Background: The incidence of preterm birth in Korea increased from 6.5% in 2013 to 9.7% in 2020. Very low birth weight (VLBW) infants, defined as those weighing < 1,500 g, are particularly vulnerable to numerous health risks. Breast milk provision reduces the incidence of complications in this vulnerable population. The objective of this study was to examine the rate and factors associated with breast milk provision at neonatal intensive care unit (NICU) discharge and to investigate its potential effects on growth and developmental outcomes at 18–24 months corrected age (CA). Methods: We conducted this cohort study using data from over 70 NICUs participating in the Korean Neonatal Network. VLBW infants born between January 2019 and December 2020 at a gestational age of 23 +0 to 31 +6 weeks were included. Discharge feeding types were analyzed of 2,490 infants, while follow-up assessments of growth and neurodevelopmental outcomes at 18–24 months of CA were available for 1,426 infants. Propensity score matching was used for comparative analysis. Results: The rate of breast milk provision at discharge among VLBW infants was 55.9% in 2019 and 56.5% in 2020. Factors that were positively associated with breast milk feeding included higher maternal education level and antenatal steroid use. In contrast, maternal hypertensive disorders, cesarean section, and severe neonatal morbidities (e.g., necrotizing enterocolitis) were correlated with lower breast milk feeding rates at the time of discharge.The provision of breast milk at discharge was not associated with a higher risk of suboptimal growth (below two standard deviations) compared to control infants at 18–24 months of CA. Neurodevelopmental assessments indicated that breast milk was associated with a reduced risk of developmental delay (adjusted odds ratio, 0.72; 95% confidence interval, 0.56–0.94) at follow-up. Conclusion Breast milk provision to VLBW infants at NICU discharge in Korea was comparable to that in other countries. This nationwide study highlights the critical role of breast milk in promoting the neurodevelopment of VLBW infants. Future efforts should focus on identifying the barriers to breast milk provision to improve health outcomes in vulnerable populations.

Purpose: This study aimed to assess prognostic factors associated with combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and to predict 5-year survival based on these factors. Materials and Methods: Patients who underwent definitive hepatectomy from 2006 to 2022 at a single institution was retrospectively analyzed. Inclusion criteria involved a pathologically confirmed diagnosis of cHCC-CCA. Results: A total of 80 patients with diagnosed cHCC-CCA were included in the analysis. The median progression-free survival was 15.6 months, while distant metastasis-free survival (DMFS), hepatic progression-free survival, and overall survival (OS) were 50.8, 21.5, and 85.1 months, respectively. In 52 cases of recurrence, intrahepatic recurrence was the most common initial recurrence (34/52), with distant metastasis in 17 cases. Factors associated with poor DMFS included tumor necrosis, lymphovascular invasion (LVI), perineural invasion, and histologic compact type. Postoperative carbohydrate antigen 19-9, tumor necrosis, LVI, and close/positive margin were associated with poor OS. LVI emerged as a key factor affecting both DMFS and OS, with a 5-year OS of 93.3% for patients without LVI compared to 35.8% with LVI. Based on these factors, a nomogram predicting 3-year and 5-year DMFS and OS was developed, demonstrating high concordance with actual survival in the cohort (Harrell C-index 0.809 for OS, 0.801 for DMFS, respectively). Conclusion The prognosis of cHCC-CCA is notably poor when combined with LVI. Given the significant impact of adverse features, accurate outcome prediction is crucial. Moreover, consideration of adjuvant therapy may be warranted for patients exhibiting poor survival and increased risk of local recurrence or distant metastasis.

Purpose: This study aimed to assess prognostic factors associated with combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and to predict 5-year survival based on these factors. Materials and Methods: Patients who underwent definitive hepatectomy from 2006 to 2022 at a single institution was retrospectively analyzed. Inclusion criteria involved a pathologically confirmed diagnosis of cHCC-CCA. Results: A total of 80 patients with diagnosed cHCC-CCA were included in the analysis. The median progression-free survival was 15.6 months, while distant metastasis-free survival (DMFS), hepatic progression-free survival, and overall survival (OS) were 50.8, 21.5, and 85.1 months, respectively. In 52 cases of recurrence, intrahepatic recurrence was the most common initial recurrence (34/52), with distant metastasis in 17 cases. Factors associated with poor DMFS included tumor necrosis, lymphovascular invasion (LVI), perineural invasion, and histologic compact type. Postoperative carbohydrate antigen 19-9, tumor necrosis, LVI, and close/positive margin were associated with poor OS. LVI emerged as a key factor affecting both DMFS and OS, with a 5-year OS of 93.3% for patients without LVI compared to 35.8% with LVI. Based on these factors, a nomogram predicting 3-year and 5-year DMFS and OS was developed, demonstrating high concordance with actual survival in the cohort (Harrell C-index 0.809 for OS, 0.801 for DMFS, respectively). Conclusion The prognosis of cHCC-CCA is notably poor when combined with LVI. Given the significant impact of adverse features, accurate outcome prediction is crucial. Moreover, consideration of adjuvant therapy may be warranted for patients exhibiting poor survival and increased risk of local recurrence or distant metastasis.

Purpose: This study aimed to assess prognostic factors associated with combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and to predict 5-year survival based on these factors. Materials and Methods: Patients who underwent definitive hepatectomy from 2006 to 2022 at a single institution was retrospectively analyzed. Inclusion criteria involved a pathologically confirmed diagnosis of cHCC-CCA. Results: A total of 80 patients with diagnosed cHCC-CCA were included in the analysis. The median progression-free survival was 15.6 months, while distant metastasis-free survival (DMFS), hepatic progression-free survival, and overall survival (OS) were 50.8, 21.5, and 85.1 months, respectively. In 52 cases of recurrence, intrahepatic recurrence was the most common initial recurrence (34/52), with distant metastasis in 17 cases. Factors associated with poor DMFS included tumor necrosis, lymphovascular invasion (LVI), perineural invasion, and histologic compact type. Postoperative carbohydrate antigen 19-9, tumor necrosis, LVI, and close/positive margin were associated with poor OS. LVI emerged as a key factor affecting both DMFS and OS, with a 5-year OS of 93.3% for patients without LVI compared to 35.8% with LVI. Based on these factors, a nomogram predicting 3-year and 5-year DMFS and OS was developed, demonstrating high concordance with actual survival in the cohort (Harrell C-index 0.809 for OS, 0.801 for DMFS, respectively). Conclusion The prognosis of cHCC-CCA is notably poor when combined with LVI. Given the significant impact of adverse features, accurate outcome prediction is crucial. Moreover, consideration of adjuvant therapy may be warranted for patients exhibiting poor survival and increased risk of local recurrence or distant metastasis.

Little is known about the transgenerational effects of maternal exposure to fine particulate matter (PM2.5) on offspring kidney health. This study investigated the effect of maternal administration of PM2.5 or PM2.5 with vitamin D during pregnancy and lactation on renal injury in rat dams and their offspring. Methods: Nine pregnant Sprague-Dawley rats received oral administration of normal saline, airborne PM2.5, or PM2.5 with vitamin D from gestational day 11 to postpartum day 21. Kidneys of rat dams (n = 3 for each group) and their male offspring (n = 5 for each group) were taken for analysis on postpartum or postnatal day 21. Results: Maternal PM2.5 exposure increased glomerular damage, tubulointerstitial injury, and cortical macrophage infiltration in both dams and pups; all increases were attenuated by vitamin D administration. In dam kidneys, PM2.5 increased the protein expression of vitamin D receptor (VDR), klotho, and tumor necrosis factor-α; vitamin D lessened these changes. The expressions of renin, nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor-kappa B (NF-κB) p50 decreased in rat dams exposed to PM2.5. In offspring kidneys, exposure to maternal PM2.5 reduced the expression of VDR, renin, angiotensin-converting enzyme (ACE), Nrf2, and NF-κB p50, but increased cytochrome P450 24A1 expression. Maternal vitamin D administration with PM2.5 enhanced VDR, ACE, and NF-κB p50 activities in pup kidneys. Conclusion: PM2.5 exposure during nephrogenesis may exert transgenerational renal impairment, and maternal vitamin D intake could attenuate PM2.5-induced kidney damage in mothers and their offspring.

Background and Objectives: A comprehensive survey of congenital heart disease (CHD) prevalence has not yet been conducted in South Korea. This study aimed to investigate the prevalence of CHDs in Korean children and lay the foundation for national CHD epidemiology. Methods: Target patients were infantile crucial CHDs, which include critical CHDs (requiring urgent procedures after birth with common hypoxemic defects) and diverse categorical defects excluding simple shunt defects. Data were obtained from the National Health Insurance Service over a 5-year period (2014–2018). Birth prevalence (new cases per 1,000 live births) of CHDs in Korea was analyzed and compared with that of other countries. Results: The birth prevalences of right heart obstructive defects (pulmonary valve stenosis and pulmonary atresia), conus anomalies (tetralogy of Fallot and double outlet right ventricle), and total anomalous pulmonary venous return showed significant increases in the East Asian group (P<0.001), whereas those of left heart obstructive defects (coarctation of aorta, aortic stenosis, and hypoplastic left heart syndrome), truncus anomalies (D-transposition of great artery and persistent truncus arteriosus), atrioventricular septal defect, and hypoplastic right heart syndrome were significantly decreased in the East Asian group (P<0.001). Conclusions The overall birth prevalence of crucial CHDs in Korea was similar to that of critical CHDs in previous studies from other countries. Some subtypes of right heart obstructive defects, left heart obstructive defects, and conotruncal anomalies showed significant differences between East Asian and Western populations. This study contributes to a foundation for national CHD epidemiology in Korean children.

Objective: Preterm births in the late preterm period comprise more than half of all preterm births. However, perinatal outcome evaluation between singleton and multiple pregnancies is limited. This study aimed to compare the perinatal outcomes of preterm pre-labor rupture of membranes (PPROM) between twin and singleton pregnancies at 34 weeks to 36 weeks and 6 days. Methods: This retrospective case-control study included women with preterm births at the Tertiary Hospital between July 2006 and December 2023. We analyzed and compared the maternal and neonatal characteristics, especially intertwined neonatal morbidity and mortality, with those of singletons. Results: There were 52 twin and 317 singleton pregnancies. Women with twin pregnancies had shorter median latencies and fewer cases of histological chorioamnionitis than those with singleton pregnancies. Compared to the ruptured sac babies of twins and singletons, unruptured sac babies of twins had longer hospital stays and were more likely to require respiratory support and resuscitation immediately after delivery. Conclusion Maternal outcomes of twins and singletons after PPROM differed in latency and histologic chorioamnionitis, whereas neonatal outcomes demonstrated more acute respiratory problems and longer hospital stays in twin babies with unruptured sacs. More cautious respiratory care is needed for infants with an unruptured sac immediately after birth.

PURPOSE: This study aimed to compare the accuracy of an alternative scan path with that of traditional scan paths to obtain a more accurate method for complete arch scans. MATERIALS AND METHODS: A mandibular stone cast, including tooth preparations for the inlay, crown, and fixed prosthesis, was scanned 10 times using four different scan paths (A, B, C, and D). The scans were converted into stereolithography files, resized, and superimposed onto a control file obtained from a desktop scanner. The scan time, total surface deviation, and local deviation of the mandibular teeth were measured. One-way analysis of variance (ANOVA) and Welch ANOVA were used for statistical analyses (α = .05). The relative standard deviation and standard error of the mean were calculated to evaluate accuracy. RESULTS: The total surface deviation differed significantly according to the scanning path despite a similar scan time. Path D had the highest accuracy and the most uniform color maps, showing minimal deformation of the digital model. Meanwhile, no significant differences were found in the local deviations in the individual tooth assessments, likely owing to issues with the superimposition method. CONCLUSION Among all scan paths, the scan path with the shortest distance from the starting point to the end point showed the smallest total surface deviation and the highest accuracy. No differences were observed in the deviations of specific teeth based on the scan path.

Objective: Preterm births in the late preterm period comprise more than half of all preterm births. However, perinatal outcome evaluation between singleton and multiple pregnancies is limited. This study aimed to compare the perinatal outcomes of preterm pre-labor rupture of membranes (PPROM) between twin and singleton pregnancies at 34 weeks to 36 weeks and 6 days. Methods: This retrospective case-control study included women with preterm births at the Tertiary Hospital between July 2006 and December 2023. We analyzed and compared the maternal and neonatal characteristics, especially intertwined neonatal morbidity and mortality, with those of singletons. Results: There were 52 twin and 317 singleton pregnancies. Women with twin pregnancies had shorter median latencies and fewer cases of histological chorioamnionitis than those with singleton pregnancies. Compared to the ruptured sac babies of twins and singletons, unruptured sac babies of twins had longer hospital stays and were more likely to require respiratory support and resuscitation immediately after delivery. Conclusion Maternal outcomes of twins and singletons after PPROM differed in latency and histologic chorioamnionitis, whereas neonatal outcomes demonstrated more acute respiratory problems and longer hospital stays in twin babies with unruptured sacs. More cautious respiratory care is needed for infants with an unruptured sac immediately after birth.

PURPOSE: This study aimed to compare the accuracy of an alternative scan path with that of traditional scan paths to obtain a more accurate method for complete arch scans. MATERIALS AND METHODS: A mandibular stone cast, including tooth preparations for the inlay, crown, and fixed prosthesis, was scanned 10 times using four different scan paths (A, B, C, and D). The scans were converted into stereolithography files, resized, and superimposed onto a control file obtained from a desktop scanner. The scan time, total surface deviation, and local deviation of the mandibular teeth were measured. One-way analysis of variance (ANOVA) and Welch ANOVA were used for statistical analyses (α = .05). The relative standard deviation and standard error of the mean were calculated to evaluate accuracy. RESULTS: The total surface deviation differed significantly according to the scanning path despite a similar scan time. Path D had the highest accuracy and the most uniform color maps, showing minimal deformation of the digital model. Meanwhile, no significant differences were found in the local deviations in the individual tooth assessments, likely owing to issues with the superimposition method. CONCLUSION Among all scan paths, the scan path with the shortest distance from the starting point to the end point showed the smallest total surface deviation and the highest accuracy. No differences were observed in the deviations of specific teeth based on the scan path.