) scans were obtained and scored for hyperaeration or parenchymal lesions. PFT results and chest CT scores were analyzed with perinatal factors. Results: A total 150 children (66 females) aged 7.7 years (6.4–9.9 years) were categorized into non/mild BPD (n=68), moderate BPD (n=39), and severe BPD (n=43) groups. The median z score for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced midexpiratory flow (FEF25%–75%) were significantly lower in the severe versus non/mild BPD group (-1.24 vs. -0.18, -0.22 vs. 0.41, -1.80 vs. -1.12, and -1.88 vs. -1.00, respectively; all P<0.05). The median z scores of FEV1, FEV1/ FVC, and FEF25%–75% among asymptomatic patients were also significantly lower in the severe versus non/mild BPD group (-0.82 vs. 0.09, -1.68 vs. -0.87, -1.59 vs. -0.61, respectively; all P<0.05). The severe BPD group had a higher median (range) CT score than the non/mild BPD group (6 [0–12] vs. 1 [0–10], P<0.001). Prenatal oligohydramnios was strongly associated with both low pulmonary function (FEV1/FVCConclusion School-aged children with severe BPD showed airflow limitations and structural abnormalities despite no subjective respiratory symptoms. These results suggest that patients with a history of prenatal oligohydramnios or prolonged mechanical ventilation require extended follow-up.

Background: Very low birth weight infants (VLBWIs) continue to face high mortality risk influenced by the care quality of neonatal intensive care units (NICUs). Under-standing the impact of workload and regional differences on these rates is crucial for improving outcomes.Purpose: This study aimed to assess how the structural and staffing attributes of NICUs influence the mortality rates of VLBWIs, emphasizing the significance of the availability of medical personnel and the regional distribution of care facilities. Methods: Data from 69 Korean NICUs collected by the Korean Neonatal Network between January 2015 and December 2016 were retrospectively analyzed. The NICUs were classified by various parameters: capacity (small, medium, large), nurse-to-bed ratio (1–4), and regional location (A, B, C). Pediatrician staffing was also analyzed and NICUs categorized by beds per pediatrician into low (≤10), medium (11–15), and high (≥16). The NICUs were classified by mortality rates into high-performance (1st and 2nd quartiles) and low-performance (3rd and 4th quartiles). Demographic, perinatal, and neonatal outcomes were analyzed using multivariate logistic regression to explore the association between NICU characteristics and mortality rates. Results: This study included 4,745 VLBWIs (mean gestational age, 28.4 weeks; mean birth weight, 1,088 g; 55.4% male) and found significant variations in survival rates across NICUs linked to performance and staffing levels. High-performing NICUs, often with lower bed-to-staff ratios and advanced care levels, had higher survival rates. Notably, NICUs with 2 rather than 1 neonatologist were associated with reduced mortality rates. The study also underscored regional disparities, with NICUs in certain areas showing less favorable survival rates. Conclusion Adequate NICU staffing and proper facility location are key to lowering the number of VLBWI deaths. Enhancing staffing and regional healthcare equity is crucial for improving the survival of this population.

Background: The relationship between early life factors and childhood pulmonary function and structure in preterm infants remains unclear.Purpose: This study investigated the impact of bronchopulmonary dysplasia (BPD) and perinatal factors on childhood pulmonary function and structure. Methods: This longitudinal cohort study included preterm participants aged ≥5 years born between 2005 and 2015. The children were grouped by BPD severity according to National Institutes of Health criteria. Pulmonary function tests (PFTs) were performed using spirometry. Chest computed tomography (CT) scans were obtained and scored for hyperaeration or parenchymal lesions. PFT results and chest CT scores were analyzed with perinatal factors. Results: A total 150 children (66 females) aged 7.7 years (6.4–9.9 years) were categorized into non/mild BPD (n=68), moderate BPD (n=39), and severe BPD (n=43) groups. The median z score for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced midexpiratory flow (FEF25%–75%) were significantly lower in the severe versus non/mild BPD group (-1.24 vs. -0.18, -0.22 vs. 0.41, -1.80 vs. -1.12, and -1.88 vs. -1.00, respectively; all P<0.05). The median z scores of FEV1, FEV1/ FVC, and FEF25%–75% among asymptomatic patients were also significantly lower in the severe versus non/mild BPD group (-0.82 vs. 0.09, -1.68 vs. -0.87, -1.59 vs. -0.61, respectively; all P<0.05). The severe BPD group had a higher median (range) CT score than the non/mild BPD group (6 [0–12] vs. 1 [0–10], P<0.001). Prenatal oligohydramnios was strongly associated with both low pulmonary function (FEV1/FVCConclusion School-aged children with severe BPD showed airflow limitations and structural abnormalities despite no subjective respiratory symptoms. These results suggest that patients with a history of prenatal oligohydramnios or prolonged mechanical ventilation require extended follow-up.

Background: Very low birth weight infants (VLBWIs) continue to face high mortality risk influenced by the care quality of neonatal intensive care units (NICUs). Under-standing the impact of workload and regional differences on these rates is crucial for improving outcomes.Purpose: This study aimed to assess how the structural and staffing attributes of NICUs influence the mortality rates of VLBWIs, emphasizing the significance of the availability of medical personnel and the regional distribution of care facilities. Methods: Data from 69 Korean NICUs collected by the Korean Neonatal Network between January 2015 and December 2016 were retrospectively analyzed. The NICUs were classified by various parameters: capacity (small, medium, large), nurse-to-bed ratio (1–4), and regional location (A, B, C). Pediatrician staffing was also analyzed and NICUs categorized by beds per pediatrician into low (≤10), medium (11–15), and high (≥16). The NICUs were classified by mortality rates into high-performance (1st and 2nd quartiles) and low-performance (3rd and 4th quartiles). Demographic, perinatal, and neonatal outcomes were analyzed using multivariate logistic regression to explore the association between NICU characteristics and mortality rates. Results: This study included 4,745 VLBWIs (mean gestational age, 28.4 weeks; mean birth weight, 1,088 g; 55.4% male) and found significant variations in survival rates across NICUs linked to performance and staffing levels. High-performing NICUs, often with lower bed-to-staff ratios and advanced care levels, had higher survival rates. Notably, NICUs with 2 rather than 1 neonatologist were associated with reduced mortality rates. The study also underscored regional disparities, with NICUs in certain areas showing less favorable survival rates. Conclusion Adequate NICU staffing and proper facility location are key to lowering the number of VLBWI deaths. Enhancing staffing and regional healthcare equity is crucial for improving the survival of this population.

Background and Objectives: Kawasaki disease (KD) is an acute vasculitis that primarily affects children under age 5 years. Approximately 20–25% of untreated children with KD and 3–5% of those treated with intravenous immunoglobulin therapy develop coronary artery aneurysms (CAAs). The prevalence of CAAs is much higher in male than in female patients with KD, but the underlying factors contributing to susceptibility to CAAs in patients with KD remain unclear. This study aimed to identify sex-specific susceptibility loci associated with CAAs in KD patients. Methods: A sex-stratified genome-wide association study (GWAS) was performed using previously obtained GWAS data from 296 KD patients and a new replication study in an independent set of 976 KD patients by comparing KD patients without CAA (controls) and KD patients with aneurysms (internal diameter ≥5 mm) (cases). Results: Six male-specific susceptibility loci, PDE1C, NOS3, DLG2, CPNE8, FUNDC1, and GABRQ (odds ratios [ORs], 2.25–9.98; p=0.00204–1.96×10−6 ), and 2 female-specific susceptibility loci, SMAD3 (OR, 4.59; p=0.00016) and IL1RAPL1 (OR, 4.35; p=0.00026), were significantly associated with CAAs in patients with KD. In addition, the numbers of CAA risk alleles additively contributed to the development of CAAs in patients with KD. Conclusions A sex-stratified GWAS identified 6 male-specific (PDE1C, NOS3, DLG2, CPNE8, FUNDC1, and GABRQ) and 2 female-specific (SMAD3 and IL1RAPL1) CAA susceptibility loci in patients with KD.

Background and Objectives: Kawasaki disease (KD) is an acute vasculitis that primarily affects children under age 5 years. Approximately 20–25% of untreated children with KD and 3–5% of those treated with intravenous immunoglobulin therapy develop coronary artery aneurysms (CAAs). The prevalence of CAAs is much higher in male than in female patients with KD, but the underlying factors contributing to susceptibility to CAAs in patients with KD remain unclear. This study aimed to identify sex-specific susceptibility loci associated with CAAs in KD patients. Methods: A sex-stratified genome-wide association study (GWAS) was performed using previously obtained GWAS data from 296 KD patients and a new replication study in an independent set of 976 KD patients by comparing KD patients without CAA (controls) and KD patients with aneurysms (internal diameter ≥5 mm) (cases). Results: Six male-specific susceptibility loci, PDE1C, NOS3, DLG2, CPNE8, FUNDC1, and GABRQ (odds ratios [ORs], 2.25–9.98; p=0.00204–1.96×10−6 ), and 2 female-specific susceptibility loci, SMAD3 (OR, 4.59; p=0.00016) and IL1RAPL1 (OR, 4.35; p=0.00026), were significantly associated with CAAs in patients with KD. In addition, the numbers of CAA risk alleles additively contributed to the development of CAAs in patients with KD. Conclusions A sex-stratified GWAS identified 6 male-specific (PDE1C, NOS3, DLG2, CPNE8, FUNDC1, and GABRQ) and 2 female-specific (SMAD3 and IL1RAPL1) CAA susceptibility loci in patients with KD.