To describe and compare 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 in susceptibility to LOS among VLBW twins by comparing same-sex with unlike-sex twin pairs.
We studied infants with birth weight 401–1500 grams cared for at clinical centers of the NICHD Neonatal Research Network 2002–2008. Only the first episode of LOS was examined. Stepwise logistic regression models were fitted separately for singleton and multiple pregnancies to examine the maternal and neonatal factors associated with LOS. LOS due to only gram-negative bacteria among singleton and multiple pregnancies was also examined in separate models. The heritability of LOS was estimated by examining concordance of LOS between twins from same-sex and unlike-sex pairs.
LOS occurred in 25.0% (3797/15,178) of singleton and 22.6% (1196/5294) of multiple 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. E. coli and Klebsiella species were the most commonly isolated gram-negative organisms, and Candida albicans was the most commonly isolated fungus. Concordance of LOS was not significantly different between same-sex and unlike-sex twin pairs.
LOS remains a common problem in VLBW infants. The incidence of LOS is similar for singleton and multiple infants. Similar concordance of LOS in same-sex and unlike-sex twin pairs provided no evidence that susceptibility to LOS among VLBW infants is genetically determined.
Heredity; preterm infants; twins
Retinopathy of prematurity (ROP) and infantile hemangiomas are vascular disorders that may share common mechanisms. This study examined a potential clinical association between these disorders in populations of preterm infants at two hospitals in the U.S. and Hungary. Clinically collected data from infants with gestational ages less than 32 weeks born between May 1, 2007 and December 31, 2010 seen in the University of Iowa Children’s Hospital or the Department of Obstetrics and Gynecology, University of Pécs, were abstracted from electronic medical records and entered into a study database. Demographic and clinical variables were examined as potential covariates to the disorders of interest. Data were initially analyzed by center and then combined through meta-analysis. Six hundred eighty-four subjects were studied, 236 from Pécs and 448 from Iowa. There were no significant demographic differences between populations. Univariate analysis on each study population yielded covariates to ROP in each population, including infantile hemangioma, which were entered into a logistic regression model. These models were combined through random effects meta-analysis and demonstrated a significant relationship between infantile hemangioma and ROP (odds ratio=1.84, 95% confidence interval 1.08–3.12).
Infantile hemangioma and ROP co-occur in premature infant populations. Further studies are needed to investigate the pathogenesis of both disorders.
Angiogenesis; Hemangioma; Preterm infants; Retinopathy of prematurity; Vascular endothelial growth factor; Vasculogenesis
To investigate the relationships among blood pressure (BP) values, antihypotensive therapies, and in-hospital outcomes to identify a BP threshold below which antihypotensive therapies may be beneficial.
Prospective observational study of infants 230/7 to 266/7 weeks’ gestational age. Hourly BP values and antihypotensive therapy use in the first 24 hours were recorded. Low BP was investigated by using 15 definitions. Outcomes were examined by using regression analysis controlling for gestational age, the number of low BP values, and illness severity.
Of 367 infants enrolled, 203 (55%) received at least 1 antihypotensive therapy. Treated infants were more likely to have low BP by any definition (P < .001), but for the 15 definitions of low BP investigated, therapy was not prescribed to 3% to 49% of infants with low BP and, paradoxically, was administered to 28% to 41% of infants without low BP. Treated infants were more likely than untreated infants to develop severe retinopathy of prematurity (15% vs 8%, P = .03) or severe intraventricular hemorrhage (22% vs 11%, P < .01) and less likely to survive (67% vs 78%, P = .02). However, with regression analysis, there were no significant differences between groups in survival or in-hospital morbidity rates.
Factors other than BP contributed to the decision to use antihypotensive therapies. Infant outcomes were not improved with antihypotensive therapy for any of the 15 definitions of low BP investigated.
extremely preterm infant; antihypotensive therapy; blood pressure; hypotension
Myo-inositol given to preterm infants with respiratory distress has reduced death, increased survival without bronchopulmonary dysplasia (BPD) and reduced severe retinopathy of prematurity (ROP) in 2 randomized trials. Pharmacokinetic (PK) studies in extremely preterm infants are needed prior to efficacy trials.
Infants of 23–29 weeks gestation were randomized to a single intravenous (IV) dose of inositol at 60 or 120 mg/kg or placebo. Over 96 h, serum levels (sparse sampling population PK) and urine inositol excretion were determined. Population PK models were fit using a nonlinear mixed effects approach. Safety outcomes were recorded.
A 1-compartment model that included factors for endogenous inositol production, allometric size based on weight, gestational age (GA) strata and creatinine clearance fit the data best. The central volume of distribution was 0.5115 l/kg, the clearance 0.0679 l/kg/h, endogenous production 2.67 mg/kg/h and the half life 5.22 h when modeled without the covariates. During the first 12 h renal inositol excretion quadrupled in the 120 mg/kg group, returning to near baseline after 48 h. There was no diuretic side-effect. No significant differences in adverse events occurred between the 3 groups (p > 0.05).
A single compartment model accounting for endogenous production satisfactorily described the PK of IV inositol.
To examine whether preterm very low birth weight (VLBW) infants have an increased risk of late-onset sepsis (LOS) following early-onset sepsis (EOS).
Retrospective analysis of VLBW infants (401-1500 g) born September 1998 through December 2009 who survived >72 hours and were cared for within the NICHD Neonatal Research Network. Sepsis was defined by growth of bacteria or fungi in a blood culture obtained ≤72 hr of birth (EOS) or >72 hr (LOS) and antimicrobial therapy for ≥5 days or death <5 d while receiving therapy. Regression models were used to assess risk of death or LOS by 120d and LOS by 120d among survivors to discharge or 120d, adjusting for gestational age and other covariates.
Of 34,396 infants studied 504 (1.5%) had EOS. After adjustment, risk of death or LOS by 120d did not differ overall for infants with EOS compared with those without EOS [RR:0.99 (0.89-1.09)] but was reduced in infants born at <25wk gestation [RR:0.87 (0.76-0.99), p=0.048]. Among survivors, no difference in LOS risk was found overall for infants with versus without EOS [RR:0.88 (0.75-1.02)], but LOS risk was shorter in infants with BW 401-750 g who had EOS [RR:0.80 (0.64-0.99), p=0.047].
Risk of LOS after EOS was not increased in VLBW infants. Surprisingly, risk of LOS following EOS appeared to be reduced in the smallest, most premature infants, underscoring the need for age-specific analyses of immune function.
Very low birth weight; early-onset sepsis; late-onset sepsis
To assess the use of nasal high-frequency ventilation (HFV) to provide noninvasive ventilatory support for very low birthweight (VLBW) infants.
VLBW infants, >7 days of age on nasal continuous positive airway pressure (CPAP), were placed on nasal HFV for 2 h using the Infant Star high-frequency ventilator (Mallinckrodt, Inc., St. Louis, MO, USA). Mean airway pressure was set to equal the previous level of CPAP, and amplitude was adjusted to obtain chest wall vibration. Capillary blood was sampled before starting HFV and after 2 h to determine change in pH and partial pressure of carbon dioxide (pCO2).
Fourteen subjects were studied, 10 males and 4 females. Gestational age was 26–30 weeks (median 27). Age at study was 18–147 days (median 30). Median birth weight was 955 g; median weight at study was 1605 g. Nasal CPAP pressure was 4–7 cm H2O (mean 5). Amplitude was 30–60 (median 50). After 2 h, PCO2 (mean 45 torr) was significantly lower than initial PCO2 (mean 50 torr) (p = 0.01), and pH had increased significantly (7.40 vs. 7.37, p = 0.04).
Nasal HFV is effective in decreasing pCO2 in stable premature infants requiring nasal CPAP support. Long-term use of nasal HFV requires further study.
CPAP; High-frequency ventilation; Nasal ventilation; Premature infant
The purpose of this study was to evaluate immediate auditory and visual memory processes in learning disability subtypes of 40 children born preterm. Three subgroups of children were examined: (a) primary language disability group (n = 13), (b) perceptual-motor disability group (n = 14), and (c) no learning disability diagnosis group without identified language or perceptual-motor learning disability (n = 13). Between-group comparisons indicate no significant differences in immediate auditory or visual memory performances between language and perceptual-motor learning disability groups. Within-group comparisons revealed that both learning disability groups performed significantly lower on a task of immediate memory when the mode of stimulus presentation and mode of response were visual.
Little is known about the outcomes of extremely low birth weight (ELBW) preterm infants with congenital heart defects (CHDs). The aim of this study was to assess the mortality, morbidity, and early childhood outcomes of ELBW infants with isolated CHD compared with infants with no congenital defects. Participants were 401–1,000 g infants cared for at National Institute of Child Health and Human Development Neonatal Research Network centers between January 1, 1998 and December 31, 2005. Neonatal morbidities and 18–22 months’ corrected age outcomes were assessed. Neurodevelopmental impairment (NDI) was defined as moderate to severe cerebral palsy, Bayley II mental or psychomotor developmental index < 70, bilateral blindness, or hearing impairment requiring aids. Poisson regression models were used to estimate relative risks for outcomes while adjusting for gestational age, small for gestational-age status, and other variables. Of 14,457 ELBW infants, 110 (0.8 %) had isolated CHD, and 13,887 (96 %) had no major birth defect. The most common CHD were septal defects, tetralogy of Fallot, pulmonary valve stenosis, and coarctation of the aorta. Infants with CHD experienced increased mortality (48 % compared with 35 % for infants with no birth defect) and poorer growth. Surprisingly, the adjusted risks of other short-term neonatal morbidities associated with prematurity were not significantly different. Fifty-seven (52 %) infants with CHD survived to 18–22 months’ corrected age, and 49 (86 %) infants completed follow-up. A higher proportion of surviving infants with CHD were impaired compared with those without birth defects (57 vs. 38 %, p = 0.004). Risk of death or NDI was greater for ELBW infants with CHD, although 20% of infants survived without NDI.
heart defects; congenital; follow-up studies
Spontaneous intestinal perforation (SIP) is associated with the use of postnatal glucocorticoids and indometacin in extremely low birth weight (ELBW) infants. We hypothesized: 1) an association of SIP with the use of antenatal steroids (ANS) and indometacin either as prophylaxis for IVH (P Indo) or for treatment of PDA (Indo/PDA) and 2) an increased risk of death or abnormal neurodevelopmental outcomes in infants with SIP at 18-22 months corrected age.
We retrospectively identified ELBW infants with SIP in the Neonatal Research Network’s generic database. Unadjusted analysis identified the differences in maternal, neonatal and clinical variables between infants with and without SIP. Logistic regression analysis identified the adjusted odds ratio for SIP with reference to ANS, P Indo and Indo/PDA. Neurodevelopmental outcomes were assessed among survivors at 18 to 22 months corrected age.
Indo/PDA was associated with an increased risk of SIP (adjusted OR 1.61; 95% CI 1.25,2.08), while P Indo and ANS were not. SIP was independently associated with an increased risk of death or NDI (adjusted OR−1.85; 95% CI 1.32,2.60) and NDI among survivors (adjusted OR−1.75, 95% CI 1.20,2.55).
Indometacin used for IVH prophylaxis and ANS were not associated with the occurrence of SIP in ELBW infants. Indometacin used for treatment of symptomatic PDA was however associated with an increased risk of SIP. ELBW infants with SIP have an increased risk of poor neurodevelopmental outcomes.
extremely low birth weight infant; intestinal perforation; indometacin; cerebral palsy
The safe lower limit of hematocrit or hemoglobin that should trigger a red blood cell (RBC) transfusion has not been defined. The objective of this study was to examine the physiological effects of anemia and compare the acute responses to transfusion in preterm infants who were transfused at higher or lower hematocrit thresholds.
We studied 41 preterm infants with birth weights 500-1300 g, who were enrolled in a clinical trial comparing high (“liberal”) and low (“restrictive”) hematocrit thresholds for transfusion. Measurements were performed before and after a packed RBC transfusion of 15 ml/kg, which was administered because the infant's hematocrit had fallen below the threshold defined by study protocol. Hemoglobin, hematocrit, red blood cell count, reticulocyte count, lactic acid, and erythropoietin were measured before and after transfusion using standard methods. Cardiac output was measured by echocardiography. Oxygen consumption was determined using indirect calorimetry. Systemic oxygen transport and fractional oxygen extraction were calculated.
Systemic oxygen transport rose in both groups following transfusion. Lactic acid was lower after transfusion in both groups. Oxygen consumption did not change significantly in either group. Cardiac output and fractional oxygen extraction fell after transfusion in the low hematocrit group only.
Our results demonstrate no acute physiological benefit of transfusion in the high hematocrit group. The fall in cardiac output with transfusion in the low hematocrit group shows that these infants had increased their cardiac output to maintain adequate tissue oxygen delivery in response to anemia and, therefore, may have benefitted from transfusion.
Neonatology; haematology; circulatory; physiology; clinical procedures
To assess the impact of emperic antifungal therapy of invasive candidiasis on subsequent outcomes in premature infants.
This was a cohort study of infants ≤1000 g birth weight cared for at Neonatal Research Network sites. All infants had at least 1 positive culture for Candida. Emperic antifungal therapy was defined as receipt of a systemic antifungal on the day of or the day before the first positive culture for Candida was drawn. We created Cox proportional hazards and logistic regression models stratified on propensity score quartiles to determine the effect of emperic antifungal therapy on survival, time to clearance of infection, retinopathy of prematurity, bronchopulmonary dysplasia, end-organ damage, and neurodevelopmental impairment (NDI).
136 infants developed invasive candidiasis. The incidence of death or NDI was lower for infants who received emperic antifungal therapy (19/38, 50%) compared with those who had not (55/86, 64%; odds ratio=0.27 [95% confidence interval 0.08–0.86]). There was no significant difference between the groups for any single outcome or other combined outcomes.
Emperic antifungal therapy was associated with increased survival without NDI. A prospective randomized trial of this strategy is warranted.
Candida; neonate; mortality; neurodevelopmental impairment
To explore the association of serum bilirubin level and breast milk feeding with retinopathy of prematurity (ROP) in preterm infants.
We conducted a case-control study to examine the independent and combined effects of serum bilirubin and breast milk feeding on ROP risk in infants <32 weeks gestation or with birth weight <1500 grams. Cases (66 infants with ROP) were matched with controls (66 infants without ROP) based on factors know to affect ROP risk.
When analyzed using the paired t test, the peak bilirubin levels were lower in ROP cases than in controls (mean 7.2 vs 7.9 mg/dl; P=0.045). Using conditional logistic regression, we found a negative association between highest serum bilirubin level and risk of ROP (OR=0.82 per 1-mg/dl change in bilirubin (P=0.06). There was no significant association between breast milk feeding and risk of ROP.
Bilirubin may help to protect preterm infants against ROP.
bilirubin; breast milk; preterm; retinopathy of prematurity
To evaluate maternal and neonatal risk factors associated with post-neonatal intensive care unit (NICU) discharge mortality among ELBW infants.
This is a retrospective analysis of extremely low birth weight (<1,000 g) and <27 weeks' gestational age infants born in the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neonatal Research Network sites from January 2000 to June 2007. Infants were tracked until death or 18–22 months corrected age. Infants who died between NICU discharge and the 18–22 month follow-up visit were classified as post-NICU discharge mortality. Association of maternal and infant risk factors with post-NICU discharge mortality was determined using logistic regression analysis. A prediction model with six significant predictors was developed and validated.
5,364 infants survived to NICU discharge. 557 (10%) infants were lost to follow-up, and 107 infants died following NICU discharge. Post-NICU discharge mortality rate was 22.3 per 1000 ELBW infants. In the prediction model, African-American race, unknown maternal health insurance, and hospital stay ≥120 days significantly increased risk, and maternal exposure to intra-partum antibiotics was associated with decreased risk of post-NICU discharge mortality.
We identified African-American race, unknown medical insurance and prolonged NICU stay as risk factors associated with post-NICU discharge mortality among ELBW infants.
extremely preterm infants; discharge; mortality; predictive model
We compared neurodevelopmental outcomes of extremely low birth weight (ELBW) infants with and without bronchopulmonary dysplasia (BPD), using the physiologic definition.
ELBW (birth weights <1000 grams) infants admitted to the Neonatal Research Network centers and hospitalized at 36 weeks postmenstrual age (n=1,189) were classified using the physiologic definition of BPD. Infants underwent Bayley III assessment at 18-22 months corrected age. Multivariable logistic regression was used to determine the association between physiologic BPD and cognitive impairment (score < 70).
BPD by the physiologic definition was diagnosed in 603 (52%) infants, 537 of whom were mechanically ventilated or on FiO2 > 30% and 66 who failed the room air challenge. Infants on room air (n=505) and those who passed the room air challenge (n=51) were classified as “no BPD” (n=556). At follow up, infants with BPD had significantly lower mean weight and head circumference. Moderate to severe cerebral palsy (7 vs. 2.1%) and spastic diplegia (7.8 vs. 4.1%) and quadriplegia (3.9 vs. 0.9%) phenotypes as well as cognitive (12.8 vs. 4.6%) and language scores < 70 (24.2 vs. 12.3%) were significantly more frequent in those with BPD compared to those without BPD. BPD was independently associated (adjusted OR 2.4; 95% CI 1.40-4.13) with cognitive impairment.
Rates of adverse neurodevelopmental outcomes in early childhood were significantly higher in those with BPD. BPD by the physiologic definition was independently associated with cognitive impairment using Bayley Scales III. These findings have implications for targeted post-discharge surveillance and early intervention.
Outcome; preterm; bronchopulmonary dysplasia; physiologic definition
Individuals with Down syndrome (DS) are at increased risk of several morbidities with lifelong health consequences. Little is known about mortality or morbidity risks in early infancy among very-low-birth-weight (VLBW) infants with DS. Our objective was to compare survival and neonatal morbidities between VLBW infants with DS and VLBW infants with other non-DS chromosomal anomalies, other non-chromosomal birth defects, and VLBW infants without major birth defects.
Data were collected prospectively for infants weighing 401-1500 grams born and/or cared for at one of the study centers participating in the NICHD Neonatal Research Network from 1994 through 2008. Risk of death and morbidities including patent ductus arteriosus (PDA), necrotizing enterocolitis (NEC), late onset sepsis (LOS), retinopathy of prematurity (ROP), and bronchopulmonary dysplasia (BPD), were compared between VLBW infants with DS and infants in the other groups.
Infants with DS were at increased risk of death (adjusted relative risk [RR] 2.47, 95% confidence interval [CI] 2.00-3.07), PDA, NEC, LOS, and BPD relative to infants with no birth defects. Decreased risk of death (RR 0.40, 95% CI 0.31-0.52) and increased risks of NEC and LOS were observed when comparing infants with DS to infants with other non-DS chromosomal anomalies. Relative to infants with non-chromosomal birth defects, infants with DS were at increased risk of PDA and NEC.
The increased risk of morbidities among VLBW infants with DS provides useful information for counseling parents and for caretakers in anticipating the need for enhanced surveillance for prevention of these morbidities.
neonatal mortality; neonatal morbidity; preterm infants; Down syndrome; trisomy 21
We sought to determine if a center’s approach to care of premature infants at the youngest gestational ages (22–24 weeks’ gestation) is associated with clinical outcomes among infants of older gestational ages (25–27 weeks’ gestation).
Inborn infants of 401 to 1000 g birth weight and 22 0/7 to 27 6/7 weeks’ gestation at birth from 2002 to 2008 were enrolled into a prospectively collected database at 20 centers participating in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Markers of an aggressive approach to care for 22- to 24-week infants included use of antenatal corticosteroids, cesarean delivery, and resuscitation. The primary outcome was death before postnatal day 120 for infants of 25 to 27 weeks’ gestation. Secondary outcomes were the combined outcomes of death or a number of morbidities associated with prematurity.
Our study included 3631 infants 22 to 24 weeks’ gestation and 5227 infants 25 to 27 weeks’ gestation. Among the 22- to 24-week infants, use of antenatal corticosteroids ranged from 28% to 100%, cesarean delivery from 13% to 65%, and resuscitation from 30% to 100% by center. Centers with higher rates of antenatal corticosteroid use in 22- to 24-week infants had reduced rates of death, death or retinopathy of prematurity, death or late-onset sepsis, death or necrotizing enterocolitis, and death or neurodevelopmental impairment in 25- to 27-week infants.
This study suggests that physicians’ willingness to provide care to extremely low gestation infants as measured by frequency of use of antenatal corticosteroids is associated with improved outcomes for more-mature infants.
low-birth weight infant; NICUs; treatment; patient outcome assessment
To examine the impact of birth at night, on the weekend, and during July or August – the first months of the academic year – and the impact of resident duty-hour restrictions on mortality and morbidity of VLBW infants.
Outcomes were analyzed for 11,137 infants with birth weight 501–1250 grams enrolled in the NICHD Neonatal Research Network registry 2001–2005. Approximately half were born before the introduction of resident duty-hour restrictions in 2003. Follow-up assessment at 18–22 months was completed for 4,508 infants. Mortality (7-day and 28-day), short-term morbidities, and neurodevelopmental outcome were examined with respect to the timing of birth: night vs day, weekend vs weekday, and July or August vs other months, and after vs before implementation of resident duty-hour restrictions.
There was no effect of hour, day, or month of birth on mortality and no impact on the risks of short-term morbidities except the risk of ROP requiring operative treatment was lower for infants born during the late night hours than during the day. There was no impact of timing of birth on neurodevelopmental outcome except the risk of hearing impairment or death was slightly lower among infants born in July or August compared with other months. The introduction of resident and fellow duty-hour restrictions had no impact on mortality or neurodevelopmental outcome. The only change in short-term morbidity after duty-hour restrictions were introduced was an increase in the risk of ROP (stage 2 or higher).
In this network of academic centers, the timing of birth and the introduction of duty-hour restrictions had little effect on the risks of mortality and morbidity of VLBW infants, suggesting that staffing patterns were adequate to provide consistent care.
Neonatal; preterm infants; morbidity/mortality; resident education/training; workforce
To assess the long-term outcome of brain structure in preterm infants, at an average age of 12 years, who received a red blood cell transfusion for anemia of prematurity.
As neonates, this cohort of infants participated in a clinical trial in which they received red blood cell transfusions based on a high pretransfusion hematocrit threshold (liberal group) or a low hematocrit threshold (restricted group). These 2 preterm groups were compared with a group of full-term healthy control children.
Tertiary care hospital.
Magnetic resonance imaging scans for 44 of the original 100 subjects were obtained.
Liberal vs restricted transfusion.
Main Outcome Measures
Intracranial volume, total brain tissue, total cerebrospinal fluid, cerebral cortex and cerebral white matter volume, subcortical nuclei volume, and cerebellum volume.
Intracranial volume was substantially smaller in the liberal group compared with controls. Intracranial volume in the restricted group was not different from controls. Whole-cortex volume was not different in either preterm group compared with controls. Cerebral white matter was substantially reduced in both preterm groups, more so for the liberal group. The subcortical nuclei were substantially decreased in volume, equally so for both preterm groups compared with controls. When sex effects were evaluated, the girls in the liberal group had the most significant abnormalities.
Red blood cell transfusions affected the long-term outcome of premature infants as indicated by reduced brain volumes at 12 years of age for neonates who received transfusions using liberal guidelines.
Data are limited on the impact of methicillin-resistant Staphylococcus aureus (MRSA) on morbidity and mortality among very low birth weight (VLBW) infants with S aureus (SA) bacteremia and/or meningitis (B/M).
Neonatal data for VLBW infants (birth weight 401–1500 g) born January 1, 2006, to December 31, 2008, who received care at centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network were collected prospectively. Early-onset (≤72 hours after birth) and late-onset (>72 hours) infections were defined by blood or cerebrospinal fluid cultures and antibiotic treatment of ≥5 days (or death <5 days with intent to treat). Outcomes were compared for infants with MRSA versus methicillin-susceptible S aureus (MSSA) B/M.
Of 8444 infants who survived >3 days, 316 (3.7%) had SA B/M. Eighty-eight had MRSA (1% of all infants, 28% of infants with SA); 228 had MSSA (2.7% of all infants, 72% of infants with SA). No infant had both MRSA and MSSA B/M. Ninety-nine percent of MRSA infections were late-onset. The percent of infants with MRSA varied by center (P < .001) with 9 of 20 centers reporting no cases. Need for mechanical ventilation, diagnosis of respiratory distress syndrome, necrotizing enterocolitis, and other morbidities did not differ between infants with MRSA and MSSA. Mortality was high with both MRSA (23 of 88, 26%) and MSSA (55 of 228, 24%).
Few VLBW infants had SA B/M. The 1% with MRSA had morbidity and mortality rates similar to infants with MSSA. Practices should provide equal focus on prevention and management of both MRSA and MSSA infections among VLBW infants.
Staphylococcus aureus; methicillin resistant; infant; newborn
Our objective was to survey neonatologists regarding international practice of red cell transfusion thresholds for premature infants with <1000-g birth weight and/or <28-week gestation. An invitation to fill out an 11-question web-based survey was distributed to neonatologists through their professional societies in 22 countries. Physicians were asked about which specific factors, in addition to hemoglobin levels, influenced their decisions about transfusing premature infants. These factors included gestational age, postnatal age, oxygen need, respiratory support, reticulocyte count, and inotropic support. Physicians were presented with 5 scenarios and asked to identify hemoglobin cutoff values for transfusing infants with <1000-g birth weight and/or <28-week gestation. One thousand eighteen neonatologists responded: the majority were from the United States (67.5%), followed by Germany (10.7%), Japan (8.0%), the United Kingdom (4.9%), Spain (3.9%), Italy (2.6%), Colombia (0.6%), Argentina (0.4%), Canada (0.4%), Belgium (0.1%), and the Netherlands (0.1%). Half of the respondents (51.1%) reported having a written policy with specific red cell transfusion guidelines in their unit. Factors considered “very important” regarding the need to administer blood transfusions included degree of oxygen requirement (44.7%) and need for respiratory support (44.1%). Erythropoietin was routinely used to treat anemia by 26.0% of respondents. Delayed cord clamping or cord milking was practiced by 29.1% of respondents. The main finding was of a wide variation in the hemoglobin values used to transfuse infants, regardless of postnatal age. Step-wise increments in the median hemoglobin cutoffs directly paralleled an increase in the need for levels of respiratory support. In the first week of life, there was a wider range in the distribution of hemoglobin transfusion thresholds for infants requiring no respiratory support and full mechanical ventilation compared with the thresholds used in the second, third, and fourth weeks of life. An international survey using hypothetical scenarios shows that red blood cell transfusion practices vary widely among practicing neonatologists in participating countries.
infant; extremely premature infant; extremely low birth weight; red blood cell transfusion; erythrocyte transfusion; international practices
Current guidelines, initially published in 1995, recommend antenatal corticosteroids for mothers with preterm labor from 24–34 weeks gestational age, but not before 24 weeks because of lack of data. However, many infants born before 24 weeks are provided intensive care now.
To determine if antenatal corticosteroids are associated with improvement in major outcomes in infants born at 22 and 23 weeks.
Design, Setting, Participants
Data for this cohort study were collected prospectively on 401–1000 gram inborn infants (N=10,541) of 22–25 weeks gestation born between 1993–2009 at 23 academic perinatal centers in the United States. Certified examiners unaware of exposure to antenatal corticosteroids performed follow-up examinations on 4,924 (86.5%) of the infants born in 1993–2008 who survived to 18–22 months. Logistic regression models generated adjusted odds ratios, controlling for maternal and neonatal variables.
Main Outcome Measures
Mortality and neurodevelopmental impairment at 18–22 months corrected age
Death or neurodevelopmental impairment at 18–22 months was lower for infants whose mothers received antenatal corticosteroids born at 23 weeks (antenatal corticosteroids, 83.4% vs no antenatal corticosteroids, 90.5%; adjusted odds ratio 0.58; 95% CI, 0.42–0.80), at 24 weeks (antenatal corticosteroids, 68.4% vs no antenatal corticosteroids, 80.3%; adjusted odds ratio 0.62; 95% CI, 0.49–0.78), and at 25 weeks (antenatal corticosteroids, 52.7% vs no antenatal corticosteroids, 67.9%; adjusted odds ratio 0.61; 95% CI, 0.50–0.74) but not at 22 weeks (antenatal corticosteroids, 90.2% vs no antenatal corticosteroids, 93.1%; adjusted odds ratio 0.80; 95% CI, 0.29–12.21). Death by 18–22 months, hospital death, death/intraventricular hemorrhage/periventricular leukomalacia, and death/necrotizing enterocolitis were significantly lower for infants born at 23, 24, and 25 weeks gestational age if the mothers had received antenatal corticosteroids but the only outcome significantly lower at 22 weeks was death/necrotizing enterocolitis (antenatal corticosteroids, 73.5% vs no antenatal corticosteroids, 84.5%; adjusted odds ratio 0.54; 95% CI, 0.30–0.97).
Among infants born at 23–25 weeks gestation, use of antenatal corticosteroids compared to non-use was associated with a lower rate of death or neurodevelopmental impairment at 18–22 months.
prematurity; infant mortality; neonatal intensive care; neurodevelopmental impairment; lung maturation; limits of viability
To examine pathogens and other characteristics associated with late-onset bloodstream infections (BSI) in infants with intestinal failure (IF) as a consequence of necrotizing enterocolitis (NEC).
Infants 401–1500 grams at birth who survived >72 hours and received care at NICHD Neonatal Research Network centers were studied. Frequency of culture positive BSI and pathogens were compared for infants with medical NEC, NEC managed surgically without IF, and surgical IF. Among infants with IF, duration of parenteral nutrition (PN) and other outcomes were evaluated.
932 infants were studied (IF, n=78; surgical NEC without IF, n=452; medical NEC, n=402). The proportion with BSI after NEC diagnosis was higher in infants with IF than with surgical NEC (p=0.007) or medical NEC (p<0.001). Gram positive pathogens were most frequent. Among infants with IF, increased number of infections was associated with longer hospitalization and duration on PN (0, 1, ≥2 infections; median stay (days): 172, 188, 260, p=0.06; median days on PN: 90, 112, 115, p=0.003), and the proportion who achieved full feeds during hospitalization decreased (87%, 67%, 50%, p=0.03).
Recurrent BSIs are common in VLBW infants with IF. Gram positive bacteria were most commonly identified in these infants.
Short bowel syndrome; Bloodstream infections; Late onset sepsis; Very low birth weight; Nutrition; Intestinal failure
Preterm infants are frequently transfused with red blood cells based on standardized guidelines or clinical concern that anemia taxes infants’ physiological compensatory mechanisms and thereby threatens their health and well-being. The impact of various transfusion guidelines on long-term neurocognitive outcome is not known. The purpose of this study is to evaluate long-term neurocognitive outcome on children born prematurely and treated at birth with different transfusion guidelines.
Neurocognitive outcomes were examined at school age for 56 preterm infants randomly assigned to a liberal (n = 33) or restrictive (n = 23) transfusion strategy. Tests of intelligence, achievement, language, visual-spatial/motor, and memory skills were administered. Between-group differences were assessed.
Those in the liberal transfusion group performed more poorly than those in the restrictive group on measures of associative verbal fluency, visual memory, and reading.
Findings highlight possible long-term neurodevelopmental consequences of maintaining higher hematocrit levels.
Preterm; Neuropsychology; Red Blood Cell Transfusion; Hematocrit; Longitudinal
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.
neonatal sepsis; group B streptococcal disease; Escherichia coli infection
Extremely low birth weight twins have a higher rate of death or neurodevelopmental impairment than singletons. Higher-order extremely low birth weight multiple births may have an even higher rate of death or neurodevelopmental impairment.
Extremely low birth weight (birth weight 401–1000 g) multiple births born in participating centers of the Neonatal Research Network between 1996 and 2005 were assessed for death or neurodevelopmental impairment at 18 to 22 months' corrected age. Neurodevelopmental impairment was defined by the presence of 1 or more of the following: moderate to severe cerebral palsy; mental developmental index score or psychomotor developmental index score less than 70; severe bilateral deafness; or blindness. Infants who died within 12 hours of birth were excluded. Maternal and infant demographic and clinical variables were compared among singleton, twin, and triplet or higher-order infants. Logistic regression analysis was performed to establish the association between singletons, twins, and triplet or higher-order multiples and death or neurodevelopmental impairment, controlling for confounding variables that may affect death or neurodevelopmental impairment.
Our cohort consisted of 8296 singleton, 2164 twin, and 521 triplet or higher-order infants. The risk of death or neurodevelopmental impairment was increased in triplets or higher-order multiples when compared with singletons (adjusted odds ratio: 1.7 [95% confidence interval: 1.29–2.24]), and there was a trend toward an increased risk when compared with twins (adjusted odds ratio: 1.27 [95% confidence: 0.95–1.71]).
Triplet or higher-order births are associated with an increased risk of death or neurodevelopmental impairment at 18 to 22 months' corrected age when compared with extremely low birth weight singleton infants, and there was a trend toward an increased risk when compared with twins.
extremely low birth weight; triplets; neurodevelopmental outcomes