Birth defects (BDs) are an important cause of infant mortality and disproportionately occur among low birth weight infants. We determined the prevalence of BDs in a cohort of very low birth weight (VLBW) infants cared for at the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) centers over a 10-year period and examined the relationship between anomalies, neonatal outcomes, and surgical care.
Infant and maternal data were collected prospectively for infants weighing 401 to 1500 g at NRN sites between January 1, 1998, and December 31, 2007. Poisson regression models were used to compare risk of outcomes for infants with versus without BDs while adjusting for gestational age and other characteristics.
A BD was present in 1776 (4.8%) of the 37 262 infants in our VLBW cohort. Yearly prevalence of BDs increased from 4.0% of infants born in 1998 to 5.6% in 2007, P < .001. Mean gestational age overall was 28 weeks, and mean birth weight was 1007 g. Infants with BDs were more mature but more likely to be small for gestational age compared with infants without BDs. Chromosomal and cardiovascular anomalies were most frequent with each occurring in 20% of affected infants. Mortality was higher among infants with BDs (49% vs 18%; adjusted relative risk: 3.66 [95% confidence interval: 3.41–3.92]; P < .001) and varied by diagnosis. Among those surviving >3 days, more infants with BDs underwent major surgery (48% vs 13%, P < .001).
Prevalence of BDs increased during the 10 years studied. BDs remain an important cause of neonatal morbidity and mortality among VLBW infants.
birth defects; prematurity; Neonatal Research Network; low birth weight
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
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 feasibility of a randomized placebo controlled trial (RCT) of blood pressure (BP) management for extremely preterm infants.
This was a prospective pilot RCT of infants 230/7 – 266/7 weeks gestation who had protocol-defined low BP in the first 24 postnatal hours. Enrolled infants were administered a study infusion (dopamine or placebo) and a study syringe medication (hydrocortisone or placebo).
Of the 366 infants screened, 119 (33%) had low BP, 58 (16%) met all entry criteria, and 10 (3%) were enrolled. 161 (44%) infants were ineligible because they received early indomethacin. Only 17% of eligible infants were enrolled. Problems with consent included insufficient time, parent unavailability, and physician unwillingness to enroll critically ill infants. Two infants were withdrawn from the study due to the potential risk of intestinal perforation with simultaneous administration of hydrocortisone and indomethacin.
This pilot RCT was not feasible due to low eligibility and consent rates. An RCT of BP management for extremely preterm infants may require a waiver of consent for research in emergency care. The frequent use of early indomethacin and the associated risk of intestinal perforation when used with hydrocortisone may limit future investigations to only inotropic medications.
Extremely preterm infant; hypotension; hydrocortisone; dopamine; informed consent
Methods are required to predict prognosis with changes in clinical course. Death or neurodevelopmental impairment in extremely premature neonates can be predicted at birth/admission to the ICU by considering gender, antenatal steroids, multiple birth, birth weight, and gestational age. Predictions may be improved by using additional information available later during the clinical course. Our objective was to develop serial predictions of outcome by using prognostic factors available over the course of NICU hospitalization.
Data on infants with birth weight ≤1.0 kg admitted to 18 large academic tertiary NICUs during 1998–2005 were used to develop multivariable regression models following stepwise variable selection. Models were developed by using all survivors at specific times during hospitalization (in delivery room [n = 8713], 7-day [n = 6996], 28-day [n = 6241], and 36-week postmenstrual age [n = 5118]) to predict death or death/neurodevelopmental impairment at 18 to 22 months.
Prediction of death or neurodevelopmental impairment in extremely premature infants is improved by using information available later during the clinical course. The importance of birth weight declines, whereas the importance of respiratory illness severity increases with advancing postnatal age. The c-statistic in validation models ranged from 0.74 to 0.80 with misclassification rates ranging from 0.28 to 0.30.
Dynamic models of the changing probability of individual outcome can improve outcome predictions in preterm infants. Various current and future scenarios can be modeled by input of different clinical possibilities to develop individual “outcome trajectories” and evaluate impact of possible morbidities on outcome.
logistic models; premature infant; predictive value of tests; prognosis
Very low birth weight (VLBW) preterm infants are at risk for impaired cerebral autoregulation with pressure passive blood flow. Fluctuations in cerebral perfusion may occur in infants with a hemodynamically significant patent ductus arteriosus (hsPDA), especially during ductal closure. Our goal was to compare cerebral autoregulation using near-infrared spectroscopy (NIRS) in VLBW infants treated for a hsPDA.
This prospective observational study enrolled 28 VLBW infants with a hsPDA diagnosed by echocardiogram and 12 control VLBW infants without a hsPDA. NIRS cerebral monitoring was applied during conservative treatment, indomethacin, or surgical ligation. A cerebral pressure passivity index (PPI) was calculated and PPI differences were compared using a mixed effects regression model. Cranial ultrasound and MRI data were also assessed.
Infants with surgically ligated PDAs were more likely to have had a greater PPI within two hours following ligation compared with those treated with conservative management (p=0.04) or indomethacin (p=0.0007). These differences resolved six hours following treatment.
Cerebral autoregulation was better preserved after indomethacin treatment of a hsPDA compared with surgical ligation. Infants requiring surgical hsPDA ligation may be at increased risk for cerebral pressure passivity in the six hours following surgery.
near-infrared spectroscopy; neonate; pressure passivity; cerebral oxygenation
Aggressive phototherapy (AgPT) is widely used and assumed to be safe and effective for even the most immature infants. We assessed whether the benefits and hazards for the smallest and sickest infants differed from those for other extremely low birth weight (ELBW; (≤1000 g) infants in our Neonatal Research Network trial, the only large trial of AgPT.
ELBW infants (n=1974) were randomized to AgPT or conservative phototherapy at age 12–36 hours. The effect of AgPT on outcomes (death; impairment; profound impairment; death or impairment [primary outcome], and death or profound impairment) at 18–22 months corrected age was related to BW stratum (501–750 g; 751–1000 g) and baseline severity of illness using multilevel regression equations. The probability of benefit and of harm was directly assessed with Bayesian analyses.
Baseline illness severity was well characterized using mechanical ventilation and FiO2 at 24 hours age. Among mechanically ventilated infants ≤750 g BW (n =684), a reduction in impairment and in profound impairment was offset by higher mortality (p for interaction <0.05) with no significant effect on composite outcomes. Conservative Bayesian analyses of this subgroup identified a 99% (posterior) probability that AgPT increased mortality, a 97% probability that AgPT reduced impairment, and a 99% probability that AgPT reduced profound impairment.
Findings from the only large trial of AgPT suggest that AgPT may increase mortality while reducing impairment and profound impairment among the smallest and sickest infants. New approaches to reduce their serum bilirubin need development and rigorous testing.
Phototherapy; bilirubin; severity of illness; ELBW infant; impairment; randomized clinical trial; statistical interaction; Bayesian analysis
To compare risk-adjusted outcomes at 18–22 months corrected age for extremely low birth weight (ELBW) infants who never received phototherapy (NoPTx) to those who received any phototherapy (PTx) in the NICHD Neonatal Research Network randomized trial of Aggressive vs. Conservative Phototherapy.
Outcomes at 18–22 months corrected age included death, neurodevelopmental impairment (NDI), and Bayley Scales Mental Developmental Index (MDI). Regression models evaluated the independent association of PTx with adverse outcomes controlling for center and other potentially confounding variables.
Of 1972 infants, 216 were NoPTx and 1756 were PTx. For the entire 501–1000 g BW cohort, PTx was not independently associated with death or NDI (OR 0.85, 95% CI 0.60 –1.20), death, or adverse neurodevelopmental endpoints. However, among infants 501–750 g BW, the rate of significant developmental impairment with MDI<50 was significantly higher for NoPTx (29%) than PTx (12%) (p=0.004).
Phototherapy did not appear to be independently associated with death or NDI for the overall ELBW group. Whether PTx increases mortality could not be excluded due to bias from deaths before reaching conservative treatment threshold. The higher rate of MDI<50 in the 501–750g BW NoPTx group is concerning, and consistent with NRN Trial results.
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
This study was a two-center, stratified, parallel-group randomized trial comparing the effects of aggressive vs. conservative phototherapy on brainstem auditory evoked response (BAER) latencies in infants with extremely low birth weight (ELBW, ≤ 1,000 g).
BAER latencies of 751–1,000 g birth-weight infants were shorter by 0.37 ms (95% confidence interval (CI) = 0.02, 0.73) for wave V, 0.39 ms (0.08, 0.70) for wave III, and 0.33 ms (0.01, 0.65) for wave I after aggressive phototherapy at one center. Interwave intervals did not differ significantly. Similar nonsignificant trends were recorded for 501–750 g birth-weight infants. At the other participating center, no significant differences were recorded, cautioning against overgeneralizing these results.
The effects of bilirubin on the auditory pathway in ELBW infants depend on a complex interaction of bilirubin exposure, newborn characteristics, and clinical management.
Aggressive phototherapy was initiated sooner and continued at lower bilirubin levels than conservative phototherapy. A total of 174 ELBW infants were enrolled in the study; 111 infants were successfully tested at 35 weeks postmenstrual age (PMA); 57 died; and 6 were not successfully tested.
To examine risk factors for neonatal clinical seizures and to determine the independent association with death or neurodevelopmental impairment (NDI) in extremely low birth weight (ELBW) infants.
A total of 6499 ELBW infants (401–1000 g) surviving to 36 weeks postmenstrual age (PMA) were included in this retrospective study. Unadjusted comparisons were performed between infants with (n=414) and without (n=6085) clinical seizures during the initial hospitalization. Multivariate logistic regression modeling examined the independent association of seizures with late death (after 36 weeks PMA) or NDI after controlling for multiple demographic, perinatal, and neonatal variables.
Infants with clinical seizures had a greater proportion of neonatal morbidities associated with poor outcome, including severe intraventricular hemorrhage, sepsis, meningitis, and cystic periventricular leukomalacia (all P < .01). Survivors were more likely to have NDI or moderate-severe cerebral palsy at 18 to 22 months corrected age (both P < .01). After adjusting for multiple confounders, clinical seizures remained significantly associated with late death or NDI (odds ratio 3.15 [95% confidence interval 2.37–4.19]).
ELBW infants with clinical seizures are at increased risk for adverse neurodevelopmental outcome, independent of multiple confounding factors.
preterm; neurodevelopmental impairment; electroencephalography
The heptavalent pneumococcal-CRM197 conjugate vaccine (PCV-7) has been incompletely studied in very-low-birth-weight (VLBW, ≤1500 grams) infants.
To assess PCV-7 immunogenicity in VLBW, premature infants. We hypothesized that the frequency of post-vaccine antibody concentrations ≥0.15 µg/mL would vary directly with birth weight.
This was a multi-center observational study. Infants 401–1500 grams birth weight and <32 0/7 weeks gestation, stratified by birth weight, were enrolled from 9 NICHD Neonatal Research Network centers. Infants received PCV-7 at 2, 4 and 6 months after birth and had blood drawn 4–6 weeks following the third dose. Antibodies against the 7 vaccine serotypes were measured by enzyme-linked immunosorbent assay.
Of 369 enrolled infants, 244 completed their primary vaccine series by 8 months and had serum obtained. Subjects were 27.8 ± 2.2 (mean ± standard deviation) weeks gestation and 1008 ± 282 grams birth weight. Twenty-six percent had bronchopulmonary dysplasia and 16% had received postnatal glucocorticoids. Infants 1001–1500 grams birth weight were more likely than those 401–1000 grams to achieve antibody concentrations ≥0.15 µg/mL against the least two immunogenic serotypes (6B: 96% v. 85%, P = 0.003 and 23F: 97% v. 88%, P = 0.009). In multiple logistic regression analysis, lower birth weight, postnatal glucocorticoid use, lower weight at blood draw and Caucasian race were each independently associated with antibody concentrations <0.35 µg/mL against serotypes 6B and/or 23F.
When compared with larger premature infants, infants weighing ≤1000 grams at birth have similar antibody responses to most, but not all, PCV-7 vaccine serotypes.
Infant, premature; infant, very low birth weight; pneumococcal vaccines; immunization; vaccines
Current literature suggests that use of synchronized nasal intermittent positive pressure ventilation (SNIPPV), following extubation, reduces the rate of reintubation compared to nasal continuous positive airway pressure (NCPAP). However, there is limited information available on the outcomes of infants managed with SNIPPV.
To compare the outcomes of infants managed with SNIPPV (postextubation or for apnea) to infants not treated with SNIPPV at 2 sites.
Clinical retrospective data was used to evaluate the use of SNIPPV in infants ≤1250 g birth weight (BW); and 3 BW subgroups (500 –750, 751–1000, and 1001–1250 g, decided a priori). SNIPPV was not assigned randomly. Bronchopulmonary dysplasia (BPD) was defined as treatment with supplemental oxygen at 36 weeks’ postmenstrual age.
Overall, infants who were treated with SNIPPV had significantly lower mean BW (863g vs. 964g) and gestational age (26.4 weeks vs. 27.9 weeks), more frequently received surfactant (85% vs. 68%), and had a higher incidence of BPD or death (39% vs. 27%) (all p<0.01), compared to infants treated with NCPAP. In the subgroup analysis, SNIPPV was associated with lower rates of BPD (43% vs 67%, P = .03) and BPD/death (51% vs 76%, P = .02) in the 500- to 750g infants, with no significant differences in the other BW groups. Logistic regression analysis, adjusting for significant covariates, revealed infants with 500 –700-g BW who received SNIPPV were significantly less likely to have the outcomes of BPD (OR: 0.29 [95% CI: 0.11– 0.77]; P = .01), BPD/death (OR: 0.30 [95% CI: 0.11– 0.79]; P = .01), neurodevelopmental impairment (NDI) (OR: 0.29 [95% CI: 0.09–0.94]; P = .04), and NDI/death (OR: 0.18 [95% CI: 0.05– 0.62]; P = .006).
SNIPPV use in infants at greatest risk of BPD or death (500-750g) was associated with decreased BPD, BPD/death, NDI, and NDI/death when compared to infants managed with NCPAP.
premature newborn; respiratory distress syndrome; non-invasive ventilation
It is unclear whether aggressive phototherapy to prevent neurotoxic effects of bilirubin benefits or harms infants with extremely low birth weight (1000 g or less).
We randomly assigned 1974 infants with extremely low birth weight at 12 to 36 hours of age to undergo either aggressive or conservative phototherapy. The primary outcome was a composite of death or neurodevelopmental impairment determined for 91% of the infants by investigators who were unaware of the treatment assignments.
Aggressive phototherapy, as compared with conservative phototherapy, significantly reduced the mean peak serum bilirubin level (7.0 vs. 9.8 mg per deciliter [120 vs. 168 μmol per liter], P<0.01) but not the rate of the primary outcome (52% vs. 55%; relative risk, 0.94; 95% confidence interval [CI], 0.87 to 1.02; P = 0.15). Aggressive phototherapy did reduce rates of neurodevelopmental impairment (26%, vs. 30% for conservative phototherapy; relative risk, 0.86; 95% CI, 0.74 to 0.99). Rates of death in the aggressive-phototherapy and conservative-phototherapy groups were 24% and 23%, respectively (relative risk, 1.05; 95% CI, 0.90 to 1.22). In preplanned subgroup analyses, the rates of death were 13% with aggressive phototherapy and 14% with conservative phototherapy for infants with a birth weight of 751 to 1000 g and 39% and 34%, respectively (relative risk, 1.13; 95% CI, 0.96 to 1.34), for infants with a birth weight of 501 to 750 g.
Aggressive phototherapy did not significantly reduce the rate of death or neurodevelopmental impairment. The rate of neurodevelopmental impairment alone was significantly reduced with aggressive phototherapy. This reduction may be offset by an increase in mortality among infants weighing 501 to 750 g at birth. (ClinicalTrials. gov number, NCT00114543.)
To identify the variables that predict death/physiologic BPD in preterm infants with severe respiratory failure.
The study was a secondary analysis of data from the NICHD Neonatal Research Network trial of inhaled nitric oxide (iNO) in preterm infants. Stepwise logistic regression models and Classification and Regression Tree (CART) models were developed for the outcome of death or physiologic BPD (O2 at 36 weeks’ postmenstrual age).
Death and/or BPD was associated with lower birth weight, higher oxygen requirement, male gender, additional surfactant doses, higher oxygenation index, and outborn status, but not the magnitude of response in PaO2 to iNO. The positive predictive value of the CART model was 82% at 95% sensitivity.
The major factors associated with death/BPD were an increased severity of respiratory failure, lower birth weight, male gender, and outborn status, but not the magnitude of initial response to iNO.
Logistic models; Predictive value of tests; ROC curve
To assess interobserver reliability between two central readers of cranial ultrasound (CUS) and accuracy of local compared with central interpretations.
A retrospective analysis of CUS data from the NICHD trial of inhaled nitric oxide for premature infants. Interobserver reliability of two central readers was assessed by kappa or weighted kappa. Accuracy of local compared with central interpretations was assessed by sensitivity and specificity.
Cranial US from 326 infants had both central reader and local interpretations. Central reader agreement for grade 3/4 IVH, grade 3/4 IVH or PVL, grade of IVH, and degree of ventriculomegaly was very good (kappa=0.84, 0.81, 0.79, and 0.75, respectively). Agreement was poor for lower grade IVH and for PVL alone. Local interpretations were highly accurate for grade 3/4 IVH or PVL (sensitivity 87–90%, specificity 92–93%), but sensitivity was poor to fair for grade 1/2 IVH (48–68%) and PVL (20–44%).
Our findings demonstrate reliability and accuracy of highly unfavorable CUS findings, but suggest caution when interpreting mild to moderate IVH or white matter injury.
intraventricular; hemorrhage; leukomalacia; central reader; neurodevelopmental; brain
We sought to determine if inhaled nitric oxide (iNO) administered to preterm infants with premature rupture of membranes (PPROM), oligohydramnios, and pulmonary hypoplasia improved oxygenation, survival, or other clinical outcomes. Data were analyzed from infants with suspected pulmonary hypoplasia, oligohydramnios, and PPROM enrolled in the National Institute of Child Health and Development Neonatal Research Network Preemie Inhaled Nitric Oxide (PiNO) trial, where patients were randomized to receive placebo (oxygen) or iNO at 5 to 10 ppm. Outcome variables assessed were PaO2 response, mortality, bronchopulmonary dysplasia (BPD), and severe intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL). Twelve of 449 infants in the PiNO trial met criteria. Six infants received iNO and six received placebo. The iNO group had a mean increase in PaO2 of 39±50 mm Hg versus a mean decrease of 11±15 mm Hg in the control group. Mortality was 33% versus 67%, BPD (2/5) 40% versus (2/2) 100%, and severe IVH or PVL (1/5) 20% versus (1/2) 50% in the iNO and control groups, respectively. None of these changes were statistically significant. Review of a limited number of cases from a large multicenter trial suggests that iNO use in the setting of PPROM, oligohydramnios, and suspected pulmonary hypoplasia improves oxygenation and may decrease the rate of BPD and death without increasing severe IVH or PVL. However, the small sample size precludes definitive conclusions. Further studies are required to determine if iNO is of benefit in this specific patient population.
Nitric oxide; pulmonary hypoplasia; oligohydramnios; PPROM; bronchopulmonary dysplasia
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
The objective of our study was to examine the relationship between brain injury and outcome following neonatal hypoxic–ischaemic encephalopathy treated with hypothermia.
Design and patients
Neonatal MRI scans were evaluated in the National Institute of Child Health and Human Development (NICHD) randomised controlled trial of whole-body hypothermia and each infant was categorised based upon the pattern of brain injury on the MRI findings. Brain injury patterns were assessed as a marker of death or disability at 18–22 months of age.
Scans were obtained on 136 of 208 trial participants (65%); 73 in the hypothermia and 63 in the control group. Normal scans were noted in 38 of 73 infants (52%) in the hypothermia group and 22 of 63 infants (35%) in the control group. Infants in the hypothermia group had fewer areas of infarction (12%) compared to infants in the control group (22%). Fifty-one of the 136 infants died or had moderate or severe disability at 18 months. The brain injury pattern correlated with outcome of death or disability and with disability among survivors. Each point increase in the severity of the pattern of brain injury was independently associated with a twofold increase in the odds of death or disability.
Fewer areas of infarction and a trend towards more normal scans were noted in brain MRI following whole-body hypothermia. Presence of the NICHD pattern of brain injury is a marker of death or moderate or severe disability at 18–22 months following hypothermia for neonatal encephalopathy.
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
Inhaled nitric oxide (iNO) is an effective therapy for pulmonary hypertension and hypoxic respiratory failure in term infants. Fourteen randomized controlled trials (n = 3430 infants) have been conducted on preterm infants at risk for chronic lung disease (CLD). The study results seem contradictory.
Individual-patient data meta-analysis included randomized controlled trials of preterm infants (<37 weeks' gestation). Outcomes were adjusted for trial differences and correlation between siblings.
Data from 3298 infants in 12 trials (96%) were analyzed. There was no statistically significant effect of iNO on death or CLD (59% vs 61%: relative risk [RR]: 0.96 [95% confidence interval (CI): 0.92–1.01]; P = .11) or severe neurologic events on imaging (25% vs 23%: RR: 1.12 [95% CI: 0.98–1.28]; P = .09). There were no statistically significant differences in iNO effect according to any of the patient-level characteristics tested. In trials that used a starting iNO dose of >5 vs ≤5 ppm there was evidence of improved outcome (interaction P = .02); however, these differences were not observed at other levels of exposure to iNO. This result was driven primarily by 1 trial, which also differed according to overall dose, duration, timing, and indication for treatment; a significant reduction in death or CLD (RR: 0.85 [95% CI: 0.74–0.98]) was found.
Routine use of iNO for treatment of respiratory failure in preterm infants cannot be recommended. The use of a higher starting dose might be associated with improved outcome, but because there were differences in the designs of these trials, it requires further examination.
inhaled nitric oxide; chronic lung disease; respiratory disease; preterm infants; individual-patient data meta-analysis
Invasive candidiasis is a leading cause of infection-related morbidity and mortality in extremely low-birth-weight (<1000 g) infants. We quantify risk factors predicting infection in high-risk premature infants and compare clinical judgment with a prediction model of invasive candidiasis.
The study involved a prospective observational cohort of infants <1000 g birth weight at 19 centers of the NICHD Neonatal Research Network. At each sepsis evaluation, clinical information was recorded, cultures obtained, and clinicians prospectively recorded their estimate of the probability of invasive candidiasis. Two models were generated with invasive candidiasis as their outcome: 1) potentially modifiable risk factors and 2) a clinical model at time of blood culture to predict candidiasis.
Invasive candidiasis occurred in 137/1515 (9.0%) infants and was documented by positive culture from ≥ 1 of these sources: blood (n=96), cerebrospinal fluid (n=9), urine obtained by catheterization (n=52), or other sterile body fluid (n=10). Mortality was not different from infants who had positive blood culture compared to those with isolated positive urine culture. Incidence varied from 2–28% at the 13 centers enrolling ≥ 50 infants. Potentially modifiable risk factors (model 1) included central catheter, broad-spectrum antibiotics (e.g., third-generation cephalosporins), intravenous lipid emulsion, endotracheal tube, and antenatal antibiotics. The clinical prediction model (model 2) had an area under the receiver operating characteristic curve of 0.79, and was superior to clinician judgment (0.70) in predicting subsequent invasive candidiasis. Performance of clinical judgment did not vary significantly with level of training.
Prior antibiotics, presence of a central catheter, endotracheal tube, and center were strongly associated with invasive candidiasis. Modeling was more accurate in predicting invasive candidiasis than clinical judgment.
Candidiasis; premature infant; risk factors
This report presents data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network on care of and morbidity and mortality rates for very low birth weight infants, according to gestational age (GA).
Perinatal/neonatal data were collected for 9575 infants of extremely low GA (22–28 weeks) and very low birth weight (401–1500 g) who were born at network centers between January 1, 2003, and December 31, 2007.
Rates of survival to discharge increased with increasing GA (6% at 22 weeks and 92% at 28 weeks); 1060 infants died at ≤ 12 hours, with most early deaths occurring at 22 and 23 weeks (85% and 43%, respectively). Rates of prenatal steroid use (13% and 53%, respectively), cesarean section (7% and 24%, respectively), and delivery room intubation (19% and 68%, respectively) increased markedly between 22 and 23 weeks. Infants at the lowest GAs were at greatest risk for morbidities. Overall, 93% had respiratory distress syndrome, 46% patent ductus arteriosus, 16% severe intraventricular hemorrhage, 11% necrotizing enterocolitis, and 36% late-onset sepsis. The new severity-based definition of bronchopulmonary dysplasia classified more infants as having bronchopulmonary dysplasia than did the traditional definition of supplemental oxygen use at 36 weeks (68%, compared with 42%). More than one-half of infants with extremely low GAs had undetermined retinopathy status at the time of discharge. Center differences in management and outcomes were identified.
Although the majority of infants with GAs of ≥24 weeks survive, high rates of morbidity among survivors continue to be observed.
extremely low gestation; very low birth weight; morbidity; death
Postnatal steroid use in bronchopulmonary dysplasia (BPD) decreases lung inflammation but increases impairment (NDI). We hypothesized that increased dose is associated with increased NDI, lower postmenstrual age (PMA) at exposure increases NDI and risk of BPD modifies the effect of PNS.
Steroid dose and timing of exposure beyond 7 days was assessed among 2358 ELBW nested in a prospective trial, with 1667 (84%) survivors examined at 18-22 months PMA. Logistic regression tested the relationship between NDI (Bayley MDI/PDI < 70, disabling cerebral palsy (CP) or sensory impairment), total dose (tertiles < 0.9, 0.9-1.9, ≥ 1.9 mg/kg) and PMA at first dose. Separate logistic regression tested effect modification by BPD severity (Romagnoli Risk > 0.5 as high risk, n=2336 (99%) for days of life 4-7).
366 neonates (16%) were steroid treated (94% dexamethasone). Treated neonates were smaller and less mature. 72% of those treated were high risk for BPD. PNS exposure was associated with NDI/death (61 vs. 44%, p < 0.001). NDI increased with higher dose; 71% dead or impaired at highest dose tertile. Each 1 mg/kg was associated with a 2.0 point reduction in MDI and a 40% risk increase in disabling CP. (OR 1.4, 95% CI: 1.2-1.6). Older PMA did not mitigate the harm. Treatment after 33 weeks PMA was associated with greatest harm (NDI/death OR 2.5, 95% CI: 1.1-5.5) despite not receiving highest dose. The relationship of PNS to NDI was modified by BPD risk, (High risk OR 1.9, 95% CI: 1.4-2.6; Low risk OR 2.9, 95% CI: 1.8-4.8) with those at highest risk experiencing less harm.
Higher PNS dose was associated with increased NDI. There is no “safe” window for PNS use in ELBWs. Neonates with low BPD risk should not be exposed. A randomized trial of PNS for infants at highest risk is warranted.
postnatal corticosteroids; neurodevelopmental impairment; extremely low birth weight infants
Preterm infants requiring assisted ventilation are at significant risk of both pulmonary and cerebral injury. Inhaled Nitric Oxide, an effective therapy for pulmonary hypertension and hypoxic respiratory failure in the full term infant, has also been studied in preterm infants. The most recent Cochrane review of preterm infants includes 11 studies and 3,370 participants. The results show a statistically significant reduction in the combined outcome of death or chronic lung disease (CLD) in two studies with routine use of iNO in intubated preterm infants. However, uncertainty remains as a larger study (Kinsella 2006) showed no significant benefit for iNO for this combined outcome. Also, trials that included very ill infants do not demonstrate significant benefit. One trial of iNO treatment at a later postnatal age reported a decrease in the incidence of CLD. The aim of this individual patient meta-analysis is to confirm or refute these potentially conflicting results and to determine the extent to which patient or treatment characteristics may explain the results and/or may predict benefit from inhaled Nitric Oxide in preterm infants.
The Meta-Analysis of Preterm Patients on inhaled Nitric Oxide (MAPPiNO) Collaboration will perform an individual patient data meta-analysis to answer these important clinical questions. Studies will be included if preterm infants receiving assisted ventilation are randomized to receive inhaled Nitric Oxide or to a control group. The individual patient data provided by the Collaborators will be analyzed on an intention-to-treat basis where possible. Binary outcomes will be analyzed using log-binomial regression models and continuous outcomes will be analyzed using linear fixed effects models. Adjustments for trial differences will be made by including the trial variable in the model specification.
Thirteen (13) trials, with a total of 3567 infants are eligible for inclusion in the MAPPiNO systematic review. To date 11 trials (n = 3298, 92% of available patients) have agreed to participate. Funding was successfully granted from Ikaria Inc as an unrestricted grant. A collaborative group was formed in 2006 with data collection commencing in 2007. It is anticipated that data analysis will commence in late 2009 with results being publicly available in 2010.