1.Permanent Congenital Hypothyroidism in Very Low Birth Weight Infants: A Single Center’s Experience
Joo Hyung ROH ; Tae-Gyeong KIM ; Keon Hee SEOL ; Chae Young KIM ; Soo Hyun KIM ; Ji Yoon JEONG ; Ja Hye KIM ; Euiseok JUNG ; Jin-Ho CHOI ; Byong Sop LEE
Neonatal Medicine 2025;32(1):30-38
Purpose:
Congenital hypothyroidism (CH) is a major preventable cause of intellectual disability, particularly in very low birth weight (VLBW) infants, who are at increased risk due to hypothalamic-pituitary-thyroid axis immaturity. Early differentiation between transient CH (TCH) and permanent CH (PCH) is crucial to optimize L-thyroxine (LT4) treatment duration. This study aimed to determine the incidence of PCH among Korean VLBW infants and to identify clinical factors that may aid in distinguishing TCH from PCH.
Methods:
This retrospective cohort study included VLBW infants diagnosed with CH and treated with LT4 at a single tertiary neonatal intensive care unit between 2011 and 2020. Infants requiring LT4 beyond 3 years were classified as PCH, while those who discontinued earlier were considered TCH. Clinical characteristics, neonatal morbidities, and thyroid-related parameters were compared between the groups.
Results:
Among 1,292 VLBW infants, 122 (9.4%) were diagnosed with CH. After excluding deaths and those lost to follow-up, 73 infants were included in the final analysis (TCH, n=50; PCH, n=23). The PCH group had a significantly higher mean gestational age and greater LT4 requirements at both 12 and 36 months of age. Major anomalies were more frequently observed in PCH infants, including congenital heart defects. In multivariate analysis, higher gestational age, the presence of major anomalies, screening thyroid-stimulating hormone (TSH) >10 μIU/mL, and higher LT4 dose at 36 months were significantly associated with PCH.
Conclusion
The incidence of PCH in Korean VLBW infants was relatively higher than that reported in previous studies studies. Screening TSH level and LT4 dose requirements may support individualized follow-up and help distinguish PCH from TCH.
2.Permanent Congenital Hypothyroidism in Very Low Birth Weight Infants: A Single Center’s Experience
Joo Hyung ROH ; Tae-Gyeong KIM ; Keon Hee SEOL ; Chae Young KIM ; Soo Hyun KIM ; Ji Yoon JEONG ; Ja Hye KIM ; Euiseok JUNG ; Jin-Ho CHOI ; Byong Sop LEE
Neonatal Medicine 2025;32(1):30-38
Purpose:
Congenital hypothyroidism (CH) is a major preventable cause of intellectual disability, particularly in very low birth weight (VLBW) infants, who are at increased risk due to hypothalamic-pituitary-thyroid axis immaturity. Early differentiation between transient CH (TCH) and permanent CH (PCH) is crucial to optimize L-thyroxine (LT4) treatment duration. This study aimed to determine the incidence of PCH among Korean VLBW infants and to identify clinical factors that may aid in distinguishing TCH from PCH.
Methods:
This retrospective cohort study included VLBW infants diagnosed with CH and treated with LT4 at a single tertiary neonatal intensive care unit between 2011 and 2020. Infants requiring LT4 beyond 3 years were classified as PCH, while those who discontinued earlier were considered TCH. Clinical characteristics, neonatal morbidities, and thyroid-related parameters were compared between the groups.
Results:
Among 1,292 VLBW infants, 122 (9.4%) were diagnosed with CH. After excluding deaths and those lost to follow-up, 73 infants were included in the final analysis (TCH, n=50; PCH, n=23). The PCH group had a significantly higher mean gestational age and greater LT4 requirements at both 12 and 36 months of age. Major anomalies were more frequently observed in PCH infants, including congenital heart defects. In multivariate analysis, higher gestational age, the presence of major anomalies, screening thyroid-stimulating hormone (TSH) >10 μIU/mL, and higher LT4 dose at 36 months were significantly associated with PCH.
Conclusion
The incidence of PCH in Korean VLBW infants was relatively higher than that reported in previous studies studies. Screening TSH level and LT4 dose requirements may support individualized follow-up and help distinguish PCH from TCH.
3.Permanent Congenital Hypothyroidism in Very Low Birth Weight Infants: A Single Center’s Experience
Joo Hyung ROH ; Tae-Gyeong KIM ; Keon Hee SEOL ; Chae Young KIM ; Soo Hyun KIM ; Ji Yoon JEONG ; Ja Hye KIM ; Euiseok JUNG ; Jin-Ho CHOI ; Byong Sop LEE
Neonatal Medicine 2025;32(1):30-38
Purpose:
Congenital hypothyroidism (CH) is a major preventable cause of intellectual disability, particularly in very low birth weight (VLBW) infants, who are at increased risk due to hypothalamic-pituitary-thyroid axis immaturity. Early differentiation between transient CH (TCH) and permanent CH (PCH) is crucial to optimize L-thyroxine (LT4) treatment duration. This study aimed to determine the incidence of PCH among Korean VLBW infants and to identify clinical factors that may aid in distinguishing TCH from PCH.
Methods:
This retrospective cohort study included VLBW infants diagnosed with CH and treated with LT4 at a single tertiary neonatal intensive care unit between 2011 and 2020. Infants requiring LT4 beyond 3 years were classified as PCH, while those who discontinued earlier were considered TCH. Clinical characteristics, neonatal morbidities, and thyroid-related parameters were compared between the groups.
Results:
Among 1,292 VLBW infants, 122 (9.4%) were diagnosed with CH. After excluding deaths and those lost to follow-up, 73 infants were included in the final analysis (TCH, n=50; PCH, n=23). The PCH group had a significantly higher mean gestational age and greater LT4 requirements at both 12 and 36 months of age. Major anomalies were more frequently observed in PCH infants, including congenital heart defects. In multivariate analysis, higher gestational age, the presence of major anomalies, screening thyroid-stimulating hormone (TSH) >10 μIU/mL, and higher LT4 dose at 36 months were significantly associated with PCH.
Conclusion
The incidence of PCH in Korean VLBW infants was relatively higher than that reported in previous studies studies. Screening TSH level and LT4 dose requirements may support individualized follow-up and help distinguish PCH from TCH.
4.Permanent Congenital Hypothyroidism in Very Low Birth Weight Infants: A Single Center’s Experience
Joo Hyung ROH ; Tae-Gyeong KIM ; Keon Hee SEOL ; Chae Young KIM ; Soo Hyun KIM ; Ji Yoon JEONG ; Ja Hye KIM ; Euiseok JUNG ; Jin-Ho CHOI ; Byong Sop LEE
Neonatal Medicine 2025;32(1):30-38
Purpose:
Congenital hypothyroidism (CH) is a major preventable cause of intellectual disability, particularly in very low birth weight (VLBW) infants, who are at increased risk due to hypothalamic-pituitary-thyroid axis immaturity. Early differentiation between transient CH (TCH) and permanent CH (PCH) is crucial to optimize L-thyroxine (LT4) treatment duration. This study aimed to determine the incidence of PCH among Korean VLBW infants and to identify clinical factors that may aid in distinguishing TCH from PCH.
Methods:
This retrospective cohort study included VLBW infants diagnosed with CH and treated with LT4 at a single tertiary neonatal intensive care unit between 2011 and 2020. Infants requiring LT4 beyond 3 years were classified as PCH, while those who discontinued earlier were considered TCH. Clinical characteristics, neonatal morbidities, and thyroid-related parameters were compared between the groups.
Results:
Among 1,292 VLBW infants, 122 (9.4%) were diagnosed with CH. After excluding deaths and those lost to follow-up, 73 infants were included in the final analysis (TCH, n=50; PCH, n=23). The PCH group had a significantly higher mean gestational age and greater LT4 requirements at both 12 and 36 months of age. Major anomalies were more frequently observed in PCH infants, including congenital heart defects. In multivariate analysis, higher gestational age, the presence of major anomalies, screening thyroid-stimulating hormone (TSH) >10 μIU/mL, and higher LT4 dose at 36 months were significantly associated with PCH.
Conclusion
The incidence of PCH in Korean VLBW infants was relatively higher than that reported in previous studies studies. Screening TSH level and LT4 dose requirements may support individualized follow-up and help distinguish PCH from TCH.
5.Permanent Congenital Hypothyroidism in Very Low Birth Weight Infants: A Single Center’s Experience
Joo Hyung ROH ; Tae-Gyeong KIM ; Keon Hee SEOL ; Chae Young KIM ; Soo Hyun KIM ; Ji Yoon JEONG ; Ja Hye KIM ; Euiseok JUNG ; Jin-Ho CHOI ; Byong Sop LEE
Neonatal Medicine 2025;32(1):30-38
Purpose:
Congenital hypothyroidism (CH) is a major preventable cause of intellectual disability, particularly in very low birth weight (VLBW) infants, who are at increased risk due to hypothalamic-pituitary-thyroid axis immaturity. Early differentiation between transient CH (TCH) and permanent CH (PCH) is crucial to optimize L-thyroxine (LT4) treatment duration. This study aimed to determine the incidence of PCH among Korean VLBW infants and to identify clinical factors that may aid in distinguishing TCH from PCH.
Methods:
This retrospective cohort study included VLBW infants diagnosed with CH and treated with LT4 at a single tertiary neonatal intensive care unit between 2011 and 2020. Infants requiring LT4 beyond 3 years were classified as PCH, while those who discontinued earlier were considered TCH. Clinical characteristics, neonatal morbidities, and thyroid-related parameters were compared between the groups.
Results:
Among 1,292 VLBW infants, 122 (9.4%) were diagnosed with CH. After excluding deaths and those lost to follow-up, 73 infants were included in the final analysis (TCH, n=50; PCH, n=23). The PCH group had a significantly higher mean gestational age and greater LT4 requirements at both 12 and 36 months of age. Major anomalies were more frequently observed in PCH infants, including congenital heart defects. In multivariate analysis, higher gestational age, the presence of major anomalies, screening thyroid-stimulating hormone (TSH) >10 μIU/mL, and higher LT4 dose at 36 months were significantly associated with PCH.
Conclusion
The incidence of PCH in Korean VLBW infants was relatively higher than that reported in previous studies studies. Screening TSH level and LT4 dose requirements may support individualized follow-up and help distinguish PCH from TCH.
6.Mortality of very low birth weight infants by neonatal intensive care unit workload and regional group status
Sung-Hoon CHUNG ; Chae Young KIM ; Yong-Sung CHOI ; Myung Hee LEE ; Jae Woo LIM ; Byong Sop LEE ; Ki-Soo KIM ;
Clinical and Experimental Pediatrics 2024;67(11):619-627
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.
7.Mortality of very low birth weight infants by neonatal intensive care unit workload and regional group status
Sung-Hoon CHUNG ; Chae Young KIM ; Yong-Sung CHOI ; Myung Hee LEE ; Jae Woo LIM ; Byong Sop LEE ; Ki-Soo KIM ;
Clinical and Experimental Pediatrics 2024;67(11):619-627
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.
8.Mortality of very low birth weight infants by neonatal intensive care unit workload and regional group status
Sung-Hoon CHUNG ; Chae Young KIM ; Yong-Sung CHOI ; Myung Hee LEE ; Jae Woo LIM ; Byong Sop LEE ; Ki-Soo KIM ;
Clinical and Experimental Pediatrics 2024;67(11):619-627
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.
9.Mortality of very low birth weight infants by neonatal intensive care unit workload and regional group status
Sung-Hoon CHUNG ; Chae Young KIM ; Yong-Sung CHOI ; Myung Hee LEE ; Jae Woo LIM ; Byong Sop LEE ; Ki-Soo KIM ;
Clinical and Experimental Pediatrics 2024;67(11):619-627
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.
10.Real-world effectiveness and safety of ustekinumab induction therapy for Korean patients with Crohn’s disease: a KASID prospective multicenter study
Kyunghwan OH ; Hee Seung HONG ; Nam Seok HAM ; Jungbok LEE ; Sang Hyoung PARK ; Suk-Kyun YANG ; Hyuk YOON ; You Sun KIM ; Chang Hwan CHOI ; Byong Duk YE ;
Intestinal Research 2023;21(1):137-147
Background/Aims:
We investigated the real-world effectiveness and safety of ustekinumab (UST) as induction treatment for Koreans with Crohn’s disease (CD).
Methods:
CD patients who started UST were prospectively enrolled from 4 hospitals in Korea. All enrolled patients received intravenous UST infusion at week 0 and subcutaneous UST injection at week 8. Clinical outcomes were assessed using Crohn’s Disease Activity Index (CDAI) scores at weeks 8 and 20 among patients with active disease (CDAI ≥150) at baseline. Clinical remission was defined as a CDAI <150, and clinical response was defined as a reduction in CDAI ≥70 points from baseline. Safety and factors associated with clinical remission at week 20 were also analyzed.
Results:
Sixty-five patients were enrolled between January 2019 and December 2020. Among 49 patients with active disease at baseline (CDAI ≥150), clinical remission and clinical response at week 8 were achieved in 26 (53.1%) and 30 (61.2%) patients, respectively. At week 20, 27 (55.1%) and 35 (71.4%) patients achieved clinical remission and clinical response, respectively. Twenty-seven patients (41.5%) experienced adverse events, with serious adverse events in 3 patients (4.6%). One patient (1.5%) stopped UST therapy due to poor response. Underweight (body mass index <18.5 kg/m2) (odds ratio [OR], 0.085; 95% confidence interval [CI], 0.014–0.498; P=0.006) and elevated C-reactive protein at baseline (OR, 0.133; 95% CI, 0.022–0.823; P=0.030) were inversely associated with clinical remission at week 20.
Conclusions
UST was effective and well-tolerated as induction therapy for Korean patients with CD.

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