Evaluating Novel SP-B and SP-C Synthetic Analogues for Pulmonary Surfactant Efficacy.

Pulmonary surfactants, a complex assembly of phospholipids and surfactant proteins such as SP-B and SP-C, are critical for maintaining respiratory system functionality by lowering surface tension (ST) and preventing alveolar collapse. Our study introduced five synthetic SP-B peptides and one SP-C peptide, leading to the synthesis of CHAsurf candidates (CHAsurf-1 to CHAsurf-5) for evaluation. We utilized a modified Wilhelmy balance test to assess the surface tension properties of the surfactants, measuring spreading rate, surface adsorption, and ST-area diagrams to comprehensively evaluate their performance. Animal experiments were performed on New Zealand white rabbits to test the efficacy of CHAsurf-4B, a variant chosen for its economic viability and promising ST reduction properties, comparable to Curosurf®. The study confirmed that higher doses of SP-B in CHAsurf-4 are associated with improved ST reduction. However, due to cost constraints, CHAsurf-4B was selected for in vivo assessment. The animal model revealed that CHAsurf-4B could restore alveolar structure and improve lung elasticity, akin to Curosurf®. Our research highlights the significance of cysteine residues and disulfide bonds in the structural integrity and function of synthetic SP-B analogues, offering a foundation for future surfactant therapy in respiratory disorders. This study's findings support the potential of CHAsurf-4B as a therapeutic agent, meriting further investigation to solidify its role in clinical applications.

Nationwide Long-Term Growth and Developmental Outcomes of Infants for Congenital Anomalies in the Digestive System and Abdominal Wall Defects With Surgery in Korea.

BACKGROUND: Infants with congenital anomalies of the digestive system and abdominal wall defects requiring surgery are at risk of growth and developmental delays. The aim of this study was to analyze long-term growth and developmental outcomes for infants with congenital anomalies of the digestive system and abdominal wall defects who underwent surgery in Korea. METHODS: We extracted data from the Korean National Health Insurance Service database for the years 2013-2019. Major congenital anomalies were defined according to the International Classification of Diseases-10 and surgery insurance claim codes. The χ² test and the Cochran-Armitage trend test were performed for data analysis. RESULTS: A total of 4,574 infants with major congenital anomalies in the digestive system and abodminal wall defects, who had undergone surgey, were reviewed. Anorectal obstruction/stenosis was the most prevalent anomaly (4.9 per 10,000 live births). The prevalence of congenital anomalies of the digestive system was 15.5 per 10,000 live births, and that of abdominal wall defects was 1.5 per 10,000 live births. Seven percent of infants with congenital anomalies in the digestive system died, of which those with diaphragmatic hernia had the highest mortality rate (18.8%). Among 12,336 examinations at 6, 12, 24, 36, 48, 60, and 72 months of age, 16.7% showed a weight below the 10th percentile, 15.8% had a height below the 10th percentile, and 13.2% had a head circumference below the 10th percentile. Abnormal developmental screening results were observed in 23.0% of infants. Infants with esophageal atresia with/without tracheoesophageal fistula most often had poor growth and development. Delayed development and cerebral palsy were observed in 490 (10.7%) and 130 (2.8%) infants respectively. Comparing the results of infants born in 2013 between their 24- and 72-month health examinations, the proportions of infants with poor height and head circumference growth increased by 6.5% and 5.3%, respectively, whereas those with poor weight growth and abnormal developmental results did not markedly change between the two examinations. CONCLUSION: Infants with congenital anomalies of the digestive system and abdominal wall defects exhibit poor growth and developmental outcomes until 72 months of age. Close monitoring and careful consideration of their growth and development after discharge are required.

Major Congenital Anomalies in Korean Livebirths in 2013-2014: Based on the National Health Insurance Database.

BACKGROUND: In Korea, there have been no reports comparing the prevalence of major congenital anomalies with other countries and no reports on surgical treatment and long-term mortality. We investigated the prevalence of 67 major congenital anomalies in Korea and compared the prevalence with that of the European network of population-based registries for the epidemiological surveillance of congenital anomalies (EUROCAT). We also investigated the mortality and age at death, the proportion of preterm births, and the surgical rate for the 67 major congenital anomalies. METHODS: Korean National Health Insurance claim data were obtained for neonates born in 2013-2014 and admitted within one-year-old. Sixty-seven major congenital anomalies were defined by medical diagnoses classified by International Classification of Diseases-10 codes according to the EUROCAT definition version 2014. Mortality and surgery were defined if any death or surgery claim code was confirmed until 2020. Poisson distribution was used to calculate the 95% confidence interval of the congenital anomaly prevalence. RESULTS: The total prevalence of the 67 major anomalies was 433.5/10,000 livebirths. When compared with the prevalence of each major anomaly in EUROCAT, the prevalence of spina bifida, atrial septal defect (ASD), congenital megacolon, hip dislocation and/or dysplasia and skeletal dysplasia were more than five times higher in Korea. In contrast, the prevalence of aortic atresia/interrupted aortic arch and gastroschisis was less than one-fifth in Korea. The proportion of preterm births was 15.7%; however, more than 40% of infants with anencephaly, annular pancreas and gastroschisis were preterm infants. Additionally, 29.2% of the major anomalies were admitted to the neonatal intensive care units at birth, and 25.6% received surgical operation. The mortality rate was 1.7%, and 78.2% of the deaths occurred within the first year of life. However, in neonates with tricuspid valve atresia and stenosis, duodenal atresia or stenosis, and diaphragmatic hernia, more than half died within their first month of life. ASD and ventricular septal defect were the most common anomalies, and trisomy 18 and hypoplastic left heart syndrome were the most fatal anomalies. All infants with aortic atresia/interrupted aortic arch and conjoined twins received surgery. CONCLUSION: The proportion of surgeries, preterm births and mortality was high in infants with major congenital anomalies. The establishment of a national registry of congenital anomalies and systematic support by national medical policies are needed for infants with major congenital anomalies in Korea.

Artificial Intelligence-Driven Respiratory Distress Syndrome Prediction for Very Low Birth Weight Infants: Korean Multicenter Prospective Cohort Study.

BACKGROUND: Respiratory distress syndrome (RDS) is a disease that commonly affects premature infants whose lungs are not fully developed. RDS results from a lack of surfactant in the lungs. The more premature the infant is, the greater is the likelihood of having RDS. However, even though not all premature infants have RDS, preemptive treatment with artificial pulmonary surfactant is administered in most cases. OBJECTIVE: We aimed to develop an artificial intelligence model to predict RDS in premature infants to avoid unnecessary treatment. METHODS: In this study, 13,087 very low birth weight infants who were newborns weighing less than 1500 grams were assessed in 76 hospitals of the Korean Neonatal Network. To predict RDS in very low birth weight infants, we used basic infant information, maternity history, pregnancy/birth process, family history, resuscitation procedure, and test results at birth such as blood gas analysis and Apgar score. The prediction performances of 7 different machine learning models were compared, and a 5-layer deep neural network was proposed in order to enhance the prediction performance from the selected features. An ensemble approach combining multiple models from the 5-fold cross-validation was subsequently developed. RESULTS: Our proposed ensemble 5-layer deep neural network consisting of the top 20 features provided high sensitivity (83.03%), specificity (87.50%), accuracy (84.07%), balanced accuracy (85.26%), and area under the curve (0.9187). Based on the model that we developed, a public web application that enables easy access for the prediction of RDS in premature infants was deployed. CONCLUSIONS: Our artificial intelligence model may be useful for preparations for neonatal resuscitation, particularly in cases involving the delivery of very low birth weight infants, as it can aid in predicting the likelihood of RDS and inform decisions regarding the administration of surfactant.

Birth Rate Transition in the Republic of Korea: Trends and Prospects.

BACKGROUND: In Korea, the birth rate is declining at an alarming pace. This study aimed to investigate the changes and trends in the population count, number of births, and birth rate in Korea, in the past and future. METHODS: Data regarding the total number of births, crude birth rate, and total fertility rate were collected from the "Statistics Korea Census" of the national statistical portal, census report, and Statistics Korea's "2020 Population Trend Survey for 1981-2020, provisional results of birth and death statistics." We used the Organisation for Economic Co-operation and Development 2019 Family Database for the TFR. To develop a better understanding of the data in this study, we classified it according to the modern history of Korea. RESULTS: The changes and trends in the number of births and fertility rate in Korea, after liberation, were due to the birth control policy that restricted births. In Korea's low fertility society, which began in the mid-2000s, the fertility rate dropped to below 0.84 in 2020, despite policies to improve the quality of the population. The death toll has reached 300,000, entering an era of population decline. CONCLUSION: As we enter the era of population decline, we are in a direction that will cause various socioeconomic problems, from demographic problems to future population decline.

Single-dose prophylactic ibuprofen therapy for patent ductus arteriosus in preterm infants.

This study aimed to evaluate the short-term morbidities and efficacy of single-dose prophylactic intravenous ibuprofen for patent ductus arteriosus (PDA) on the first day of life in preterm infants. Data of 69 preterm infants with birth weight < 1250 g and gestational age < 30 weeks admitted to the neonatal intensive care unit were analyzed. Of these, 37 infants were assigned to the prophylactic treatment (PT) group and 32 were assigned to the nonprophylactic treatment (non-PT) group. Only the PT group administered intravenous ibuprofen (10 mg/kg) once within 6 hours after birth. Until postnatal day 7, ductal closure occurred in 11 (34.4%) infants in the non-PT group, and in 35 (94.6%) infants in the PT group, of which 30 (81.1%) infants had ductal closure on postnatal day 1. There were 2 (5.4%) infants in the PT group and 9 (28.1%) in the non-PT group who needed ibuprofen treatment due to moderate-to-large PDA after postnatal day 7. Preterm infants in the PT group were less likely to develop an intraventricular hemorrhage (≥grade 2) (adjusted odds ratio 0.007, 95% confidence interval 0.01-0.45), had a shorter duration of invasive ventilatory support and central venous catheter, and earlier postnatal age to achieve feeding of 50 and 100 mL/kg/day compared with those in the non-PT group. Single-dose prophylactic intravenous ibuprofen on the first day of life decreased the occurrence of a persistent PDA and intraventricular hemorrhage (≥grade 2), and reduced the duration of invasive ventilatory support, central venous catheter use, and hospital stay.

Survey of Korean pediatrician's perceptions of barriers to and improvements in breastfeeding.

BACKGROUND: Although the benefits of breastfeeding are broadly acknowledged with the efforts of the government and several medical societies, the rate of exclusive breastfeeding through 6 months is lower in Korea than in developed countries. PURPOSE: This study aimed to investigate pediatricians' perceptions of breastfeeding barriers and the current breastfeeding counseling environment and propose government policies to encourage breastfeeding in Korea. METHODS: Fourteen survey questions were developed during meetings of Korean Society of Breastfeeding Medicine experts. The Korean Pediatric Society emailed a structured questionnaire to domestic pediatricians registered as official members of the Korean Pediatric Society on May 4, 2021, and June 3, 2021. This study examined the survey responses received from 168 pediatricians. RESULTS: The 168 respondents included 62 professors, 53 paid doctors, and 53 private physicians. Breastfeeding was recommended by 146 Korean pediatricians (86.9%). However, only 99 responders (59%) currently provide breastfeeding counseling in hospitals. Most respondents stated providing less than 15 minutes of breastfeeding counseling time in the clinic. Moreover, 89.88% of the respondents responded that they would participate in breastfeeding counseling education if an appropriate breastfeeding counseling program was newly established. CONCLUSION: This study showed that, although Korean pediatricians had a positive attitude toward breastfeeding, limited counseling was provided for parents. Along with policy support to improve the medical environment through the establishment of an appropriate breastfeeding counseling program, high-quality counseling and an increased breastfeeding rate are expected.

Surfactant Treatment Shows Higher Correlation Between Ventilator and EIT Tidal Volumes in an RDS Animal Model.

Neonatal respiratory distress syndrome (RDS) is a condition of pulmonary surfactant insufficiency in the premature newborn. As such, artificial pulmonary surfactant administration is a key treatment. Despite continued improvement in the clinical outcomes of RDS, there are currently no established bedside tools to monitor whether pulmonary surfactant is effectively instilled throughout the lungs. Electrical impedance tomography (EIT) is an emerging technique in which physiological functions are monitored on the basis of temporal changes in conductivity of different tissues in the body. In this preliminary study, we aimed to assess how EIT tidal volumes correlate with ventilator tidal volumes in an RDS animal model, namely untreated, surfactant-treated, and normal control rabbit pups. Tidal volumes were measured simultaneously on an EIT system and a mechanical ventilator and compared at different peak inspiratory pressures. The linear correlation between tidal volumes measured by EIT and by ventilator had an R 2 of 0.71, 0.76 and 0.86 in the untreated, surfactant-treated, and normal control groups, respectively. Bland-Altman analysis showed a good correlation between the measurements obtained with these two modalities. The intraclass correlation coefficients (ICC) between ventilator tidal volume and EIT tidal volume were 0.83, 0.87, and 0.93 (all p < 0.001) in the untreated, surfactant-treated, and normal control groups, respectively, indicating that the higher ICC value, the better inflated status of the lung. In conclusion, we demonstrated that EIT tidal volume correlated with ventilator tidal volume. ICC was higher in the surfactant treated group.

Survey on the Status of Breastfeeding in Korean Medical Institution Workers.

BACKGROUND: Human breast milk is essential and provides irreplaceable nutrients for early humans. However, breastfeeding is not easy for various reasons in medical institution environments. Therefore, in order to improve the breastfeeding environment, we investigated the difficult reality of breastfeeding through questionnaire responses from medical institution workers. METHODS: A survey was conducted among 179 medical institution workers with experience in childbirth within the last five years. The survey results of 175 people were analyzed, with incoherent answers excluded. RESULTS: Of the 175 people surveyed, a total of 108 people (61.7%) worked during the day, and 33 people (18.9%) worked in three shifts. Among 133 mothers who stayed with their babies in the same nursing room, 111 (93.3%) kept breastfeeding for more than a month, but among those who stayed apart, only 10 (71.4%) continued breastfeeding for more than a month (P = 0.024). Ninety-five (88.0%) of daytime workers, 32 (94.1%) two-shift workers, and 33 (100%) three-shift workers continued breastfeeding for more than a month (P = 0.026). Workers in general hospitals tended to breastfeed for significantly longer than those that worked in tertiary hospitals (P = 0.003). A difference was also noted between occupation categories (P = 0.019), but a more significant difference was found in the comparison between nurses and doctors (P = 0.012). Longer breastfeeding periods were noted when mothers worked three shifts (P = 0.037). Depending on the period planned for breastfeeding prior to childbirth, the actual breastfeeding maintenance period after birth showed a significant difference (P = 0.002). Of 112 mothers who responded to the question regarding difficulties in breastfeeding after returning to work, 87 (77.7%) mentioned a lack of time caused by being busy at work, 82 (73.2%) mentioned the need for places and appropriate circumstances. CONCLUSION: In medical institutions, it is recommended that environmental improvements in medical institutions, the implementation of supporting policies, and the provision of specialized education on breastfeeding are necessary to promote breastfeeding.

Antenatal Betamethasone Induces Increased Surfactant Proteins and Decreased Foxm1 Expressions in Fetal Rabbit Pups.

Introduction: Antenatal steroid improves respiratory distress syndrome in preterm infants. The molecular mechanism of the process is not well established. The aim of this study is to investigate the possible association between antenatal steroid and fetal Forkhead box M1(Foxm1) expression. Materials and methods: An animal study using mated pregnant New Zealand white rabbits and their fetuses was designed. Fourteen mother rabbits were assigned to four groups to undergo a cesarean section. In groups 1, 2, and 3, preterm pups were harvested on day 27 of gestation. In group 4, term pups were harvested on day 31. Antenatal maternal intramuscular injection was performed in groups 2 (normal saline) and 3 (betamethasone). Using qRT-PCR and Western blot, mRNA transcription and protein expression of surfactant protein (SP) A, B, C, and Foxm1 were compared between the pups of those four groups. Results: Sixty two fetal rabbits were harvested. One-way ANOVA test showed higher mRNA transcription of SPs in groups 3 and 4 than groups 1 and 2. Significantly lower Foxm1 mRNA transcription and protein expression were observed in group 3 or 4 compared with group 1 or 2. Conclusion: Decreased Foxm1 expression was associated in an antenatal betamethasone animal model.

Effects of depth of neuromuscular blockade on the BIS-guided propofol requirement: A randomized controlled trial.

BACKGROUND: Deep neuromuscular blockade is considered beneficial for improving the surgical space condition during laparoscopic surgery. Adequacy of the surgical space condition may affect the anesthetists' decision regarding titration of depth of anesthesia. We investigated whether deep neuromuscular blockade reduces the propofol requirement under bispectral index monitoring compared to moderate neuromuscular blockade. METHODS: Adult patients undergoing elective laparoscopic colorectal surgery were randomly allocated to a moderate or deep group. A train-of-four count of 1-2 in the moderate group, and a post-tetanic count of 1-2 in the deep group, were maintained by continuous infusion of rocuronium. The induction and maintenance of anesthesia were achieved by target-controlled infusion of propofol and remifentanil. The dose of propofol was adjusted to maintain the bispectral index in the range of 40-50. The remifentanil dose was titrated to maintain the systolic blood pressure to within 20% of the ward values. RESULTS: A total of 82 patients were included in the analyses. The mean±SD dose of propofol was 7.54 ±â€Š1.66 and 7.42 ±â€Š1.01 mg·kg-1·h-1 in the moderate and deep groups, respectively (P = .104). The mean±SD dose of remifentanil was 4.84 ±â€Š1.74 and 4.79 ±â€Š1.77 µg kg-1 h-1 in the moderate and deep groups, respectively (P = .688). In comparison to the moderate group, the deep group showed significantly lower rates of intraoperative patient movement (42.9% vs 22.5%, respectively, P = .050) and additional neuromuscular blocking agent administration (76% vs 53%, respectively, P = .007). Postoperative complications, including pulmonary complications, wound problems and reoperation, were not different between the two groups. CONCLUSION: Deep neuromuscular blockade did not reduce the bispectral index-guided propofol requirement compared to moderate neuromuscular blockade during laparoscopic colon surgery, despite reducing movement of the patient and the requirement for a rescue neuromuscular blocking agent. TRIAL REGISTRATION: Clinicaltrials.gov (NCT03890406).

Congenital Anomalies in Very-Low-Birth-Weight Infants: A Nationwide Cohort Study.

BACKGROUND: Management of newborn infants with congenital anomalies is challenging and requires a multidisciplinary approach. The prevalence of congenital anomalies in very-low-birth-weight infants (VLBWIs; birth weight <1,500 g) has been rarely reported. OBJECTIVES: The aim of this study was to investigate the epidemiology of congenital anomalies in VLBWIs and the association with early mortality and major morbidities. STUDY DESIGN: A prospective cohort study was performed using data collected from 70 centers registered in the Korean Neonatal Network. Data from the VLBWIs with major congenital anomalies (n = 289) and the controls (n = 867), selected by 1:3 frequency matching for gestational age, were compared. RESULTS: The overall prevalence of major congenital anomalies in VLBWIs was 34.9 per 1,000 live births (289/8,156). The top 2 ranked subgroups of congenital anomalies were the digestive system (31.7%) and congenital heart defects (27.7%), followed by chromosomal anomalies, genitourinary tract defect, central nervous system, other anomalies, undefined, and respiratory system. The group with congenital anomalies had a higher mortality (40.7%) than the control group (11.1%). Each subgroup of congenital anomalies, except for chromosomal anomalies, increased the risk of mortality, with the highest odds ratio associated with "other" anomalies, which includes hydrops fetalis and congenital diaphragmatic hernia. In the multivariate analysis, congenital anomaly was a risk factor for mortality, bronchopulmonary dysplasia, and severe-grade intraventricular hemorrhage. VLBWIs with congenital anomaly demonstrated impaired in-hospital growth as compared with the control group. CONCLUSION: Congenital anomaly increased the risk of in-hospital mortality and was associated with short-term neonatal morbidities in the VLBWIs.

Deep neuromuscular block improves angiographic image quality during endovascular coiling of unruptured cerebral aneurysm: a randomized clinical trial.

BACKGROUND: Neuromuscular block (NMB) used during general anesthesia induces transient skeletal muscle paralysis, but patient movements during endovascular coiling still occur to some degree. Compared with moderate NMB, deep NMB may further improve the intervention condition during endovascular coiling for unruptured cerebral aneurysms; however, little research has focused on the angiographic image quality. METHODS: This prospective, randomized, double-blind clinical trial included 58 patients treated for unruptured cerebral aneurysms with endovascular coiling under general anesthesia. Patients were randomly allocated to either the deep NMB group (post-tetanic count 1 or 2) or the moderate NMB group (train-of-four 1 or 2). The primary outcome was the proportion of patients with a satisfactory intervention condition assessed by surgeons after the procedure using a 5-point intervention condition rating scale (ICRS) from 1 (unable to obtain image) to 5 (optimal); ICRS 5 was defined as satisfactory. RESULTS: There were significantly more cases of satisfactory intervention condition in the deep NMB group than in the moderate NMB group (82.1% vs 51.7%, p=0.015). The frequency of each ICRS score was significantly different between the groups (ICRS 5/4/3/2/1: 23/5/0/0/0 vs 15/9/2/3/0, p=0.035). The incidence of major patient movement requiring rescue muscle relaxant was 10.3% in the moderate NMB group and 0% in the deep NMB group (p=0.237). The drugs used to maintain hemodynamic stability were not significantly different between the two groups. CONCLUSIONS: Deep NMB improves the intervention condition during endovascular coiling by improving the image quality.

History of Pulmonary Surfactant Replacement Therapy for Neonatal Respiratory Distress Syndrome in Korea.

Neonatal respiratory distress syndrome (RDS) is a disease that is unique to newborn infants. It is caused by a deficiency of pulmonary surfactant (PS), which is usually ready to be activated around the perinatal period. Until RDS was more clearly understood, it was not known why premature infants died from respiratory failure, although pathology revealed hyaline membranes in the alveoli. Surprisingly, the era of PS replacement therapy began only relatively recently. The first clinical trial investigating neonatal RDS was conducted in 1980. Since then, newborn survival has improved dramatically, which has led to significant advances in the field of neonatology. The present comprehensive review addresses PS, from its discovery to the application of artificial PS in newborns with RDS. It also reviews the history of PS in Korea, including its introduction, various commercial products, present and past research, newborn registries, and health insurance issues. Finally, it describes the inception of the Korean Society of Neonatology and future directions of research and treatment.

Maternal Exposure to Particulate Matter during Pregnancy and Adverse Birth Outcomes in the Republic of Korea.

Air pollution has become a global concern due to its association with numerous health effects. We aimed to assess associations between birth outcomes in Korea, such as preterm births and birth weight in term infants, and particulate matter < 10 µm (PM10). Records from 1,742,183 single births in 2010⁻2013 were evaluated. Mean PM10 concentrations during pregnancy were calculated and matched to birth data by registered regions. We analyzed the frequency of birth outcomes between groups using WHO criteria for PM10 concentrations with effect sizes estimated using multivariate logistic regression. Women exposed to PM10 > 70 µg/m³ during pregnancy had a higher rate of preterm births than women exposed to PM10 ≤ 70 µg/m³ (7.4% vs. 4.7%, P < 0.001; adjusted odds ratio (aOR) 1.570; 95% confidence interval (CI): 1.487⁻1.656). The rate of low birth weight in term infants increased when women were exposed to PM10 > 70 µg/m³ (1.9% vs. 1.7%, P = 0.278), but this difference was not statistically significant (aOR 1.060, 95% CI: 0.953⁻1.178). In conclusion, PM10 exposure > 70 µg/m³ was associated with preterm births. Further studies are needed to explore the pathophysiologic mechanisms and guide policy development to prevent future adverse effects on birth outcomes.

Trends in Birth Weight and the Incidence of Low Birth Weight and Advanced Maternal Age in Korea between 1993 and 2016.

BACKGROUND: As the aging society progresses, the average age of mothers is also increasing. Advanced maternal age has been known to be associated with perinatal outcomes, as well as birth weight (BW). In this study, we aimed to investigate the perinatal factors associated with low birth weight infants (LBWIs) using birth statistics of the Korean population. METHODS: Birth statistics between 1993 and 2016 from the Korean Statistical Information Service were reviewed. We investigated 12,856,614 data points, which included the number of births, BWs, percentage of preterm births and LBWIs, multiple pregnancies, and maternal age. RESULTS: The proportion of LBWIs delivered by mothers of advanced maternal age has gradually increased since 1993. In addition, the proportion of older mothers (≥ 35 years old) giving birth to LBWIs has increased over the years. Average BW has a negative correlation with the ratio of preterm births, LBW, multiple births, and advanced maternal age. The mean BW also has a negative correlation with maternal age. CONCLUSION: This study shows that the average BW continues to decline, and the incidence of LBWIs is increasing in Korea since 1993. This study also revealed that several perinatal factors, including percentage of preterm births, LBWIs, multiple births, and maternal age influence the mean BW. Although this study did not investigate the effects of decreasing mean BW on perinatal health, future research is worth discussing.

Association of Surfactant Protein with Expression of Hoxa5 and Hoxb5 in Rabbit Fetal Lung.

Hox genes regulate organ formation and identity of the embryo, and expressed in specific temporo-spatial patterns in the developing embryo. We compared the expression levels of the Hoxa5, Hoxb5, surfactant protein (SP)-A, and SP-B genes in immature and mature rabbit fetal lung tissues, and to uncover roles for Hoxa5, Hoxb5, SP-A, and SP-B. Cesarean sections were performed after rabbits were divided into two groups of 30-31 days of gestation (term group, n = 24) and 26-27 days of gestation (preterm group, n = 24). mRNA levels of Hoxa5, Hoxb5, SP-A, and SP-B were compared by quantitative reverse transcriptase polymerase chain reaction, and protein expression of Hoxa5 and Hoxb5 was compared by western blot analysis. Fetal lung tissue histology was observed by hematoxylin and eosin (H&E) staining. The relative expression ratios of SP-A and SP-B mRNA in the term to preterm groups were 2.45:1 and 2.94:1, respectively. Hoxb5 mRNA and protein levels decreased in the term group, with a relative expression ratio of 0.48:1 and 0.50:1, however, Hoxa5 mRNA and protein levels increased in the term group with a relative expression ration of 2.99:1 and 2.33:1, respectively, for the term to preterm groups. Moreover, a significant positive correlation was found between the expression of Hoxa5 and SP-A, SP-B in the term group. Hoxa5 gene may be essential for the expression of SP-A and SP-B in term rabbits. The Hoxb5 gene may be an important factor for lung maturation in preterm rabbits.

A retrospective study on the effects of exclusive donor human milk feeding in a short period after birth on morbidity and growth of preterm infants during hospitalization.

The risks and benefits of feeding preterm formula (PF) versus donor human milk (DHM) in preterm infants are uncertain, and studies evaluating the efficacy of DHM to the morbidities and growth of preterm infants in the neonatal intensive care unit are confused by the need for milk fortification. We aimed to determine and compare the outcome of short-term morbidities in neonatal intensive care unit and growth between premature infants fed exclusively DHM only until a volume of 130 mL/kg/d of enteral feeding was achieved and infants fed with a PF mix after birth. The data of 132 infants with low birth weight of <1500 g and gestational age of less than 32 weeks were considered. Ninety infants were analyzed, of which 86 were discharged alive. The DHM group (n = 36) was made up of infants who were fed exclusively with DHM, whereas the PF group (n = 54) consisted of infants who were fed with a combination of PF and either DHM or human milk, until a volume of 130 mL/kg/d of enteral feeding was achieved. Once feeding in the DHM group progressed to volumes greater than 130 mL/kg/d, infants were fed fortified DHM and PF alternately. One infant (2.8%) in the DHM group had late-onset sepsis or necrotizing enterocolitis compared with 21 (38.9%) in the PF group (adjusted odds ratio 0.05, 95% confidence interval 0.01-0.41); 13 (36.1%) infants in the DHM group had bronchopulmonary dysplasia compared with 38 (70.4%) in the PF group (odds ratio 0.18, 95% confidence interval 0.05-0.41). Although the DHM group demonstrated a comparatively lower rate of weight gain, head circumference increment, and height increment from birth to the age at which an enteral feeding volume of 130 mL/kg/d was achieved, there were no significant differences in these values at 36 weeks' postmenstrual age between both groups.

Improvement in the Survival Rates of Very Low Birth Weight Infants after the Establishment of the Korean Neonatal Network: Comparison between the 2000s and 2010s.

The survival rate (SR) of very low birth weight infants (VLBWIs) and extremely low birth weight infants (ELBWIs) is a health indicator of neonatal intensive care unit (NICU) outcomes. The Korean Neonatal Network (KNN) was established in 2013, and a system has been launched to manage the registration and quality improvement of VLBWIs. The SR of the VLBWIs significantly increased to 85.7% in the 2010s compared with 83.0% in the 2000s. There was also a significant increase in the SR of the ELBWIs from 66.1% to 70.7%. The equipment, manpower, and assistance systems of NICUs also improved in quantity and quality. In the international comparison of the SRs of VLBWIs, the SRs were 93.8%, 92.2%, 90.2%, 89.4%, 86.4%, 85.1%, and 80.6% in Japan, Australia and New Zealand, Canada, Europe, Korea, Taiwan, and United States, respectively. In conclusion, the SRs of the VLBWIs and ELBWIs improved in the 2010s compared with those in the 2000s in Korea. This improvement is considered to have been related to the role of the KNN built in 2013. However, the latest VLBWI and ELBWI SRs in 2015 are still low compared with those in Japan, Australia and New Zealand, Canada, and Europe. In the future, we must establish and develop the tasks that are presented as future tasks in this review.