Search

The long-term follow-up of lung function (LF) in extremely preterm (EP) infants with bronchopulmonary dysplasia (BPD) has shown a worldwide increase in small airway obstructions (SAO).We investigated the relationships between intrauterine Ureplasma infection in EP infants and bubbly/cystic lung, BPD, and SAO at school age.Placental pathology, placental Ureaplasma DNA (pU-DNA), and cord blood immunoglobulin M (IgM) (C-IgM) were investigated in 360 EP infants born from 1981 to 2004. Maternal amniotic inflammatory response (M-AIR) scores and hemosiderin deposition (HD) were estimated in the chorioamnion. The study subjects were divided into groups based on their M-AIR scores. Their LF at school age was compared with those of 33 healthy siblings.pU-DNA and C-IgM were significantly related to SAO at school age (p 0.012). M-AIR score 3 and pU-DNA1000 units had an odds ratio (OR) of 35 (95% confidence interval: 10-172) and 18 (5.6-67) for bubbly/cystic lung, and 11 (3.1 - 43) and 31 (4.5-349) for severe BPD, and 5.3 (2.1-11) and 12 (2.4-74) for SAO, respectively. The ORs of surfactant treatment, BPD grade III, OOur long-term cohort study of LF in EP infants revealed that intrauterine Ureaplasma was associated with bubbly/cystic lung, severe BPD, and SAO at school age.

OBJECTIVES To assess lung function and long-term respiratory outcomes in extremely low birth weight (ELBW) survivors. WORKING HYPOTHESIS ELBW, especially with respiratory complications in the neonatal period, affects lung function at a later age. STUDY DESIGN Longitudinal retrospective study. PATIENT-SUBJECT SELECTION Lung function was evaluated in 89 ELBW survivors (at ages 8 and 12) with or without a history of bronchopulmonary dysplasia (BPD) or a bubbly/cystic lung appearance in the neonatal period. METHODOLOGY FVC, FEV1, FEF50, and FEF75 were measured using spirometry. Two-way repeated-measures ANOVA was used to compare lung function and deterioration time course from 8 to 12 years of age. RESULTS Lung function variables were significantly and positively correlated between 8 and 12 years: %FVC (R2 = 0.558), %FEV1 (R2 = 0.539), %FEF50 (R2 = 0.412), and %FEF75 (R2 = 0.429). Lung function values were lower than Japanese reference values, especially in children with a history of severe BPD or a bubbly/cystic appearance. %FEV1 and FEV1/FVC ratio worsened from 8 to 12 years of age: 83.0 ± 17.0% versus 76.6 ± 17.8% (mean difference, 95%CI: −6.43, −9.10 to −3.75) and 84.0 ± 10.1% versus 78.2 ± 13.4% (mean difference, 95%CI: −5.82, −8.56 to −3.08), regardless of whether or not there was a history of neonatal respiratory disease. CONCLUSIONS In ELBW survivors, the obstructive pattern of lung function impairment deteriorated from 8 to 12 years of age, independent of the presence of severe BPD or bubbly/cystic appearance in the neonatal period.

Objective The aim of this study is to compare patent ductus arteriosus (PDA) management strategies and outcomes between the Neonatal Research Network of Japan (NRNJ) with proactive functional echocardiography and the Canadian Neonatal Network (CNN) with selective conventional echocardiography practice. Study Design Retrospective analyses examined very low-birth-weight infants admitted to the NRNJ or CNN in 2006 to 2008. Multivariable logistic regression analyses compared a composite outcome indicating a mortality or major morbidity (severe intraventricular hemorrhage, periventricular leukomalacia, severe retinopathy of prematurity, bronchopulmonary dysplasia, or necrotizing enterocolitis) between networks, according to PDA diagnosis and treatment, and tested the association between PDA treatment and the composite outcome within networks. Results PDA treatment (NRNJ:CNN) with conservative management (8%:16%), indomethacin only (77%:59%), ligation only (1%:13%), or indomethacin and ligation (14%:13%) varied significantly between networks. The composite outcome was lower in NRNJ versus CNN only among infants with PDA (odds ratio: 0.70; 95% confidence interval: 0.62–0.80). Surgical ligation was associated with higher composite outcome only in CNN (odds ratio: 1.79; 95% confidence interval: 1.40–2.28). Conclusion Lower composite mortality/morbidity outcome in Japan versus Canada only among infants with PDA, and association of surgical ligation with higher mortality/morbidity only in Canada, suggest differential PDA management and ligation processes contribute to outcome variation.

Wilson-Mikity syndrome (WMS) was first reported in 1960 by Wilson and Mikity. They described preterm infants who developed areas of cystic emphysema in the first month of life with subsequent progression to chronic lung disease (CLD) of infancy, although these infants did not exhibit early respiratory distress, such as respiratory distress syndrome (RDS). This condition was widely accepted over the next 20 years, but WMS is now rarely mentioned and is commonly considered an anachronism. In Japan, CLD is classified into six types according to the presence of RDS and/or intrauterine inflammation and appearance on chest X-ray. One type of CLD (type III, which accounts for 13.5% of all CLD) is defined as history of intrauterine inflammation and the typical bubbly and cystic appearance on chest X-ray described in the original report of WMS. There is insufficient evidence to determine whether WMS exists or whether WMS is relatively common only in Japan and not in other countries. It is important, however, to distinguish this type of CLD from other types because the strategy for the prevention or treatment of CLD should be different according to its origin, cause, and risk factors.

Aim Methods to improve the mental development of extremely low birthweight (ELBW) children are currently lacking. We assessed the effects of long-term supplementation of alpha-tocopherol on the neurological development of 259 school-aged ELBW children. Methods Extremely low birthweight participants were divided into three groups: group A with no alpha-tocopherol supplementation (n = 121); group B with the supplementation for

Objective: This study aimed to re-evaluate the effectiveness of antenatal corticosteroids (ACS) and to analyze the association between ACS and the mode of delivery in the context of perinatal morbidity and mortality in very-low-birth-weight (VLBW) infants. Study Design: This retrospective cohort study involved 15,765 VLBW infants born between 2003 and 2008 at less than 34 weeks of gestation and weighing less than 1,500 g at birth. Data were obtained from the Japanese neonatal research network database. Univariate and multivariate logistic regression analyses were performed to evaluate the impact of ACS and mode of delivery on the risk of infant mortality and morbidity. Results: Administration of ACS was associated with decreases in mortality rate, intraventricular hemorrhage (IVH) and retinopathy of prematurity (ROP), and was not associated with the incidence of respiratory distress syndrome (RDS), periventricular leukomalacia or necrotizing enterocolitis (NEC). When the administration of ACS was analyzed in the context of different modes of delivery, the incidence of IVH and ROP tended to decrease with cesarean section deliveries, whereas the incidence of RDS tended to decrease and the incidence of NEC tended to increase for infants delivered vaginally. The incidence of chronic lung disease tended to increase in association with both delivery methods. Conclusions: This large cohort study reconfirms that ACS treatment is associated with decreases in infant mortality and severe morbidity. Furthermore, the delivery method may be associated with severe morbidity in VLBW infants exposed to ACS.

OBJECTIVE: To provide instructive information on death and neurodevelopmental outcomes of infants born at 22 and 23 weeks’ gestational age. METHODS: The study cohort consisted of 1057 infants born at 22 to 25 weeks in the Neonatal Research Network, Japan. Neurodevelopmental impairment (NDI) at 36 to 42 months’ chronological age was defined as any of the following: cerebral palsy, hearing impairment, visual impairment, and a developmental quotient RESULTS: Numbers and incidences (%) of infants with death or NDI were 60 (80%) at 22 weeks and 156 (64%) at 23 weeks. In logistic regression analysis, gestational ages of 22 weeks (odds ratio [OR]: 5.40; 95% confidence interval [CI]: 2.48–11.76) and 23 weeks (OR: 2.14; 95% CI: 1.38–3.32) were associated with increased risk of death or NDI compared with 24 weeks, but a gestational age of 25 weeks (OR: 0.65; 95% CI: 0.45–0.95) was associated with decreased risk of death or NDI. In the systematic review, the medians (range) of the incidence of death or NDI in 8 cohorts were 99% (90%–100%) at 22 weeks and 98% (67%–100%) at 23 weeks. CONCLUSIONS: Infants born at 22 and 23 weeks’ gestation were at higher risk of death or NDI than infants at born at 24 weeks. However, outcomes were improved compared with those in previous studies. There is a need for additional discussions on interventions for infants born at 22 or 23 weeks’ gestation.

Aim The study aims to determine the risk factors associated with mortality and necrotising enterocolitis (NEC) among very low birthweight infants in 95 neonatal intensive care units in the Asian Network on Maternal and Newborn Health. Methods This is a cross-sectional study using an international collaborative database of 17 595 very low birthweight infants admitted within 28 days of birth between 2003 and 2006 in four Asian countries. Information on the mortality and morbidity of neonates admitted to the neonatal intensive care units was recorded. Factors associated with the death and diseases of infants were estimated using multilevel multivariate logistic regression. Random effects were included to account for the clustering of the observations. Results Overall discharge mortality was 15% and it was significantly different by countries and units. The mortality rate was found to be significantly higher in neonates with pulmonary haemorrhage (odds ratio 1.83, 95% confidence interval 1.63–2.04) and air leak syndrome (odds ratio 1.51, 95% confidence interval 1.30–1.72). The incidence of NEC was 4.3% and was strongly associated with other morbidities. Multivariate logistic regression showed that patent ductus arteriosus was the most significant risk factor associated with NEC. Conclusions Our analysis has highlighted the great potential that multi-country, collaborative datasets have in terms of epidemiologic research when it comes to identifying issues in perinatal health that are common throughout Asia, and in relation to particular issues pertaining to specific countries and neonatal units. Establishing collaborative networks, conducting analyses of common datasets and further epidemiologic research are now essential measures to improve newborn health in Asia.

Background: The aim of the present study was to explore the relationships among neonatal morbidity, interventions and death or adverse neurodevelopmental outcomes in very low-birthweight (VLBW) infants. Methods: Subjects were infants with birthweight ≤1500 g who were cared for in the tertiary neonatal intensive care units in Japan. Multiple logistic regression analysis was performed to examine the odds ratios (OR) and 95% confidence intervals (CI) of neonatal factors for death or cerebral palsy (CP) and death or developmental delay (developmental quotient

Background: A nationwide survey on neonatal surgery conducted by the Japanese Society of Pediatric Surgeons has demonstrated that the mortality of neonatal intestinal perforation has risen over the past 15 years. The incidence of intestinal perforation in extremely low-birthweight (ELBW) neonates has been increasing as more ELBW neonates survive and as the live-birth rate of ELBW has increased. In contrast to necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP), the pathogenesis of meconium-related ileus, defined as functional bowel obstruction characterized by delayed meconium excretion and microcolon, remains unclarified. Methods: The histology of 13 ELBW neonates with intestinal perforation secondary to meconium-related ileus was reviewed, and the radiology of 33 cases of meconium-related ileus diagnosed on contrast enema was reviewed. Specimens obtained from 16 ELBW neonates without gastrointestinal disease served as age-matched controls for histological assessment. Results: The size of the ganglion cell nucleus in meconium-related ileus and in control subjects was 47.3 ± 22.0 µm2 and 37.8 ± 11.6 µm2, respectively, which was not significantly different. In all cases of meconium-related ileus, contrast enema demonstrated a microcolon or small-sized colon, with a gradual caliber change in the ileum and filling defects due to meconium in the ileum or colon, showing not-identical locations of caliber changes and filling defects. Conclusion: Morphological immaturity of ganglia was not suggested to be the pathogenesis of meconium-related ileus. Impaction of inspissated meconium is not the cause of obstruction, but the result of excessive water absorption in the hypoperistaltic bowel before birth, although the underlying mechanism responsible for the fetal hypoperistalsis remains unclear.

Background: The aim of this study was to describe and compare neurodevelopmental outcomes with birthweight (BW) groups at 250-g intervals of very-low-birthweight (VLBW) infants at 3 years of age in a multicenter cohort in Japan. Methods: A total of 3104 VLBW infants born in 2003 and 2004 registered in a NICU-network database were followed in the study. Neurodevelopmental impairment (NDI) was defined as any of the following impairments: cerebral palsy, unilateral or bilateral blindness, severe hearing impairment, or developmental delay; a developmental quotient (DQ)

Background: Neonatal anthropometric charts of the distribution of measurements, mainly birth weight, taken at different gestational ages are widely used by obstetricians and pediatricians. However, the relationship between delivery mode and neonatal anthropometric data has not been investigated in Japan or other countries.Methods: The subjects were selected from the registration database of the Japan Society of Obstetrics and Gynecology (2003–2005). Tenth centile, median, and 90th centile of birth weight by sex, birth order, and delivery mode were observed by gestational age from 22 to 42 weeks among eligible singleton births.Results: After excluding 248 outliers and 5243 births that did not satisfy the inclusion criteria, 144 980 births were included in the analysis. The distribution of 10th centile curves was skewed toward lower birth weights during the preterm period among both first live births and second and later live births delivered by cesarean section. More than 40% of both male and female live births were delivered by cesarean section at 37 weeks or earlier.Conclusions: The large proportion of cesarean sections influenced the skewness of the birth weight distribution in the preterm period.

OBJECTIVE. Our goal was to investigate the neonatal mortality rate and the mortality rate during the NICU stay for extremely low birth weight infants born in Japan in 2005. METHODS. The Committee of Neonatal Medicine of the Japan Pediatric Society retrospectively surveyed the deaths of extremely low birth weight infants born and hospitalized between January 1 and December 31, 2005. From 297 institutions in Japan, data on 3065 extremely low birth weight infants, which represented 98.4% of those reported in the maternal and health statistics of Japan in 2005, were collected. RESULTS. The neonatal mortality rate and the mortality rate during the NICU stay were 13.0% and 17.0%, respectively, which were lower than 17.7% and 21.5% in the survey in 2000. The neonatal mortality rates and the mortality rates during the NICU stay were 53.3% and 67.7% in the CONCLUSION. The mortality rates of extremely low birth weight infants who were born in 2005 demonstrated definite improvement.

Fretting fatigue tests for Ti–6Al–4 V alloy were conducted by use of the plate fatigue specimen with bolt-tightened shoe on both sides of the plate. It was clarified that the repeated bending stress at the contact area where fretting fatigue failure starts linearly decreased as stress over the contact area increased. Fretting fatigue crack starts from the pit where stress concentrate. The pit initiates when fretting debris were removed from the surface striation formed due to the contact slip movement. The fretting fatigue crack initiation mode was transgranular, while the fretting fatigue crack propagation mode was striation.

Background: The aim of the present study was to examine the presence of motilin in the duodenal epithelial cells of premature infants of

Objective. Evaluation of the placenta provides some important insights into pathophysiologic changes that take place during the prenatal and intrapartum process. We investigated the relationship between placental findings and periventricular leukomalacia (PVL) to obtain a better understanding of its cause.Methods. Thirty-two preterm infants with PVL delivered before 34 weeks’ gestation, between 1990 and 1999, were classified into 4 groups according to the onset of brain injury assumed from ultrasonographic presentation and clinical course: 2 Antenatal, 22 Peripartum, 5 Postnatal, and 3 in an unknown time of onset group. We evaluated the gross and histopathologic features of the placentas of each group and compared them with those of a control group matched by birth weight and gestational age in terms of the frequency of major placental findings. Potential confounding factors were controlled in logistic regression analyses.Results. Gross lesions with disturbance of uteroplacental circulation, including massive retroplacental hematoma, extensive infarction or thrombosis, and marked basal or perivillous fibrin deposition, were observed more frequently in the Antenatal + Peripartum combined subgroup than in the controls (41.7% vs 13.7%). Placentas from the Antenatal + Peripartum subgroup also demonstrated a significantly higher frequency of ischemic changes in villi, based on histopathologic examination, as compared with the control group (54.2% vs 13.7%). These associations remained after adjustment for confounding factors in logistic regression analyses (odds ratio: 4.04, 95% confidence interval: 1.40–11.67; and odds ratio: 7.28, 95% confidence interval: 2.50–21.20; respectively). Frequencies of chorioamnionitis and twin placentation tended to be higher in PVL cases than in the controls, although the differences were not statistically significant (46.9% vs 37.9%, 37.5% vs 20.0%, respectively).Conclusions. These results suggest that disturbed placental circulation underlies the development of PVL in the majority of cases with prenatal and peripartum brain injury. In chorioamnionitis cases, certain additional factors were suggested in the genesis of PVL. Thus, placental examination is essential for elucidating the pathophysiologic changes leading to PVL in the perinatal process.

Background: There is a significant association between hepatoblastoma and low birthweight. A case-control study was conducted to reveal risk factors for hepatoblastoma in children of extremely low birthweight (

To evaluate the incidence of respiratory distress syndrome (RDS) in infants born to mothers with placenta previa and to assess the risk factors for RDS.Ninety-nine pregnant women with placenta previa who delivered by cesarean section at 30-35 weeks of gestation were compared retrospectively with 102 pregnant women matched for week of gestation and birth year, who underwent elective cesarean section. Maternal characteristics, neonatal outcome, and incidence of RDS were analyzed. Umbilical cord blood samples were collected at delivery and were used to determine cortisol, epinephrine, and norepinephrine levels. Student's t-test, the chi-square test, and Fisher's exact test were used for statistical comparisons. P0.05 was considered significant. The Mann-Whitney U test was used for comparison of continuous variables.Preeclampsia, histological chorioamnionitis, and premature rupture of membranes were significantly lower in the placenta previa group (placenta previa: 2.0% vs. control: 14.7%, P0.01; 14.1% vs. 30.1%, P0.01; 7.1% vs. 17.6%, P0.05, respectively). The incidence of RDS was significantly higher in the placenta previa group than in the control group (29.3% vs. 6.9%, P0.0001). The cortisol level in umbilical cord blood in the placenta previa group was lower than in the control group (median 7.3, range 4.4-14.9 microg/dl vs. median 10.6, range 4.9-30.3 microg/dl, P0.05). There were no significant differences in epinephrine or norepinephrine levels between the two groups.The incidence of RDS in infants delivered at 30-35 weeks' gestation by cesarean section was significantly higher in mothers with placenta previa than in women without placenta previa. This may reflect decreased fetal stress since the cord blood cortisol levels were found to be lower in women with placenta previa.

AIM—To investigate the colonisation with Bifidobacterium breve of the bowels of very low birthweight (VLBW) infants. METHODS—The adverse effects of B breve were examined in 66 VLBW infants (preliminary study). A prospective randomised clinical study of 91 VLBW infants was also completed and these infants were followed up for three years. Precise viable bacterial counts of serial stool specimens were examined for the first eight weeks after birth in 10 infants. The colonisation rates of administered bacteria were examined using immunohistochemical staining of stool specimens with a B breve specific monoclonal antibody. RESULTS—In the preliminary study there were no side effects attributable to the bacteria. Immunohistochemical staining of stool specimens showed that the colonisation rates of the administered bacteria were 73% at 2 weeks of age, but only 12% in the control group. Early administration of B breve significantly decreased aspirated air volume from the stomach and improved weight gain. CONCLUSIONS—B breve can colonise the immature bowel very effectively and is associated with fewer abnormal abdominal signs and better weight gain in VLBW infants, probably as a result of stabilisation of their intestinal flora and accelerated feeding schedules. Keywords: Bifidobacterium breve; stool specimens; necrotising enterocolitis; very low birthweight.

The aim of this study was to describe and compare neurodevelopmental outcomes with birthweight (BW) groups at 250-g intervals of very-low-birthweight (VLBW) infants at 3 years of age in a multicenter cohort in Japan.A total of 3104 VLBW infants born in 2003 and 2004 registered in a NICU-network database were followed in the study. Neurodevelopmental impairment (NDI) was defined as any of the following impairments: cerebral palsy, unilateral or bilateral blindness, severe hearing impairment, or developmental delay; a developmental quotient (DQ)70 measured using the Kyoto Scale of Psychological Development test or judged by physicians in infants without the test.A total of 257 infants died and follow-up data were obtained from 1826 infants. Of the 1826 infants, 155 (8.5%) had cerebral palsy, 25 (1.4%) had visual impairment, and 12 (0.7%) had hearing impairment. Of the 1197 infants in whom DQ was measured, 184 (15.4%) had DQ70. The proportion of NDI in the evaluated infants was 19.2% (n= 350), ranging from 11.9% (BW 1251-1500 g) to 42.0% (BW ≤ 500 g). Odds ratios (95%CI) of NDI or death against the group BW 1251-1500 g were 20.62 (13.29-31.97) in BW ≤ 500 g, 7.25 (5.45-9.64) in BW 501-750 g, 2.85 (2.12-3.82) in BW 751-1000 g and 1.18 (0.85-1.64) in BW 1001-1250 g.The increasing proportion of NDI or death, an indicator of adverse outcome, was associated with decrement in the BW of the groups. Although we have to consider a bias due to loss of follow-up data, the incidence of NDI was similar to previous overseas cohort studies despite the higher survival proportion in our study.

The aim of the present study was to explore the relationships among neonatal morbidity, interventions and death or adverse neurodevelopmental outcomes in very low-birthweight (VLBW) infants.Subjects were infants with birthweight ≤ 1500 g who were cared for in the tertiary neonatal intensive care units in Japan. Multiple logistic regression analysis was performed to examine the odds ratios (OR) and 95% confidence intervals (CI) of neonatal factors for death or cerebral palsy (CP) and death or developmental delay (developmental quotient70 or delay judged by physicians) at 3 years of age after adjusting for biological and prenatal variables.Of the 3104 subjects, 257 died and 1826 were evaluated at 3 years of age. Cystic periventricular leukomalacia (PVL; OR, 23.9; 95%CI: 11.0-51.7), gastrointestinal perforation (OR, 8.5; 95%CI: 2.8-25.4), intraventricular hemorrhage (IVH) grade 3 or 4 (OR, 3.1; 95%CI: 1.3-7.2) and sepsis (OR, 2.6; 95%CI: 1.4-4.8) were neonatal factors significantly associated with an increased risk of death or CP. Significant correlates with death or developmental delay were cystic PVL (OR, 7.9; 95%CI: 3.7-16.8), gastrointestinal perforation (OR, 6.3; 95%CI: 1.9-20.8), sepsis (OR, 2.8; 95%CI: 1.6-4.8), IVH grade 3 or 4 (OR, 2.6; 95%CI: 1.2-5.7), chronic lung disease at 36 weeks of corrected gestational age (OR, 1.6; 95%CI: 1.1-2.4) and treatment for retinopathy of prematurity (ROP; OR, 1.5; 95%CI: 1.0-2.3).Cystic PVL, gastrointestinal perforation, IVH and sepsis correlated with both death or CP and death or developmental delay in VLBW infants. Chronic lung disease at 36 weeks and treatment for ROP were associated with death or developmental delay, but not with death or CP.

A nationwide survey on neonatal surgery conducted by the Japanese Society of Pediatric Surgeons has demonstrated that the mortality of neonatal intestinal perforation has risen over the past 15 years. The incidence of intestinal perforation in extremely low-birthweight (ELBW) neonates has been increasing as more ELBW neonates survive and as the live-birth rate of ELBW has increased. In contrast to necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP), the pathogenesis of meconium-related ileus, defined as functional bowel obstruction characterized by delayed meconium excretion and microcolon, remains unclarified.The histology of 13 ELBW neonates with intestinal perforation secondary to meconium-related ileus was reviewed, and the radiology of 33 cases of meconium-related ileus diagnosed on contrast enema was reviewed. Specimens obtained from 16 ELBW neonates without gastrointestinal disease served as age-matched controls for histological assessment.The size of the ganglion cell nucleus in meconium-related ileus and in control subjects was 47.3 ± 22.0 µm(2) and 37.8 ± 11.6 µm(2), respectively, which was not significantly different. In all cases of meconium-related ileus, contrast enema demonstrated a microcolon or small-sized colon, with a gradual caliber change in the ileum and filling defects due to meconium in the ileum or colon, showing not-identical locations of caliber changes and filling defects.Morphological immaturity of ganglia was not suggested to be the pathogenesis of meconium-related ileus. Impaction of inspissated meconium is not the cause of obstruction, but the result of excessive water absorption in the hypoperistaltic bowel before birth, although the underlying mechanism responsible for the fetal hypoperistalsis remains unclear.

In this study, the relationship between the fluctuation in blood oxygen and carbon dioxide tension and the progression of acute retinopathy of prematurity (ROP) was evaluated. Eighteen extremely premature infants were selected on the basis of the following criteria: gestational age less than 26 weeks, oxygen supply or mechanical ventilation for more than 50 days, transcutaneous oxygen pressure (TcPO2) recorded almost once per hour, and arterial oxygen pressure (PaO2) and arterial carbon dioxide pressure (PaCO2) measured intermittently, for over 8 weeks after birth. All of these infants developed ROP, which ceased progressing in 7 infants (group I, stage 1 or 2 ROP, international classification), but advanced in 11 (group II, stage 3 or 3+). The fluctuations in TcPO2, PaO2, and PaCO2 are represented as coefficients of both variation (CV) and mean difference (D) in these two groups. The results demonstrate that both the CV and D values of TcPO2 are significantly elevated in group II infants compared with group I infants, in the first and second 3-weeks periods, and over the entire 9-week period after birth. The incidences of extreme hyperoxemia (TcPO2 > or = 100 mm Hg) and hypoxemia (TcPO2 < 30 mm Hg) in recorded TcPO2 time series show no significant differences between these two groups. We conclude that extremely premature infants with widely fluctuating arterial oxygen tension may have a greater chance of developing progressive ROP.

Interleukin-8 (IL-8) exerts chemotactic activity on neutrophils at inflammatory sites to eliminate invading bacteria. To investigate whether the preterm fetus with chorioamnionitis produces IL-8, the titers of IL-8 were examined in sera of babies with (n = 38) and without chorioamnionitis (n = 34) using an EIA kit specific for IL-8. The infected babies had a significantly higher IL-8 titer than those not infected at 22-36 gestational weeks. The IL-8 titer was increased even in the mild histologic stage of chorioamnionitis and became much higher in the more severe stage. The IL-8 elevation, however, was remarkably suppressed by infusion of a steroid into the mother to promote fetal lung maturation. This retrospective study demonstrated that titration of IL-8 in cord serum is a more useful marker for the early detection of chorioamnionitis, because of its higher sensitivity and specificity, than conventional markers such as C-reactive protein.

Background: Doxapram is contraindicated for newborn infants in Japan because of its serious side effects. However, because of encouraging results of recent studies regarding the efficacy and safety of therapy for apnea of prematurity (AOP) with lower doses of doxapram than those previously proposed, approximately 60% of Japanese neonatologists continue to use doxapram at small doses. Caution is warranted because the sample sizes of the former studies are inadequate to evaluate doxapram for both its beneficial and harmful effects. Therefore, we conducted the present study in order to investigate the efficacy and harmful events of low-dose doxapram therapy for idiopathic AOP in very low-birth weight (VLBW) infants in a larger population. Methods: One hundred and six VLBW infants with idiopathic AOP were treated with doxapram at a dose of 0.2–1.0 mg/kg per h in combination with methylxanthines and the frequency of apnea and secondary outcomes were compared with a group of control infants. Results: An approximate 80% reduction in the frequency of apnea was found with only minimal side effects following low-dose doxapram. Although there were no significant differences in secondary outcomes between the doxapram-treated and control groups, mortality in doxapram-treated infants was significantly lower than that in control infants. Conclusions: Patients with AOP unresponsive to treatment with methylxanthines may benefit from the addition of low-dose doxapram.

Objective To evaluate the effectiveness of antenatal corticosteroid (ACS) to improve neonatal outcomes for infants born at Study design We performed a retrospective analysis of 11 607 infants born at 22 to 33 weeks of gestation between 2003 and 2007 from the Neonatal Research Network of Japan. We evaluated the gestational age effects of ACS administered to mothers with threatened preterm birth on several factors related to neonatal morbidity and mortality. Results By logistic regression analysis, ACS exposure decreased respiratory distress syndrome and severe intraventricular hemorrhage in infants born between 24 and 29 weeks of gestation. Cox regression analysis revealed that ACS exposure was associated with a significant decrease in mortality of preterm infants born at 22 or 23 weeks of gestation (adjusted hazard ratio, 0.72; 95% CI, 0.53 to 0.97; P = .03). This effect was also observed at 24 to 25 and 26 to 27 weeks of gestation and in the overall study population. Conclusions ACS exposure improved survival of extremely preterm infants. ACS treatment should be considered for threatened preterm birth at 22 to 23 weeks of gestation.