Jae Woo Lim

The changing trends in live birth statistics in Korea, 1970 to 2010.

Although Korean population has been growing steadily during the past four decades, the nation is rapidly becoming an aging society because of its declining birth rate combined with an increasing life expectancy. In addition, Korea has one of the lowest fertility rates in the world due to fewer married couples, advanced maternal age, and falling birth rate. The prevalence of low birth weight infants and multiple births has been increased compared with the decrease in the birth rate. Moreover, the number of congenital anomalies is expected to increase due to the advanced maternal age. In addition, the number of interracial children is expected to increase due to the rise in the number of international marriages. However, the maternal education level is high, single-mother birth rate is low, and the gender imbalance has lessened. The number of overweight babies has been decreased, as more pregnant women are receiving adequate prenatal care. Compared to the Asian average birth weight, the average birth weight is the highest in Asia. Moreover, the rate of low birth weight infants is low, and infant mortality is similarly low across Asia. Using birth data from Statistics Korea and studies of birth outcomes in Korea and abroad, this study aimed to assess the changes in maternal and infant characteristics associated with birth outcomes during the past four decades and identify necessary information infrastructures to study countermeasures the decrease in birth rate and increase in low birth weight infants in Korea.

A Useful Predictor of Early Atherosclerosis in Obese Children: Serum High-sensitivity C-reactive Protein

Childhood obesity seems to contribute to the development of vascular inflammation and the progression of arterial wall changes. High-sensitivity C-reactive protein (hs-CRP) has recently emerged as a useful biomarker for vascular inflammation associated with atherosclerosis. The objectives of this study were to evaluate the association of the serum hs-CRP level with ultrasonic findings of early atherosclerosis, carotid intima-media wall thickness (IMT) and brachial flow-mediated dilation (FMD), in obese children. Thirty eight obese children and 45 sex/age-matched healthy control children were recruited. Serum CRP levels were measured by the high-sensitive latex turbidimetric immunoassay, and we measured carotid IMT and brachial FMD using high-resolution B-mode ultrasonography. Obese children had significantly higher hs-CRP levels (1.40±0.74 mg/L vs. 0.55±0.49 mg/L, p<0.01), as well as increased IMT (0.52±0.09 mm vs. 0.41±0.07 mm, p<0.01) and impaired FMD (7.35±7.78% vs. 20.34±16.81%, p<0.01) compared to healthy controls. Serum hs-CRP correlated positively with IMT (r=0.413, p<0.05) and inversely with FMD (r=-0.350, p<0.05) in the obesity group. Measurement of the serum hs-CRP level is a simple, cheap, and highly reproducible assay and correlates with IMT and FMD in obese children. Thus, it would be a useful marker for evaluating and estimating the degree of atherosclerosis in children.

Fecal calprotectin concentration in neonatal necrotizing enterocolitis

Purpose Among the many factors associated with acute intestinal mucosal infection, numerous studies have proposed the usefulness of fecal calprotectin. The aim of this study was to evaluate the usefulness of fecal calprotectin in the diagnosis of necrotizing enterocolitis (NEC). Methods We collected 154 stool samples from 16 very low birth weight and premature newborns at the Konyang University Hospital neonatal intensive care unit or neonatal nursery. The stool samples were collected using the Calprest device, and the fecal calprotectin level was measured with the BÜHLMANN Calprotectin enzyme-linked immunosorbent assay kit. Results Fecal calprotectin levels were significantly higher in the NEC group than in the non-NEC group (P=0.02). There was a significant positive linear relationship between the fecal calprotectin level and number of days after birth (P=0.00) in the gestational age <26 weeks group. There was a significant negative linear relationship between the calprotectin level and number of days after birth (P=0.03) in the gestational age ≥26 weeks and <30 weeks group. There was no difference in the calprotectin levels according to the type and method of feeding between the NEC and non-NEC groups. Conclusion Fecal calprotectin levels were significantly increased in premature infants with NEC. The fecal calprotectin test is a noninvasive, easy, and useful tool for the diagnosis of NEC.

Birth Outcomes of Koreans by Birthplace of Infants and Their Mothers, the United States versus Korea, 1995-2004

The acculturation effect of immigrant women on birth outcomes varies by race. We examined birth outcomes of three groups of births for the period 1995-2004, USA births to the USA-born Korean mothers, USA births to the non-USA-born Korean mothers, and births in Korea. In singleton USA births to both Korean parents, average birth weight was 3,294 g for the USA-born Korean mothers and 3,323 g for the non-USA-born Korean mothers. However, this difference was not significant, once controlled for other maternal sociodemographic, obstetric and medical factors. Low birth weight and prematurity prevalence were not different by maternal nativity between these two singleton groups. Average birth weight of all births including multiplets in Korea was 3,270 g, compared to 3,297 g for all USA-born infants including multiplets and births either to both or one Korean parents. This difference might have reflected a significantly lower educational attainment of mothers in Korea compared to Korean mothers in the USA. Low birth weight rate was consistently lower in infants born in Korea compared to the USA-born, but this difference became less, 4.2% and 4.6% respectively by 2004. These observations suggest that in the USA acculturation effect of Korean immigrants on birth outcomes is negligible.

Effect of early postnatal neutropenia in very low birth weight infants born to mothers with pregnancy-induced hypertension

Purpose In this study, we aimed to investigate the perinatal clinical conditions of very low birth weight (VLBW) infants born to mothers with pregnancy-induced hypertension (PIH) focusing on the effects of early postnatal neutropenia. Methods We reviewed the medical records of 191 VLBW infants who were born at Konyang University Hospital, between March 2003 and May 2011. We retrospectively analyzed the clinical characteristics of the infants and their mothers and compared the incidence of perinatal diseases and mortality of the infants according to the presence or absence of maternal PIH and neutropenia on the first postnatal day. Results Infants born to mothers with PIH showed an increased incidence of neutropenia on the first postnatal day (47.4%), cesarean delivery, and intrauterine growth restriction. When the infants born to mothers with PIH showed neutropenia on the first postnatal day, their incidence of respiratory distress syndrome (RDS) was increased (P=0.031); however, the difference was not found to be significant through logistic regression analysis. In all the VLBW infants, neutropenia on the first postnatal day was correlated with the development of RDS. The incidence of the other perinatal diseases involving sepsis and mortality did not significantly differ according to the presence or absence of neutropenia in infants born to mothers with PIH. Conclusion In VLBW infants born to mothers with PIH, the incidence of neutropenia on the first postnatal day was increased and it was not significantly correlated with the development of perinatal diseases involving RDS, sepsis, and mortality.

Risk Factors for Cause-specific Mortality of Very-Low-Birth-Weight Infants in the Korean Neonatal Network.

This study attempted to assess the risk factors for mortality of very-low-birth-weight (VLBW) infants in the neonatal intensive care unit (NICU, n=2,386). Using data from the Korean Neonatal Network, we investigated infants with birth weights <1,500 g and gestational ages (GAs) of 22-31 weeks born between January 2013 and June 2014. Cases were defined as death at NICU discharge. Controls were randomly selected from live VLBW infants and frequency matched to case subjects by GA. Relevant variables were compared between the cases (n=236) and controls (n=236) by Cox proportional hazards regression to determine their associations with cause-specific mortality (cardiorespiratory, neurologic, infection, gastrointestinal, and others). In a Cox regression analysis, cardiorespiratory death were associated with a foreign mother (hazard ratio, HR, 4.33; 95% confidence interval, CI, 2.08-9.02), multiple gestation (HR, 1.65; 95% CI, 1.07-2.54), small for gestational age (HR, 2.06; 95% CI, 1.25-3.41), male gender (HR, 1.69; 95% CI, 1.10-2.60), Apgar score ≤3 at 5 min (HR, 1.97; 95% CI, 1.18-3.31), and delivery room resuscitation (HR, 2.60; 95% CI, 1.53-4.40). An Apgar score ≤3 at 5 min was also associated with neurological death (HR, 2.95; 95% CI, 1.29-6.73). Death due to neonatal infection was associated with outborn delivery (HR, 5.09; 95% CI, 1.46-17.74). Antenatal steroid and preterm premature rupture of membranes reduced risk of cardiorespiratory death (HR, 0.43; 95% CI, 0.27-0.67) and gastrointestinal death (HR, 0.30; 95% CI, 0.13-0.70), respectively. In conclusion, foreign mother, multiple gestation, small gestation age, male gender, Apgar score ≤3 at 5 min, and resuscitation in the delivery room are associated with cardiorespiratory mortality of VLBW infants in NICU. An Apgar score ≤3 at 5 min and outborn status are associated with neurological and infection mortality, respectively.

The Association between Helicobacter pylori Infection and Body Weight among Children

Purpose We performed to reveal the association between the Helicobacter pylori infection and body weight among children. Methods Out retrospective study included patients who underwent the H. pylori immunoglobulin G testing at Konyang University Hospital between March 2011 and June 2014. These patients were classified as seropositive (28 boys, 27 girls; mean age: 9.89±3.28 years) or seronegative (55 boys, 54 girls; mean age: 9.84±3.02 years). Next, we compared various characteristics between the seropositive and negative groups, as well as between obese children (body weight ≥90th percentile) and non-obese children (body weight <90th percentile). Furthermore, we compared the change in body weight after 2 months of treatment with amoxicillin, clarithromycin and omeprazole among the 55 seropositive children (14 treated children and 41 non-treated children). Results There were no differences in the weights and laboratory data for the 55 seropositive children and 109 seronegative children (weight; 40.96±18.11 kg vs. 36.85±13.72 kg, respectively; p=0.14). And, there was no difference in the prevalence of H. pylori infection among the 29 obese and 135 non-obese children (p=0.581). However, after 2 months of eradication, the 14 treated patients exhibited a significant weight gain (+0.91±0.52 kg), compared to the 41 non-treated patients (-0.29±1.16 kg, p=0.025). Conclusion Our findings present that obesity was not associated with the H. pylori infection, although H. pylori eradication led to significant increase in body weight.

Increase in Aminotransferase Levels during Urinary Tract Infections in Children

Purpose The aim of this study was to evaluate the prevalence of increased aminotransferase levels and to identify associated factors in children admitted to hospital with urinary tract infections (UTIs). Methods The study included children with a diagnosis of UTI who were admitted to the Konyang University Hospital from January 2007 to May 2011. The total number of patients was 249 and the mean age was 15.88±28.21 months. UTI was defined as a positive urine culture (>105/colony forming unit [CFU]) with pyrexia. Patients were treated by intravenous antibiotics, such as ampicillin/sulbactam, aminoglycoside, cephalosporins or vancomycin. Patients with neonatal jaundice or other liver disease were excluded. We investigated the relationship of aminotransferase levels with the type of antibiotic, degree of vesicoureteral reflux (VUR), and causative organisms. Results Children with increased aminotransferase levels were younger than those with normal levels (p=0.001), but white blood cell count, platelet count, causative organisms, type of antibiotics and presence of VUR were not associated with aminotransferase levels. Aminotransferase levels became normal within 1 month after discharge without special measures, except in 1 case. Conclusion We found that many children with UTI have abnormal aminotransferase levels. In most cases, this change is mild and self-limiting. We conclude that increased aminotransferase level increase during UTI do not require unnecessary tests and excessive treatment.

A pediatric case of Bickerstaff's brainstem encephalitis

Bickerstaffs brainstem encephalitis is characterized by ophthalmoplegia, ataxia, and disturbance of consciousness. It is similar to Miller Fisher syndrome, a variant of Guillain-Barre syndrome, in that they share features such as ophthalmoplegia and ataxia. The difference is that patients with Bickerstaffs brainstem encephalitis have impaired consciousness, whereas patients with Miller Fisher syndrome have alert consciousness and areflexia. Here, we report the case of a 3-year-old child who was diagnosed with Bickerstaffs brainstem encephalitis presenting typical clinical features and interesting radiological findings. The patient showed ophthalmoplegia, ataxia, and subsequent stuporous mentality. Brain magnetic resonance imaging revealed high signal intensity in the pons and cerebellum around the 4th ventricle on a T2-weighted image. He was successfully treated with intravenous immunoglobulin. Differentiation of Bickerstaffs brainstem encephalitis and Miller Fisher syndrome is often difficult because they possess many overlapping features. Brain magnetic resonance imaging may be helpful in diagnosing Bickerstaffs brainstem encephalitis, especially when lesions are definitely found.

The Relationships between Respiratory Virus Infection and Aminotransferase in Children

Purpose We sought to examine the relationship between the clinical manifestations of nonspecific reactive hepatitis and respiratory virus infection in pediatric patients. Methods Patients admitted to the pediatric unit of Konyang University Hospital for lower respiratory tract disease between January 1, 2014 and December 31, 2014 and who underwent reverse transcriptase polymerase chain reaction tests were examined. The patients were divided into those with increased levels of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) and those with normal ALT or AST levels. Further, patients with increased ALT and AST levels were individually compared with patients in the normal group, and the blood test results were compared according to the type of respiratory virus. Results Patients with increased ALT or AST levels had one more day of hospital stay, on average, compared with patients in the normal group (5.3±3.1 days vs. 4.4±3.0 days, p=0.019). Patients in the increased ALT level group were younger and had a longer mean hospital stay, compared with patients in the normal group (p=0.022 and 0.003, respectively). The incidences of increased ALT or AST were the highest in adenovirus infections (6/24, 25.0%), followed by enterovirus (2/11, 18.2%) and respiratory syncytial virus A (21/131, 16.0%) infections. Conclusion Nonspecific reactive hepatitis is more common among patients with adenovirus, enterovirus and respiratory syncytial virus infection, as well as among those infected at a younger age. Compared with AST levels, ALT levels are better indicators of the severity of nonspecific reactive hepatitis.