Neonatal Diabetes Mellitus Due to KCNJ11 (KIR6.2) Mutation Successfully Treated with Sulfonylurea

Neonatal diabetes mellitus (NDM) is a rare disease that occurs at less than 6 months of age and is presumably caused by a mutation in the gene that affects pancreatic beta-cell function. Approximately 80% of NDM cases reveal a known genetic mutation, and mutations in potassium inwardly rectifying channel subfamily J member 11 (KCNJ11) and ABCC8 affecting the pancreatic beta-cell adenosine triphosphate-sensitive potassium channel may be treated with oral sulfonylurea. Early recognition of mutations in KCNJ11 and ABCC8 is important because early administration of sulfonylurea can not only control blood glucose levels but also improve neurodevelopmental outcomes. In the present study, we report a case of NDM that initially presented as diabetic ketoacidosis at the age of 1 month, accompanied by seizures during hospitalization. After confirmation of the KCNJ11 gene mutation (c.989A>C), we started administering oral sulfonylurea (glimepiride) at the age of 2 months. After gradually increasing the dosage of glimepiride, insulin was discontinued at the age of 3 months. To date, the infant’s blood glucose levels have been well controlled without significant hypoglycemic events. No further episodes of seizures have occurred, and his developmental status is favorable.

Mortality and Morbidities according to Time of Birth in Extremely Low Birth Weight Infants

Background@#Although the overall quality of high-risk neonatal care has improved recently, there is still concern about a difference in the quality of care when comparing off-hour births and regular-hour births. Moreover, there are no data in Korea regarding the impact of time of birth on mortality and morbidities in preterm infants. @*Methods@#A total of 3,220 infants weighing < 1,000 g and born at 23–34 weeks in 2013–2017 were analyzed based on the Korean Neonatal Network data. Mortality and major morbidities were analyzed using logistic regression according to time of birth during off-hours (nighttime, weekend, and holiday) and regular hours. The institutes were sub-grouped into hospital group I and hospital group II based on the neonatal intensive care unit (NICU) care level defined by the mortality rates of < 50% and ≥ 50%, respectively, in infants born at 23–24 weeks' gestation. @*Results@#The number of births during regular hours and off-hours was similar. In the total population and hospital group I, off-hour births were not associated with increased neonatal mortality and morbidities. However, in hospital group II, increased early mortality was found in the off-hour births when compared to regular-hour births. @*Conclusion@#Efforts to improve the overall quality of NICU are required to lower the early mortality rate in off-hour births. Also, other sensitive indexes for the evaluation of quality of NICU care should be further studied.

Neonatal Diabetes Mellitus Due to KCNJ11 (KIR6.2) Mutation Successfully Treated with Sulfonylurea

Neonatal diabetes mellitus (NDM) is a rare disease that occurs at less than 6 months of age and is presumably caused by a mutation in the gene that affects pancreatic beta-cell function. Approximately 80% of NDM cases reveal a known genetic mutation, and mutations in potassium inwardly rectifying channel subfamily J member 11 (KCNJ11) and ABCC8 affecting the pancreatic beta-cell adenosine triphosphate-sensitive potassium channel may be treated with oral sulfonylurea. Early recognition of mutations in KCNJ11 and ABCC8 is important because early administration of sulfonylurea can not only control blood glucose levels but also improve neurodevelopmental outcomes. In the present study, we report a case of NDM that initially presented as diabetic ketoacidosis at the age of 1 month, accompanied by seizures during hospitalization. After confirmation of the KCNJ11 gene mutation (c.989A>C), we started administering oral sulfonylurea (glimepiride) at the age of 2 months. After gradually increasing the dosage of glimepiride, insulin was discontinued at the age of 3 months. To date, the infant’s blood glucose levels have been well controlled without significant hypoglycemic events. No further episodes of seizures have occurred, and his developmental status is favorable.

Mortality and Morbidities according to Time of Birth in Extremely Low Birth Weight Infants

Background@#Although the overall quality of high-risk neonatal care has improved recently, there is still concern about a difference in the quality of care when comparing off-hour births and regular-hour births. Moreover, there are no data in Korea regarding the impact of time of birth on mortality and morbidities in preterm infants. @*Methods@#A total of 3,220 infants weighing < 1,000 g and born at 23–34 weeks in 2013–2017 were analyzed based on the Korean Neonatal Network data. Mortality and major morbidities were analyzed using logistic regression according to time of birth during off-hours (nighttime, weekend, and holiday) and regular hours. The institutes were sub-grouped into hospital group I and hospital group II based on the neonatal intensive care unit (NICU) care level defined by the mortality rates of < 50% and ≥ 50%, respectively, in infants born at 23–24 weeks' gestation. @*Results@#The number of births during regular hours and off-hours was similar. In the total population and hospital group I, off-hour births were not associated with increased neonatal mortality and morbidities. However, in hospital group II, increased early mortality was found in the off-hour births when compared to regular-hour births. @*Conclusion@#Efforts to improve the overall quality of NICU are required to lower the early mortality rate in off-hour births. Also, other sensitive indexes for the evaluation of quality of NICU care should be further studied.

Comparison of Respiratory Outcomes between Less Invasive Surfactant Administration and the IntubationSurfactant-Extubation Technique in Premature Infants with Respiratory Distress Syndrome

Purpose@#To compare respiratory outcomes between less invasive surfactant admi nistration (LISA) and the intubation-surfactant-extubation (INSURE) technique in premature infants with respiratory distress syndrome (RDS). @*Methods@#We performed a retrospective medical chart review for 75 premature in fants who were born at a gestational age (GA) of ≤34 weeks (between January 2017 and December 2019) and developed RDS after birth. Data on the demographic and outcome variables, including respiratory outcomes, were collected and compared between the infants who received LISA and those who received INSURE as a rescue therapy for RDS. @*Results@#No signifcant differences in GA, birth weight, and other demographic characteristics were found between the LISA and INSURE groups (GA: 28.7 weeks vs.28.8 weeks, P=0.449; birth weight: 1,236 g vs. 1,124 g, P=0.714). At the delivery room, although the infants showed no significant difference in positive pressure ventilation rate after birth, the LISA group showed a higher rate of continuous positive airway pressure application than the INSURE group. The infants in the LISA group presented a higher risk of requiring multiple doses of surfactant for RDS than the infants in the INSURE group (57% vs. 17.5%, P=0.001). However, the duration of invasive and/ or noninvasive respiratory support and incidence of bronchopulmonary dysplasia showed no signifciant difference between the two groups. @*Conclusion@#In the present study, no significant differences in the incidence of inhospital respiratory outcomes such as bronchopulmonary dysplasia were found between the LISA and INSURE groups. These results suggest that LISA can be an alternative therapeutic option for treating RDS to avoid intubation and mechanica ventilation in premature infants.

Sedation for Brain Magnetic Resonance Imaging in Preterm Infants: Using Propofol under Anesthesiologist Supervision

Purpose@#We aimed to compare two different sedation protocols for brain magnetic resonance imaging (MRI) in preterm infants. One protocol used chloral hydrate (CH) with monitoring conducted by non-anesthesiologists, and the other used a continuous infusion of propofol (PF) with monitoring by anesthesiologists. @*Methods@#A total of 250 preterm infants born between January 2011 and December 2015 who received brain MRI during hospitalization in our neonatal intensive care unit (NICU) were included in this retrospective study. In period 1, sedation for brain MRI was done using a single dose or multiple doses of CH with monitoring conducted by NICU medical staff. In period 2, an anesthesiologist prescribed a continuous infu­sion of PF and titrated the dosage for minimal and adequate sedation. Data on the adverse events, including desaturation and bradycardia, were collected and compared between periods 1 and 2. @*Results@#Despite similar gestational ages of the patients in periods 1 and 2, the infants in period 1 showed a higher risk of developing bradycardia after sedation compared to those in period 2 (30.2% vs. 14.8%; an adjusted odds ratio of 2.35; 95% confidence interval of 1.12 to 4.91). Infants who had an adverse event after sedation had a lower gestational age and corrected age at the time of MRI (26.8 weeks vs. 27.9 weeks, P=0.004; 37.3 weeks vs. 38.3 weeks, P=0.023). The duration of MRI was significantly longer in infants that had an adverse event than those that did not (70.9 minutes vs.64.3 minutes). After adju­sting for various clinical factors, lower gestational age, lower corrected age at the time of MRI, and period 1 increased the risk of developing adverse events after sedation for MRI. @*Conclusion@#The use of a continuous PF infusion with dose titration and monitoring by an anesthesiologist is safe and feasible as a sedation protocol for brain MRI in prematurely born infants.

Communicating Bronchopulmonary Foregut Malformation Type III with Pulmonary Sequestration Diagnosed in a Newborn: A Case Report

Communicating bronchopulmonary foregut malformation (CBPFM) is a communication between the respiratory and gastrointestinal tracts that can be difficult to differentiate from pulmonary sequestration or H-type tracheoesophageal fistula (TEF) because of the similarities in clinical features. A female neonate born at full term had been experiencing respiratory difficulty during feeding from the third day of life. The esophagography performed to rule out H-type TEF revealed that the esophageal bronchus directly communicated with the left lower lobe (LLL) of the lung. Lobectomy of the LLL, fistulectomy of the esophagobronchial fistula, and primary repair of the esophagus were performed. Finally, CBPFM type III with pulmonary sequestration was confirmed on the basis of the postoperative histopathological finding. We report the first newborn case of CBPFM type III with pulmonary sequestration in Korea.

A Rare Case of Lethal Prenatal-Onset Infantile Cortical Hyperostosis

Infantile cortical hyperostosis, or Caffey's disease, usually presents with typical radiological features of soft tissue swelling and cortical thickening of the underlying bone. The disease can be fatal when it presents antenatally, especially before a gestational age of 35 weeks. This fatal, premature form of the disease is known to occur in various ethnic groups around the globe, and approximately 30 cases have been reported in English literature. This paper is unique in that it is the first paper to report a lethal form of prenatal-type infantile cortical hyperostosis diagnosed in South Korea. Born at gestational age of 27 weeks and 4 days, the patient had typical features of polyhydramnios, anasarca, hyperostosis of multiple bones, micrognathia, pulmonary hypoplasia, and hepatomegaly. The patient was hypotonic, and due to pulmonary hypoplasia and persistent pulmonary hypertension, had to be supported with high frequency ventilation throughout the entire hospital course. Due to the disease entity itself, as well as prolonged parenteral nutrition, liver failure progressed, and the patient expired on day 38 when uncontrolled septic shock was superimposed. The chromosome karyotype of the patient was normal, 46, XX, and COL1A1 gene mutation was not detected.

The Impact of Surgical Intervention on Neurodevelopmental Outcomes in Very Low Birth Weight Infants: a Nationwide Cohort Study in Korea

BACKGROUND: To investigate the incidence of surgical intervention in very low birth weight (VLBW) infants and the impact of surgery on neurodevelopmental outcomes at corrected ages (CAs) of 18–24 months, using data from the Korean Neonatal Network (KNN). METHODS: Data from 7,885 VLBW infants who were born and registered with the KNN between 2013 to 2016 were analyzed in this study. The incidences of various surgical interventions and related morbidities were analyzed. Long-term neurodevelopmental outcomes at CAs of 18–24 months were compared between infants (born during 2013 to 2015, n = 3,777) with and without surgery. RESULTS: A total of 1,509 out of 7,885 (19.1%) infants received surgical interventions during neonatal intensive care unit (NICU) hospitalization. Surgical ligation of patent ductus arteriosus (n = 840) was most frequently performed, followed by laser therapy for retinopathy of prematurity and laparotomy due to intestinal perforation. Infants who underwent surgery had higher mortality rates and greater neurodevelopmental impairment than infants who did not undergo surgery (P value < 0.01, both). On multivariate analysis, single or multiple surgeries increased the risk of neurodevelopmental impairment compared to no surgery with adjusted odds ratios (ORs) of 1.6 with 95% confidence interval (CI) of 1.1–2.6 and 2.3 with 95% CI of 1.1–4.9. CONCLUSION: Approximately one fifth of VLBW infants underwent one or more surgical interventions during NICU hospitalization. The impact of surgical intervention on long-term neurodevelopmental outcomes was sustained over a follow-up of CA 18–24 months. Infants with multiple surgeries had an increased risk of neurodevelopmental impairment compared to infants with single surgeries or no surgeries after adjustment for possible confounders.

Continuous Renal Replacement Therapy in Preterm Infants

PURPOSE: Despite the increasing use of continuous renal replacement therapy (CRRT) in the neonatal intensive care unit (NICU), few studies have investigated its use in preterm infants. This study evaluated the prognosis of preterm infants after CRRT and identified risk factors of mortality after CRRT. MATERIALS AND METHODS: A retrospective review was performed in 33 preterm infants who underwent CRRT at the NICU of Samsung Medical Center between 2008 and 2017. Data of the demographic characteristics, predisposing morbidity, cardiopulmonary function, and CRRT were collected and compared between surviving and non-surviving preterm infants treated with CRRT. Univariable and multivariable analyses were performed to identify factors affecting mortality. RESULTS: Compared with the survivors, the non-survivors showed younger gestational age (29.3 vs. 33.6 weeks), lower birth weight (1359 vs. 2174 g), and lower Apgar scores at 1 minute (4.4 vs. 6.6) and 5 minutes (6.5 vs. 8.6). At the initiation of CRRT, the non-survivors showed a higher incidence of inotropic use (93% vs. 40%, p=0.017) and fluid overload (16.8% vs. 4.0%, p=0.031). Multivariable analysis revealed that fluid overload >10% at CRRT initiation was the primary determinant of mortality after CRRT in premature infants, with an adjusted odds ratio of 14.6 and a 95% confidence interval of 1.10–211.29. CONCLUSION: Our data suggest that the degree of immaturity, cardiopulmonary instability, and fluid overload affect the prognosis of preterm infants after CRRT. Preventing fluid overload and earlier initiation of CRRT may improve treatment outcomes.

Tolerability and Effect of Early High-Dose Amino Acid Administration in Extremely Low Birth Weight Infants

PURPOSE: The aim of this study is to examine the tolerability and effect of early highdose amino acid administration in extremely low birth weight infants (ELBWIs). METHODS: This retrospective cohort study included ELBWI (birth weight < 1,000 g, n=142). Biochemical, nutritional, and neurodevelopmental data were compared between infants who received conventional low amino acid (LAA; 1.5 g/kg/day) and those who received high amino acid (HAA; 3 g/kg/day) within the first 48 hours after birth. Neurodevelopmental data included weight, height, and head circumference at discharge, 12 to 14 and 18 to 24 months of corrected age and the Korean Bayley Scale of Infant Development II (K-BSID-II) score at 18 to 24 months of corrected age. RESULTS: The HAA group demonstrated higher peak plasma albumin (3.0±0.4 vs. 3.2±0.5, P < 0.05) and lower serum creatinine (1.7±0.9 vs. 1.4±0.8, P < 0.05) during the first 14 days than the LAA group. Full enteral feeding was achieved significantly earlier in infants in the HAA group than in infants in the LAA group (46.2±23.0 days vs. 34.3±21 days, P < 0.01). There was no difference between the two groups in the z score changes in all growth indicators from birth to discharge and at 12 to 14 and 18 to 24 months of corrected age, as well as in the K-BSID-II score at 18 to 24 months of corrected age. CONCLUSION: Aggressive administration of amino acids during the first 2 days of life in ELBWI was well tolerated and correlated with earlier full enteral feeding, but did not improve growth and neurodevelopment.

The Youngest Survivor with Gestational Age of 21(5/7) Weeks

The decision whether or not to resuscitate extremely low gestational age (GA) infants is recommended to be individualized according to antenatal counseling with parents, neonatologists, and obstetricians. A GA of 22(0/7)–23(6/7) weeks is generally considered as the lower end of the range where infants can be candidates for selective resuscitation. Below this lower end of periviable gestation, resuscitation is usually not considered and survivors are rarely reported. To date, the youngest survivor is an infant with a GA of 21(6/7) weeks reported in the English medical literature. Here, we report the case of a female infant, the first twin conceived through in vitro fertilization, with a GA of 21(5/7) weeks, who was resuscitated initially according to strong parental wishes after antenatal counseling and is still surviving at 43 months of age with fairly good neurodevelopmental outcome.

Comparison of Safety of Sedatives Versus General Anesthesia in Laser Therapy for Retinopathy of Prematurity

PURPOSE: Laser therapy for retinopathy of prematurity (ROP) is commonly performed under general anesthesia (GA). However, the use of GA for laser therapy in neonates who have already undergone invasive ventilation may lead to postoperative complications such as severe apnea or the development of ventilator dependency. This study aimed to examine the safety of administering only sedatives instead of GA in extremely low birth weight (ELBW) infants, who are the usual recipients of laser therapy for ROP. METHODS: Among ELBW infants who were admitted to the neonatal intensive care unit (NICU) at Samsung Medical Center between January and December 2012, we studied 30 patients treated with laser therapy for ROP. RESULTS: The mean gestational age of the patients was 24.6±1.9 weeks, with a mean birth weight of 646±140 g. The mean age and weight of patients at the time of laser therapy for ROP was 36.3±2.3 weeks and 1,470±423 g. In terms of sedatives, 14 patients (46.7%) were administered chloral hydrate alone, 14 (46.7%) were administered a combination of chloral hydrate and midazolam, one was administered midazolam alone, and one received fentanyl. Prior to laser therapy, 16 patients (53.5%) had established self-respiration, 13 (43.3%) relied on non-invasive ventilation and one patient relied on invasive mechanical ventilation. Following laser therapy, two patients who initially had exhibited self-respiration required respiratory assistance via non-invasive positive pressure ventilation and no patient required intratracheal intubation. CONCLUSIONS: We conclude that the use of sedatives may be safe for ELBW infants who undergo laser therapy for ROP.

Novel Pathogenic Variant (c.580C>T) in the CPS1 Gene in a Newborn With Carbamoyl Phosphate Synthetase 1 Deficiency Identified by Whole Exome Sequencing

Diagnosis of the urea cycle disorder (USD) carbamoyl-phosphate synthetase 1 (CPS1) deficiency (CPS1D) based on only the measurements of biochemical intermediary metabolites is not sufficient to properly exclude other UCDs with similar symptoms. We report the first Korean CPS1D patient using whole exome sequencing (WES). A four-day-old female neonate presented with respiratory failure due to severe metabolic encephalopathy with hyperammonemia (1,690 µmol/L; reference range, 11.2-48.2 µmol/L). Plasma amino acid analysis revealed markedly elevated levels of alanine (2,923 µmol/L; reference range, 131-710 µmol/L) and glutamine (5,777 µmol/L; reference range, 376-709 µmol/L), whereas that of citrulline was decreased (2 µmol/L; reference range, 10-45 µmol/L). WES revealed compound heterozygous pathogenic variants in the CPS1 gene: one novel nonsense pathogenic variant of c.580C>T (p.Gln194*) and one known pathogenic frameshift pathogenic variant of c.1547delG (p.Gly516Alafs*5), which was previously reported in Japanese patients with CPS1D. We successfully applied WES to molecularly diagnose the first Korean patient with CPS1D in a clinical setting. This result supports the clinical applicability of WES for cost-effective molecular diagnosis of UCDs.

Discordant Congenital Cytomegalovirus Infection in Twins

Cytomegalovirus (CMV) infection is one of the most common congenital infections. The first case of discordant congenital CMV infection in twins occurred in Korea. A 31-year-old woman became pregnant with twins (dichorionic-diamniotic). An elective caesarean section was performed at 37 weeks. The first baby was male, weighing 2,410 g with an Apgar score of 8/9. The second baby was female, weighing 1,380 g with an Apgar score of 5/8. She had experienced intrauterine growth retardation, and presented with microcephaly, micrognathia, and joint stiffness. During the work-up for discordant twins, the second baby's serum test was positive for CMV immunoglobulin M. Her urine, blood, and cerebrospinal fluid (CSF) were CMV polymerase chain reaction positive. The first baby's CMV tests were negative. Ophthalmologic exam and audiometry performed on the second baby showed CMV retinitis and bilateral sensorineural hearing loss. She was treated with intravenous ganciclovir. Currently, she is bed-ridden and has significant developmental delay. Although the causes of discordant congenital CMV infection in twins are unclear, this case shows that discordant congenital CMV infection should be considered in twins with significant differences in intrauterine growth or clinical symptoms after birth.

Stem Cell Therapy for Neonatal Disorders: Prospects and Challenges

Despite recent advances in neonatal medicine, neonatal disorders, such as bronchopulmonary dysplasia and intraventricular hemorrhage in preterm neonates and hypoxic ischemic encephalopathy in term neonates, remain major causes of mortality and morbidities. Promising preclinical research results suggest that stem cell therapies represent the next breakthrough in the treatment of currently intractable and devastating neonatal disorders with complex multifactorial etiologies. This review focuses primarily on the potential role of stem cell therapy in the above mentioned neonatal disorders, highlighting the results of human clinical trials and the challenges that remain to be addressed for their safe and successful translation into clinical care of newborn infants.

Prophylactic versus Early Rescue Surfactant Treatment in Preterm Infants Born at Less than 30 Weeks Gestation or with Birth Weight Less than or Equal 1,250 Grams

Prophylactic surfactant is known to be effective to reduce chronic lung disease in preterm infants compared with rescue surfactant treatment. In Korea, early prophylactic surfactant therapy was introduced in 2011. However, recently, the increased utilization of antenatal steroids and early stabilization through continuous positive airway pressure (CPAP) in the delivery room may have changed the risks and benefits of prophylactic surfactant therapy of infants at high risk of respiratory distress syndrome (RDS). We compared the effects and safety of prophylactic surfactant therapy (within 30 minutes after birth) and early selective surfactant therapy (within 3 hours after birth) in preterm infants born at < 30 weeks gestation or with birth weight ≤ 1,250 g. The clinical data of 193 infants in period 1 (from 2008 to 2010, early selective surfactant therapy group) were collected retrospectively; those of 191 infants in period 2 (from 2012 to 2014, prophylactic surfactant therapy group) were collected prospectively. Compared to period 1, the rate of intubation and surfactant use were significantly increased in period 2. The use of multiple doses of surfactant in period 2 was significantly increased compared with period 1. Despite more invasive and aggressive management in period 2, there was no difference in the duration of mechanical ventilation, the incidence of bronchopulmonary dysplasia (BPD) or death, and the risk of other adverse neonatal outcomes between the 2 groups. In conclusion, the benefit of prophylactic surfactant therapy in infants treated under current practices is no longer clear compared to early selective surfactant therapy.

A Novel De Novo Pathogenic Variant in FOXF1 in a Newborn with Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is an autosomal dominant, fatal developmental disorder of the lungs, with a mortality rate of about 100%. ACD/MPV is caused by mutations in FOXF1. Herein, we describe a newborn boy with ACD/MPV carrying a novel pathogenic variant of FOXF1. The patient developed respiratory distress and severe pulmonary hypertension on the first day of life. Despite aggressive cardiorespiratory management, including veno-venous extracorporeal membrane oxygenation, his condition deteriorated rapidly, and he died within the first month of his life. Lung histology showed the characteristic features of ACD/MPV at autopsy. Sequence analysis of FOXF1 from genomic DNA obtained from autopsied lung tissue revealed that the patient was heterozygous for a novel missense variant (c.305T>C; p.Leu102Pro). Further analysis of both parents confirmed the de novo occurrence of the variant. To the best of our knowledge, this is the first report of genetically confirmed ACD/MPV in Korea.

MERS-CoV Infection in a Pregnant Woman in Korea

Middle East respiratory syndrome (MERS) is a lethal respiratory disease — caused by MERS-coronavirus (MERS-CoV) which was first identified in 2012. Especially, pregnant women can be expected as highly vulnerable candidates for this viral infection. In May 2015, this virus was spread in Korea and a pregnant woman was confirmed with positive result of MERS-CoV polymerase chain reaction (PCR). Her condition was improved only with conservative treatment. After a full recovery of MERS, the patient manifested abrupt vaginal bleeding with rupture of membrane. Under an impression of placenta abruption, an emergent cesarean section was performed. Our team performed many laboratory tests related to MERS-CoV and all results were negative. We report the first case of MERS-CoV infection during pregnancy occurred outside of the Middle East. Also, this case showed relatively benign maternal course which resulted in full recovery with subsequent healthy full-term delivery without MERS-CoV transmission.

Clinical Characteristics of Early Onset Sepsis in Micropreemie Born at 25 or Less than 25 Weeks of Gestational Age / 대한주산의학회잡지

PURPOSE: The aim of this study is to determine the clinical characteristics of early onset sepsis (EOS) in micropreemie. METHODS: We retrospectively reviewed medical records of 107 extremely preterm infants born at 25 or less than 25 weeks of gestation and admitted to the neonatal intensive care unit of Samsung Medical Center from January 2013 to August 2015. Infants were divided into two groups based on the presence of culture-proven EOS in the first 7 days of life. Retrospective analysis of perinatal factors and laboratory findings within the first week of life was done between two groups. We compared the neonatal outcomes among two groups. RESULTS: Culture-proven EOS was diagnosed in 11 of 107 infants (10.3%). Main pathogen of EOS was Staphylococcus epidermidis (45.5%). There were no significant differences between control group and EOS group in gestational age, birth weight, Apgar score, delivery type and pathologic chorioamnionitis. Among 11 infants with EOS, 9 showed fetal tachycardia (P=0.001). And EOS group presented lower platelet count at 3rd day and 7th day of life than that of control group (P=0.033, P=0.045). Neonatal outcomes in EOS group were compatible with control group. Main cause of death was sepsis in EOS group. CONCLUSION: In micropreemie, EOS is important factor of mortality. Our data suggest that fetal tachycardia and low platelet count during the first 7 days of life were associated with EOS.