Between-hospital variation in outcomes among extremely preterm infants is largely unexplained and may reflect differences in hospital practices regarding the initiation of active lifesaving treatment ...as compared with comfort care after birth.
We studied infants born between April 2006 and March 2011 at 24 hospitals included in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Data were collected for 4987 infants born before 27 weeks of gestation without congenital anomalies. Active treatment was defined as any potentially lifesaving intervention administered after birth. Survival and neurodevelopmental impairment at 18 to 22 months of corrected age were assessed in 4704 children (94.3%).
Overall rates of active treatment ranged from 22.1% (interquartile range IQR, 7.7 to 100) among infants born at 22 weeks of gestation to 99.8% (IQR, 100 to 100) among those born at 26 weeks of gestation. Overall rates of survival and survival without severe impairment ranged from 5.1% (IQR, 0 to 10.6) and 3.4% (IQR, 0 to 6.9), respectively, among children born at 22 weeks of gestation to 81.4% (IQR, 78.2 to 84.0) and 75.6% (IQR, 69.5 to 80.0), respectively, among those born at 26 weeks of gestation. Hospital rates of active treatment accounted for 78% and 75% of the between-hospital variation in survival and survival without severe impairment, respectively, among children born at 22 or 23 weeks of gestation, and accounted for 22% and 16%, respectively, among those born at 24 weeks of gestation, but the rates did not account for any of the variation in outcomes among those born at 25 or 26 weeks of gestation.
Differences in hospital practices regarding the initiation of active treatment in infants born at 22, 23, or 24 weeks of gestation explain some of the between-hospital variation in survival and survival without impairment among such patients. (Funded by the National Institutes of Health.).
Here we present an objective global climatology of polar lows. In order to obtain objective detection criteria, the efficacy of several parameters for separating polar lows from other cyclones has ...been compared. The comparison and the climatology are based on the ERA‐Interim reanalysis from 1979 to 2016 and the high‐resolution Arctic System Reanalysis from 2000 to 2012. The most effective parameters in separating polar lows from other extratropical cyclones were found to be the difference between the sea‐level pressure at the centre of the low and its surroundings, the difference in the potential temperature between the sea surface and the 500 hPa level, and the tropopause wind speed poleward of the system. Other parameters often used to identify polar lows, such as the 10 m wind speed and the temperature difference between the sea surface and the 700 hPa level, were found to be less effective. The climatologies reveal that polar lows occur in all marine basins at high latitudes, but with high occurrence density in the vicinity of the sea‐ice edge and coastal zones. The regions showing the highest degree of polar‐low activity are the Denmark Strait and the Nordic Seas, especially for the most intense polar lows. In the North Atlantic and Pacific, the main polar‐low season ranges from November to March. In the Southern Hemisphere, polar lows are mainly detected between 50 and 65°S from April to October, indicating that this hemisphere compared to its northern counterpart has a two months longer, but less intense, polar‐low season. No significant hemispheric long‐term trends are observed, although some regions, such as the Denmark Strait and the Nordic Seas, experience significant downward and upward trends in polar lows, respectively, over the last decades. For intense polar lows, a significant declining trend has been observed for the Northern Hemisphere.
Polar lows are intense mesoscale cyclones developing in the winter season over oceans at high latitudes. In this study, the efficacy of several parameters for polar detection are compared and the most effective criteria are applied for the derivation of an objective global climatology of polar lows. The average spatial distribution of polar‐low activity is presented in the figure, revealing the Nordic Seas and the Denmark Strait as most active regions.
Background.Infectious diseases (IDs) cause widespread morbidity and mortality. We describe the epidemiology of ID hospitalizations in the United States with use of a nationally representative ...database. Methods.First-listed ID hospitalizations in the United States were analyzed using the Nationwide Inpatient Sample for 1998–2006. Hospitalization rates were calculated overall for IDs and for specific ID groups. Results.An estimated 40,085,978 (standard error, 255,418) hospitalizations with a first-listed ID occurred during 1998–2006, for an age-adjusted hospitalization rate of 154.4 (95% confidence interval, 153.3–155.5) hospitalizations per 10,000 persons. The rate increased slightly over the study period (152.5 95% confidence interval, 149.6–155.4 in 1998 vs 162.2 95% confidence interval, 158.7–165.5 in 2006); an increase was seen for both sexes, for older patients, and for Hispanic patients. Among those aged 5–39 years, female patients had a significantly higher hospitalization rate than did male patients; male patients had higher rates among the youngest children and adults aged ⩾40 years. Approximately 4.5 million hospital days and $865 billion in hospital charges were associated with primary ID hospitalizations over the study period. Lower respiratory tract infections were the most commonly listed ID (34.4%), followed by kidney, urinary tract, and bladder infections; cellulitis; and abdominal and rectal infections. Conclusions.The ID hospitalization rate increased during 1998–2006, reflecting an increase in ID hospitalizations among adults aged ⩾30 years, particularly older adults. Differences in trends and patterns of ID hospitalizations were noted by sex, age group, and race. Lower respiratory tract infections accounted for the largest proportion of ID hospitalizations. Future efforts should focus on preventive measures and improving early interventions for IDs.
Sepsis in the first 3 days of life is a leading cause of morbidity and mortality among infants. Group B Streptococcus (GBS), historically the primary cause of early-onset sepsis (EOS), has declined ...through widespread use of intrapartum chemoprophylaxis. We estimated the national burden of invasive EOS cases and deaths in the era of GBS prevention.
Population-based surveillance for invasive EOS was conducted in 4 of the Centers for Disease Control and Prevention's Active Bacterial Core surveillance sites from 2005 to 2008. We calculated incidence using state and national live birth files. Estimates of the national number of cases and deaths were calculated, standardizing by race and gestational age.
Active Bacterial Core surveillance identified 658 cases of EOS; 72 (10.9%) were fatal. Overall incidence remained stable during the 3 years (2005: 0.77 cases/1000 live births; 2008: 0.76 cases/1000 live births). GBS (∼ 38%) was the most commonly reported pathogen followed by Escherichia coli (∼ 24%). Black preterm infants had the highest incidence (5.14 cases/1000 live births) and case fatality (24.4%). Nonblack term infants had the lowest incidence (0.40 cases/1000 live births) and case fatality (1.6%). The estimated national annual burden of EOS was approximately 3320 cases (95% confidence interval CI: 3060-3580), including 390 deaths (95% CI: 300-490). Among preterm infants, 1570 cases (95% CI: 1400-1770; 47.3% of the overall) and 360 deaths (95% CI: 280-460; 92.3% of the overall) occurred annually.
The burden of invasive EOS remains substantial in the era of GBS prevention and disproportionately affects preterm and black infants. Identification of strategies to prevent preterm births is needed to reduce the neonatal sepsis burden.
Guidelines for prevention of group B streptococcal (GBS) infection have successfully reduced early onset (EO) GBS disease. Study results suggest that Escherichia coli is an important EO pathogen.
To ...determine EO infection rates, pathogens, morbidity, and mortality in a national network of neonatal centers.
Infants with EO infection were identified by prospective surveillance at Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Network centers. Infection was defined by positive culture results for blood and cerebrospinal fluid obtained from infants aged ≤72 hours plus treatment with antibiotic therapy for ≥5 days. Mother and infant characteristics, treatments, and outcomes were studied. Numbers of cases and total live births (LBs) were used to calculate incidence.
Among 396 586 LBs (2006-2009), 389 infants developed EO infection (0.98 cases per 1000 LBs). Infection rates increased with decreasing birth weight. GBS (43%, 0.41 per 1000 LBs) and E coli (29%, 0.28 per 1000 LBs) were most frequently isolated. Most infants with GBS were term (73%); 81% with E coli were preterm. Mothers of 67% of infected term and 58% of infected preterm infants were screened for GBS, and results were positive for 25% of those mothers. Only 76% of mothers with GBS colonization received intrapartum chemoprophylaxis. Although 77% of infected infants required intensive care, 20% of term infants were treated in the normal newborn nursery. Sixteen percent of infected infants died, most commonly with E coli infection (33%).
In the era of intrapartum chemoprophylaxis to reduce GBS, rates of EO infection have declined but reflect a continued burden of disease. GBS remains the most frequent pathogen in term infants, and E coli the most significant pathogen in preterm infants. Missed opportunities for GBS prevention continue. Prevention of E coli sepsis, especially among preterm infants, remains a challenge.
Infections during pregnancy have the potential to adversely impact birth outcomes. We evaluated the association between receipt of inactivated influenza vaccine during pregnancy and prematurity and ...small for gestational age (SGA) births.
We conducted a cohort analysis of surveillance data from the Georgia (United States) Pregnancy Risk Assessment Monitoring System. Among 4,326 live births between 1 June 2004 and 30 September 2006, maternal influenza vaccine information was available for 4,168 (96.3%). The primary intervention evaluated in this study was receipt of influenza vaccine during any trimester of pregnancy. The main outcome measures were prematurity (gestational age at birth <37 wk) and SGA (birth weight <10th percentile for gestational age). Infants who were born during the putative influenza season (1 October-31 May) and whose mothers were vaccinated against influenza during pregnancy were less likely to be premature compared to infants of unvaccinated mothers born in the same period (adjusted odds ratio OR = 0.60; 95% CI, 0.38-0.94). The magnitude of association between maternal influenza vaccine receipt and reduced likelihood of prematurity increased during the period of at least local influenza activity (adjusted OR = 0.44; 95% CI, 0.26-0.73) and was greatest during the widespread influenza activity period (adjusted OR = 0.28; 95% CI, 0.11-0.74). Compared with newborns of unvaccinated women, newborns of vaccinated mothers had 69% lower odds of being SGA (adjusted OR = 0.31; 95% CI, 0.13-0.75) during the period of widespread influenza activity. The adjusted and unadjusted ORs were not significant for the pre-influenza activity period.
This study demonstrates an association between immunization with the inactivated influenza vaccine during pregnancy and reduced likelihood of prematurity during local, regional, and widespread influenza activity periods. However, no associations were found for the pre-influenza activity period. Moreover, during the period of widespread influenza activity there was an association between maternal receipt of influenza vaccine and reduced likelihood of SGA birth.
Objectives To describe and compare the incidence of late-onset sepsis (LOS) and demographic and clinical characteristics associated with LOS in very low birth weight (VLBW) infants from singleton and ...multiple births, and to examine the heritability of susceptibility to LOS among VLBW twins by comparing same-sex and unlike-sex twin pairs. Study design The study group comprised infants with birth weight 401-1500 g seen at clinical centers of the Eunice Kennedy Shriver National Institute of Child and Human Development Neonatal Research Network between 2002 and 2008. Only the first episode of LOS was included in our analysis. Stepwise logistic regression models were fitted separately for singleton and multiple pregnancies to examine the maternal and neonatal factors associated with LOS. LOS due solely to gram-negative bacteria in singleton and multiple pregnancies was also examined in separate models. The heritability of LOS was estimated by examining the concordance of LOS in twins from same-sex and unlike-sex pairs. Results LOS occurred in 25.0% (3797 of 15 178) of singleton and 22.6% (1196 of 5294) of multiple-birth VLBW infants. Coagulase-negative staphylococci were the most common infecting organisms, accounting for 53.2% of all LOS episodes in singletons and 49.2% in multiples. Escherichia coli and Klebsiella species were the most commonly isolated gram-negative organisms, and Candida albicans was the most commonly isolated fungus. Concordance of LOS did not differ significantly between same-sex and unlike-sex twin pairs. Conclusion LOS remains a common problem in VLBW infants. The incidence of LOS is similar for singleton and multiple-birth infants. The similar concordance of LOS in same-sex and unlike-sex twin pairs provides no evidence that susceptibility to LOS among VLBW infants is genetically determined.
Objective To document the mortality and morbidity of infants weighing 501-1500 g at birth according to gestational age, birthweight, and sex. Study design Prospective collection of perinatal events ...and neonatal course to 120 days of life, discharge, or death from January 1990 through December 2002 for infants born at 16 participating centers of the National Institute of Child Health & Human Development Neonatal Research Network. Results Compared with 1995-1996, for 1997-2002 the survival of infants with birthweight of 501-1500 g increased by 1 percentage point (from 84% to 85%). Survival without major neonatal morbidity remained static, at 70%; this includes bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), and necrotizing enterocolitis (NEC). Survival increased for multiple births (26%, up from 22%), antenatal corticosteroid use (79%, up from 71%), and maternal antibiotics (70%, up from 62%) ( P < .05). From 1997 to 2002, birthweight-specific survival was 55% for infants weighing 501-750 g, 88% for 751-1000 g, 94% for 1001-1250 g, and 96% for 1251–1500 g. More females survived. The incidence of NEC (7%), severe IVH (12%), and late-onset septicemia (22%) remained essentially unchanged, but BPD decreased slightly, from 23% to 22%. The use of postnatal corticosteroids declined from 20% in 1997-2000 to 12% in 2001-2002. Growth failure (weight <10th percentile) at 36 weeks’ postmenstrual age decreased from 97% in 1995-1996 to 91% in 1997-2002. Conclusion There have been no significant increases in survival without neonatal and long-term morbidity among VLBW infants between 1997 and 2002. We speculate that to improve survival without morbidity requires determining, disseminating, and applying best practices using therapies currently available, and also identifying new strategies and interventions.
Chorioamnionitis is strongly linked to preterm birth and neonatal infection. The association between histological and clinical chorioamnionitis and cognitive, behavioral, and neurodevelopmental ...outcomes among extremely preterm neonates is less clear. We evaluated the impact of chorioamnionitis on 18- to 22-month neurodevelopmental outcomes in a contemporary cohort of extremely preterm neonates.
To compare the neonatal and neurodevelopmental outcomes of 3 groups of extremely low-gestational-age infants with increasing exposure to perinatal inflammation: no chorioamnionitis, histological chorioamnionitis alone, or histological plus clinical chorioamnionitis.
Longitudinal observational study at 16 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Two thousand three hundred ninety extremely preterm infants born at less than 27 weeks' gestational age (GA) between January 1, 2006, and December 31, 2008, with placental histopathology and 18 to 22 months' corrected age follow-up data were eligible.
Chorioamnionitis.
Outcomes included cerebral palsy, gross motor functional limitation, behavioral scores (according to the Brief Infant-Toddler Social and Emotional Assessment), cognitive and language scores (according to the Bayley Scales of Infant and Toddler Development, Third Edition), and composite measures of death/neurodevelopmental impairment. Multivariable logistic and linear regression models were developed to assess the association between chorioamnionitis and outcomes while controlling for important variables known at birth.
Neonates exposed to chorioamnionitis had a lower GA and higher rates of early-onset sepsis and severe periventricular-intraventricular hemorrhage as compared with unexposed neonates. In multivariable models evaluating death and neurodevelopmental outcomes, inclusion of GA in the model diminished the association between chorioamnionitis and adverse outcomes. Still, histological plus clinical chorioamnionitis was associated with increased risk of cognitive impairment as compared with no chorioamnionitis (adjusted odds ratio OR, 2.38 95% CI, 1.32 to 4.28 without GA; adjusted OR, 2.00 95% CI, 1.10 to 3.64 with GA as a covariate). Histological chorioamnionitis alone was associated with lower odds of death/neurodevelopmental impairment as compared with histological plus clinical chorioamnionitis (adjusted OR, 0.68 95% CI, 0.52 to 0.89 without GA; adjusted OR, 0.66 95% CI, 0.49 to 0.89 with GA as a covariate). Risk of behavioral problems did not differ statistically between groups.
Antenatal exposure to chorioamnionitis is associated with altered odds of cognitive impairment and death/neurodevelopmental impairment in extremely preterm infants.
PDF
