To determine whether death and/or neurodevelopmental impairment (NDI) after severe intracranial hemorrhage (ICH; grade 3 or 4) differs by gestational age (GA) at birth in extremely low birth weight (ELBW) infants.
Demographic, perinatal and neonatal factors potentially contributing to NDI for ELBW infants (23 to 28 weeks gestation) were obtained retrospectively; outcome data came from the ELBW Follow-up Study. NDI was defined at 18 to 22 months corrected age as moderate/severe cerebral palsy, Bayley Scales of Infant Development II cognitive or motor score <70, and/or blindness or deafness. Characteristics of younger versus older infants with no versus severe ICH associated with death or NDI were compared. Generalized linear mixed models predicted death or NDI in each GA cohort.
Of the 6638 infants, 61.8% had no ICH and 13.6% had severe ICH; 39% of survivors had NDI. Risk-adjusted odds of death or NDI and death were higher in the lower GA group. Lower GA increased the odds of death before 30 days for infants with severe ICH. Necrotizing enterocolitis (particularly surgical NEC), late onset infection, cystic periventricular leukomalacia and post-natal steroids contributed to mortality risk. NDI differed by GA in infants without ICH and grade 3, but not grade 4 ICH. Contributors to NDI in infants with severe ICH included male gender, surgical NEC and post-hemorrhagic hydrocephalus requiring a shunt.
GA contributes to the risk of death in ELBW infants, but not NDI among survivors with severe ICH. Male gender, surgical NEC and need for a shunt add additional risk for NDI.
infant; premature; extremely low birth weight; death; neurodevelopmental impairment
To test the hypothesis that acidosis at birth is associated with the combined primary outcome of death or neurodevelopmental impairment (NDI) in extremely low birth weight (ELBW) infants, and to develop a predictive model of death/NDI exploring perinatal acidosis as a predictor variable.
The study population consisted of ELBW infants born between 2002-2007 at NICHD Neonatal Research Network hospitals. Infants with cord blood gas data and documentation of either mortality prior to discharge or 18-22 month neurodevelopmental outcomes were included. Multiple logistic regression analysis was used to determine the contribution of perinatal acidosis, defined as a cord blood gas with a pH<7 or base excess (BE)<-12, to death/NDI in ELBW infants. In addition, a multivariable model predicting death/NDI was developed.
3979 patients were identified of whom 249 had a cord gas pH<7 or BE<-12 mEq/L. 2124 patients (53%) had the primary outcome of death/NDI. After adjustment for confounding variables, pH<7 and BE<-12 mEq/L were each significantly associated with death/NDI (OR=2.5[1.6,4.2]; and OR=1.5[1.1,2.0], respectively). However, inclusion of pH or BE did not improve the ability of the multivariable model to predict death/NDI.
Perinatal acidosis is significantly associated with death/NDI in ELBW infants. Perinatal acidosis is infrequent in ELBW infants, however, and other factors are more important in predicting death/NDI.
Cord blood gas; Premature infant; Preterm infant; Neurodevelopmental impairment
To compare the risk-adjusted incidence of death or neuro-developmental impairment at 18–22 months corrected age, between twin and singleton extremely low birth weight infants.
Twin gestation is independently associated with increased risk of death or adverse neuro-developmental outcomes at 18–22 months corrected age in extremely low birth weight infants.
Retrospective study of inborn extremely low birth weight infants (BW 401– 1000g) admitted to NICHD Neonatal Research Network units between 1997 and 2005, who either died or had follow-up data available at 18–22 months corrected age. Neuro-developmental impairment (NDI), the primary outcome variable, was defined as the presence of any one of the following: moderate or severe cerebral palsy, severe bilateral hearing loss needing amplification, bilateral blindness, Bayley Mental Developmental Index or Psychomotor Developmental Index of less than 70. Death was included with NDI as a composite outcome since it is a competing variable. Results were compared for both twins, twin A, twin B, same sex twins, unlike sex twins and singleton infants. Logistic regression analysis was done to control for demographic and clinical factors that were different among the groups.
The cohort of infants who either died or were assessed for NDI consisted of 7,630 singleton infants and 1,376 twins. Logistic regression adjusting for clinical and socio-demographic risk factors showed an increased risk of death or NDI for twins as a group when compared with the singletons (OR-1.39, 95% CI- 1.19–1.63). On analyzing twin A and B separately as well, risk of death or NDI was increased in both twin A (OR-1.32, 95% CI- 1.09–1.59) and for twin B (OR-1.47, 95% CI- 1.21–1.78), when compared with singleton infants.
Twin gestation in ELBW infants is associated with an independent increased risk of death or NDI at 18–22 months corrected age, compared to ELBW singleton gestation infants. Both first and second born twins are at increased risk of death or NDI when compared to singleton ELBW infants.
twins; neuro-developmental impairment; extremely low birth weight infants
Extremely low birth weight (ELBW) infants with candiduria are at substantial risk for death or neurodevelopmental impairment. Therefore, identification of candiduria should prompt a systemic evaluation for disseminated Candida infection and initiation of treatment in all ELBW infants.
Background. Candidiasis carries a significant risk of death or neurodevelopmental impairment (NDI) in extremely low birth weight infants (ELBW; <1000 g). We sought to determine the impact of candiduria in ELBW preterm infants.
Methods. Our study was a secondary analysis of the Neonatal Research Network study Early Diagnosis of Nosocomial Candidiasis. Follow-up assessments included Bayley Scales of Infant Development examinations at 18–22 months of corrected age. Risk factors were compared between groups using exact tests and general linear modeling. Death, NDI, and death or NDI were compared using generalized linear mixed modeling.
Results. Of 1515 infants enrolled, 34 (2.2%) had candiduria only. Candida was isolated from blood only (69 of 1515 [4.6%]), cerebrospinal fluid (CSF) only (2 of 1515 [0.1%]), other sterile site only (not urine, blood, or CSF; 4 of 1515 [0.3%]), or multiple sources (28 of 1515 [2%]). Eleven infants had the same Candida species isolated in blood and urine within 3 days; 3 (27%) had a positive urine culture result first. Most urine isolates were Candida albicans (21 of 34 [62%]) or Candida parapsilosis (7 of 34 [29%]). Rate of death or NDI was greater among those with candiduria (50%) than among those with suspected but not proven infection (32%; odds ratio, 2.5 [95% confidence interval, 1.2–5.3]) after adjustment. No difference in death and death or NDI was noted between infants with candiduria and those with candidemia.
Conclusions. These findings provide compelling evidence that ELBW infants with candiduria are at substantial risk of death or NDI. Candiduria in ELBW preterm infants should prompt a systemic evaluation (blood, CSF, and abdominal ultrasound) for disseminated Candida infection and warrants treatment.
To determine the relative contribution of clinical data versus head ultrasound (HUS) in predicting neurodevelopmental impairment (NDI) in extremely low birth weight (ELBW) infants.
2103 ELBW infants (<1000g) admitted to a National Institute of Child Health and Human Development Neonatal Research Network center who had a HUS within the first 28 days, a repeat one around 36 weeks’ post-menstrual age, and neurodevelopmental assessment at 18–22 months corrected age were selected. Multivariate logistic regression models were developed using clinical and/or HUS variables. The primary outcome was the predictive abilities of the HUS done before 28 days after birth and closer to 36 weeks post-menstrual age, either alone or in combination with “Early” and “Late” clinical variables.
Models using clinical variables alone predicted NDI better than models with only HUS variables at both 28 days and 36 weeks (both p < 0.001), and addition of the HUS data did not improve prediction. NDI was absent in 30% and 28% of the infants with grade IV intracranial hemorrhage or periventricular leukomalacia, respectively, but was present in 39% of the infants with a normal head ultrasound.
Clinical models were better than head ultrasound models in predicting neurodevelopment.
Logistic models; Predictive value of tests; ROC curve; Infant; premature; Intracerebral hemorrhage; Leukomalacia; periventricular
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.
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
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
To compare the rates of adverse neurodevelopmental outcome or death at 18 to 22 months among extremely low birth weight (ELBW) infants born to mothers ≥ 40 years to the corresponding rates among infants of younger mothers.
Prospective evaluation of ELBW infants to quantify the relative risks of maternal age and multiple birth for death or adverse neurodevelopmental outcome.
The sample consisted of 14,671 live ELBW births divided into maternal age groups: <20; 20–29; 30–39; and ≥ 40 years. Of infants born to mothers ≥ 40 years, 20% were multiples. Mothers ≥ 40 years had high rates of obstetrical interventions and medical morbidities compared to mothers < 40 years. ELBW live births of mothers ≥ 40 years were 22 % more likely to survive and had a 13% decreased risk of neurodevelopmental impairment or death compared to mothers< 20. Multiple birth, however, was associated with a 10 % greater risk or neurodevelopmental impairment or death.
Although mothers ≥ 40 years had high pregnancy related morbidities, we found no overall increased risk of the composite outcome of death or NDI. Multiple birth, however, was a predictor of all adverse outcomes examined, regardless of maternal age.
outcomes; neurodevelopmental impairment; 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
Candida remains an important cause of late-onset infection in preterm infants. Mortality and neurodevelopmental outcome of extremely low birthweight (ELBW) infants enrolled in the Candida study was evaluated based on infection status.
ELBW infants born at NICHD Neonatal Research Network (NRN) centers between March 2004 and July 2007 screened for suspected sepsis were eligible for inclusion in the Candida study. Primary outcome data for neurodevelopmental impairment (NDI) or death were available for 1317/1515 (90%) of the infants enrolled in the Candida study. The Bayley Scales of Infant Development (BSID)-II or the BSID-III was administered at 18 months adjusted age. A secondary comparison with 864 infants registered with NRN enrolled during the same cohort never screened for sepsis and therefore not eligible for the Candida study was performed.
Among ELBW infants enrolled in the Candida study, 31% with Candida and 31% with late-onset non-Candida sepsis had NDI at 18 months. Infants with Candida sepsis and/or meningitis had an increased risk of death and were more likely to have the composite outcome of death and/or NDI compared with uninfected infants in adjusted analysis. Compared with infants in the NRN registry never screened for sepsis, overall risk for death were similar but those with Candida infection were more likely to have NDI (OR 1.83 (1.01,3.33, p=0.047).
In this cohort of ELBW infants, those with infection and/or meningitis were at increased risk for death and/or NDI. This risk was highest among those with Candida sepsis and/or meningitis.
Candida; Neonatal sepsis; Neurodevelopmental and Prematurity
Physicians and parents face significant uncertainties when making care decisions for extremely low birth weight (ELBW) infants. Many published estimates of death and developmental outcome are from well-funded university programs and may not reflect outcomes of infants from a variety of settings. The best estimates of the probabilities of death and severe disability combine local experience and published data. Objective: To describe the neurodevelopmental outcome of ELBW infants from centers of the ELBW Infant Follow-Up Group of the Vermont Oxford Network (VON) and to identify characteristics associated with severe disability.
Predefined measures of living situation, health and developmental outcome were collected at 18–24 months’ corrected age for infants born from July 1, 1998 to December 31, 2003 with birth weights of 401–1,000 g at 33 North American VON centers. Logistic regression was used to identify characteristics associated with severe disability.
6,198 ELBW infants were born and survived until hospital discharge; by the time of follow-up, 88 infants (1.4%) had died. Of the remaining 6,110 infants, 3,567 (58.4%) were evaluated. Severe disability occurred in 34% of the assessed infants. Multivariate logistic regression suggested cystic periventricular leukomalacia, congenital malformation and severe intraventricular hemorrhage were the characteristics most highly associated with severe disability. There were marked variations among the follow-up clinics in the attrition rate.
ELBW infants completing evaluation were at a high risk for severe disability. There are considerable differences among participating centers in attrition at follow-up. Further resources will be needed to study the effect of follow-up care for this group of infants.
Extremely low birth weight infant; Neurodevelopmental outcome; Severe disability; Vermont Oxford Network
To determine whether extremely low birth weight (ELBW) infants with bilateral compared to unilateral intraventricular hemorrhage (IVH) have worse neurodevelopmental outcomes at 18–22 months.
166 ELBW infants (<1000 g) admitted to a Cincinnati NICU from 1998–2005 with a head ultrasound showing Grade I–IV IVH and neurodevelopmental assessment at 18–22 months corrected age were included. Multivariable linear and logistic regression models were developed to determine the impact of laterality and grade of IVH and other clinical variables to predict scores on the Bayley Scales of Infant Development, Second Edition, Mental Development Index (MDI) and Psychomotor Development Index (PDI) and the combined outcome of neurodevelopmental impairment (NDI).
Infants with bilateral grade IV IVH had lower adjusted mean Bayley scores compared with infants with unilateral grade IV IVH. For grades I, II, and III IVH, bilaterality of IVH was not associated with lower mean Bayley scores. Infants with grade IV IVH had the highest odds of NDI. The probability of NDI increased with sepsis and postnatal steroid use.
ELBW infants with bilateral compared to those with unilateral grade IV IVH had worse neurodevelopmental outcomes. Infants with grades I–III IVH had similar outcomes whether they had unilateral or bilateral IVH.
premature; sepsis; steroids; Bayley; cognitive; motor
Both excess and insufficient levels of glucocorticoid in extremely low birth weight (ELBW) infants have been associated with adverse hospital outcomes, whereas excess glucocorticoid exposure has been associated with long-term adverse neurodevelopment. Our objective was to evaluate the relationship between neonatal cortisol concentrations and long-term outcomes of growth and neurodevelopment.
As part of a multicenter randomized trial of hydrocortisone treatment for prophylaxis of relative adrenal insufficiency, cortisol concentrations were obtained at 12 to 48 h of postnatal age and at days 5 to 7 on 350 intubated ELBW infants, of whom 252 survived and returned for neurodevelopmental follow-up at 18 to 22 months corrected age. Cortisol values from each time point were divided into quartiles. Growth and neurodevelopmental outcome were compared for each quartile.
Median cortisol value was 16.0 μg per 100 ml at baseline for all infants, and 13.1 μg per 100 ml on days 5 to 7 in the placebo group. Outcomes did not differ in each quartile between treatment and placebo groups. Low cortisol values at baseline or at days 5 to 7 were not associated with impaired growth or neurodevelopment at 18 to 22 months corrected age. High cortisol values were associated with an increase in cerebral palsy, related to the increased incidence of severe intraventricular hemorrhage (IVH) and periventricular leukomalacia.
Low cortisol concentrations were not predictive of adverse long-term outcomes. High cortisol concentrations, although predictive of short-term adverse outcomes such as IVH and periventricular leukomalacia, did not additionally predict adverse outcome. Further analysis into identifying factors that modulate cortisol concentrations shortly after birth could improve our ability to identify those infants who are most likely to benefit from treatment with hydrocortisone.
bronchopulmonary dysplasia; extremely preterm infants; hydrocortisone; outcomes of high-risk infants
To evaluate the neurodevelopmental outcomes of very preterm
(<30 weeks) infants who underwent tracheostomy.
Retrospective cohort study from 16 centers of the NICHD Neonatal
Research Network over 10 years (2001-2011). Infants who survived to at least
36 weeks (N=8,683), including 304 infants with tracheostomies, were studied.
Primary outcome was death or neurodevelopmental impairment (NDI, a composite
of one or more of: developmental delay, neurologic impairment, profound
hearing loss, severe visual impairment) at a corrected age of 18-22 months.
Outcomes were compared using multiple logistic regression. We assessed
impact of timing, by comparing outcomes of infants who underwent
tracheostomy before and after 120 days of life.
Tracheostomies were associated with all neonatal morbidities
examined, and with most adverse neurodevelopmental outcomes. Death or NDI
occurred in 83% of infants with tracheostomies and 40% of those without
[odds ratio (OR) adjusted for center 7.0 (95%CI, 5.2-9.5)]. After adjustment
for potential confounders, odds of death or NDI remained higher [OR 3.3
(95%CI, 2.4-4.6)], but odds of death alone were lower [OR 0.4 (95%CI,
0.3-0.7)], among infants with tracheostomies. Death or NDI was lower in
infants who received their tracheostomies before, rather than after, 120
days of life [adjusted OR 0.5 (95%CI, 0.3-0.9)].
Tracheostomy in preterm infants is associated with adverse
developmental outcomes, and cannot mitigate the significant risk associated
with many complications of prematurity. These data may inform counseling
about tracheostomy in this vulnerable population.
newborn; very low birth weight infant; neurodevelopmental impairment; tracheotomy; bronchopulmonary dysplasia; prematurity
Severe intracranial hemorrhage (ICH) is an important prognostic variable in extremely preterm (EPT) infants. We examined imaging and clinical variables that predict outcomes in EPT infants with severe ICH.
Retrospective analysis of 353 EPT infants with severe ICH. Outcomes were compared by examining: i) unilateral vs. bilateral ICH; and ii) presence vs. absence of hemorrhagic parenchymal infarction (HPI). Regression analyses identified variables associated with death or neurodevelopmental impairment (NDI).
Bilateral ICH and HPI had higher rates of adverse outcomes and were independently associated with death/NDI. HPI was the most important variable for infants of lower birth weight, and bilateral ICH for larger infants. For infants surviving to 36 weeks, shunt placement was most associated with death/NDI.
Bilateral ICH and the presence of HPI in EPT infants with severe ICH are associated with death/NDI, though the importance depends on birth weight and survival to 36 weeks.
intraventricular hemorrhage; neurodevelopmental impairment; extremely low birth weight; cranial ultrasound
We sought to determine the incidence of necrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP) in surviving extremely low-birth-weight (ELBW, <1000 g birth weight) infants and to establish the impact of NEC on outcomes by hospital discharge and at 18 to 22 months adjusted age in a large, contemporary, population-based practice.
Hospital outcome data for all ELBW infants born in the greater Cincinnati region from 1998 to 2009 were extracted from the National Institute of Child Health Neonatal Research Network Database. Neurodevelopmental outcome at 18 to 22 months was assessed using Bayley Scales of Infant Development-II scores for Mental Developmental Index and Psychomotor Developmental Index. Multivariable logistic regression was used and adjusted odds ratios reported to control for confounders.
From 1998 to 2009, ELBW infants accounted for 0.5% of the 352 176 live-born infants in greater Cincinnati. The incidence of NEC was 12%, with a 50% case-fatality rate. Death before discharge, morbid complications of prematurity and neurodevelopmental impairment were all increased among infants diagnosed with NEC. Infants with surgical NEC and SIP had a higher incidence of death, but long-term neurodevelopmental outcomes were not different comparing surviving ELBW infants with medical NEC, surgical NEC and SIP.
Although ELBW infants comprise a very small proportion of live-born infants, those who develop NEC and SIP are at an increased risk for death, morbid complications of prematurity and neurodevelopmental impairment. No significant differences in neurodevelopmental outcomes were observed between the medical and surgical NEC and SIP groups.
necrotizing enterocolitis; extremely low-birth-weight; neurodevelopmental outcome; Bayley scales of infant development
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
To test the hypothesis that increasing severity of the fetal inflammatory response would have a dose-dependent relationship with severe neurodevelopmental impairment (NDI) or death in extremely preterm infants.
We report 347 infants 23 to 28 weeks gestational age admitted to a tertiary neonatal intensive care unit between 2006 and 2008. The primary outcome was death or NDI at 18–22 month follow-up. Exposure status was defined by increasing stage of funisitis (stage 1: phlebitis; stage 2: arteritis with or without phlebitis; stage 3: subacute necrotizing funisitis) and severity of chorionic plate vasculitis (inflammation with or without thrombosis).
A fetal inflammatory response was detected in 110 placentas (32%). Severe NDI/death rate was higher in infants with subacute necrotizing funisitis compared with infants without placental/umbilical cord inflammation (60% vs. 35%; p<0.05). Among infants with stage 1 or 2 funisitis, the presence of any chorionic vasculitis was associated with higher rates of severe NDI/death (47% vs. 23%; p<0.05). After adjustment for confounding factors, only subacute necrotizing funisitis (RR: 1.87; 95% CI: 1.04 – 3.35; p=0.04) and chorionic plate vasculitis with thrombosis (RR: 2.21; 95% CI: 1.10 – 4.46; p=0.03) were associated with severe NDI/death.
Severe fetal inflammatory response characterized by subacute necrotizing funisitis and severe chorionic plate vasculitis with thrombosis are associated with severe NDI/death in preterm infants.
chorioamnionitis; infant; premature; prognosis; funisitis; chorionic plate vasculitis
This multicenter prospective study of invasive candidiasis (IC) was carried out to determine the risk factors for, incidence of, clinical and laboratory features, treatment and outcome of IC in infants of birth weight <1250 g.
Neonates <1250 g with IC and their matched controls (2:1) were followed longitudinally and descriptive analysis was performed. Survivors underwent neurodevelopmental assessment at 18 to 24 months corrected age. Neurodevelopmental impairment (NDI) was defined as blindness, deafness, moderate to severe cerebral palsy, or a score <70 on the Bayley Scales of Infant Development 2nd edition. Multivariable analyses were performed to determine risk factors for IC and predictors of mortality and NDI.
Cumulative incidence rates of IC were 4.2%, 2.2% and 1.5% for birth-weight categories <750 g, <1000 g, <1500 g, respectively. Forty nine infants with IC and 90 controls were enrolled. Necrotizing enterocolitis (NEC) was the only independent risk factor for IC (p = 0.03). CNS candidiasis occurred in 50% of evaluated infants, while congenital candidiasis occurred in 31%. Infants with CNS candidiasis had a higher mortality rate (57%) and incidence of deafness (50%) than the overall cohort of infants with IC. NDI (56% vs. 33%; p = 0.017) and death (45% vs. 7%; p = 0.0001) were more likely in cases than in controls, respectively. IC survivors were more likely to be deaf (28% vs. 7%; p = 0.01). IC independently predicted mortality (p = 0.0004) and NDI (p = 0.018).
IC occurred in 1.5% of VLBW infants. Preceding NEC increased the risk of developing IC. CNS candidiasis is under-investigated and difficult to diagnose, but portends a very poor outcome. Mortality, deafness and NDI were independently significantly increased in infants with IC compared to matched controls.
Invasive candidiasis; Neurodevelopmental outcome; Risk factors; Neonatal; Prematurity
Pulmonary hypertension is associated with bronchopulmonary dysplasia in extremely low birth weight (ELBW) infants and contributes to morbidity and mortality. The objective was to determine the prevalence of pulmonary hypertension among ELBW infants by screening echocardiography and evaluate subsequent outcomes.
All ELBW infants admitted to a regional perinatal center were evaluated for pulmonary hypertension with echocardiography at 4 weeks of age and subsequently if clinical signs suggestive of right-sided heart failure or severe lung disease were evident. Management was at discretion of the clinician, and infants were evaluated until discharge from the hospital or pre-discharge death occurred.
One hundred forty-five ELBW infants (birth weight: 755 ± 144 g; median gestational age: 26 weeks [interquartile range: 24–27]) were screened from December 2008 to February 2011. Overall, 26 (17.9%) were diagnosed with pulmonary hypertension at any time during hospitalization (birth weight: 665 ± 140 g; median gestational age: 26 weeks [interquartile range: 24–27]): 9 (6.2%) by initial screening (early pulmonary hypertension) and 17 (11.7%) who were identified later (late pulmonary hypertension). Infants with pulmonary hypertension were more likely to receive oxygen treatment on day 28 compared with those without pulmonary hypertension (96% vs 75%, P < .05). Of the 26 infants, 3 died (all in the late group because of cor pulmonale) before being discharged from the hospital.
Pulmonary hypertension is relatively common, affecting at least 1 in 6 ELBW infants, and persists to discharge in most survivors. Routine screening of ELBW infants with echocardiography at 4 weeks of age identifies only one-third of the infants diagnosed with pulmonary hypertension. Further research is required to determine optimal detection and intervention strategies.
premature infant; bronchopulmonary dysplasia; pulmonary hypertension
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
B-type natriuretic peptide (BNP) is a strong predictor of mortality in adult patients with various forms of pulmonary hypertension (PH) and may be a strong prognostic marker in extremely low birth weight (ELBW) infants with bronchopulmonary dysplasia (BPD) associated PH as well. We sought to assess the relationship between BNP levels and all-cause mortality in a cohort of ELBW infants with BPD and PH.
We retrospectively identified ELBW infants with BPD and PH who had serum BNP levels measured as part of routine clinical care in the neonatal intensive care unit. Peak serum BNP levels were correlated with survival to discharge or death.
Thirty-six ELBW infants (mean gestational age 26.0 ± 1.9 weeks and mean birth weight 740 ± 290 grams) with BPD and PH had available survival data and had serum BNP levels measured. Peak BNP level was significantly lower among infants who survived than among those who died (128 pg/ml, [IQR 23 to 463] vs. 997 pg/ml, [IQR 278 to 1770], P < 0.004). On multivariate Cox proportional hazard analysis, BNP predicted survival independent of age, gender, and BPD severity. Area under receiver operator characteristic analysis identified a BNP value of 220 pg/ml to have 90% sensitivity and 65% specificity in predicting mortality.
BNP estimation may be useful as a prognostic marker of all-cause mortality in ELBW infants with BPD associated PH.
Prematurity; Bronchopulmonary dysplasia; Prognostic factors; Outcome
Permissive hypercapnia is a ventilatory strategy used to prevent lung injury in ventilated extremely low birth weight (ELBW, birth weight ≤1000 g) infants. However, there is retrospective evidence showing that high CO2 is associated with brain injury.
The objective of this study was to compare brain white matter development at term-equivalent age in ELBW infants randomized to hypercapnic vs. normocapnic ventilation during the first week of life and in healthy non-ventilated term newborns.
Materials and Methods
Twenty-two ELBW infants from a randomized controlled trial were included in this study; 11 received hypercapnic (transcutaneous PCO2 [tcPCO2] 50–60 mm Hg) ventilation and 11 normocapnic (tcPCO2 35–45 mm Hg) ventilation during the first week of life while still intubated. In addition, 10 term healthy newborns served as controls. Magnetic resonance imaging (MRI) with diffusion tensor imaging (DTI) was performed at term-equivalent age for the ELBW infants and at approximately 2 weeks of age for the control infants. White matter injury on conventional MRI was graded in the ELBW and control infants using a scoring system adopted from literature. Tract-based spatial statistics (TBSS) was used to evaluate for differences in DTI measured fractional anisotropy (FA, spatially normalized to a customized template) among the ELBW and term control infants.
Conventional MRI white matter scores were not different (7.3 ± 1.7 vs. 6.9 ± 1.4, p=0.65) between the hypercapnic and normocapnic ELBW infants. TBSS analysis did not show significant differences (p<0.05, corrected) between the two ELBW infant groups, although before multiple comparisons correction, hypercapnic infants had many regions with lower FA (p<0.05, uncorrected) and no regions with higher FA (p<0.05, uncorrected) compared to normocapnic infants. When compared to the control infants, normocapnic ELBW infants had a few small regions with significantly lower FA, while hypercapnic ELBW infants had more widespread regions with significantly lower FA (p<0.05, fully corrected for multiple comparisons).
Normocapnic ventilation vs. permissive hypercapnia may be associated with improved white matter development at term-equivalent age in ELBW infants. This effect, however, was small and was not apparent on conventional MRI. Further research is needed using larger sample sizes to assess if permissive hypercapnic ventilation in ELBW infants is associated with worse white matter development.
To identify among extremely low birth weight (≤ 1000 grams) live births, the percent of infants who are unimpaired at 18–22 months corrected age.
Unimpaired outcome was defined as both Bayley-II MDI and PDI Scores ≥ 85, a normal neurological exam, normal vision, normal hearing and normal swallowing and ambulating. Outcomes at 18–22 months were determined for 5250 (86%) of 6090 ELBW inborn infants. Group comparisons were made and regression models were developed to identify factors associated with unimpaired outcome.
Of the 5250 infants whose outcome was known at 18 months, 850 (16%) were unimpaired, 1153 (22%) had mild impairments, 1147 (22%) had moderate to severe neurodevelopmental impairments and 2100 (40%) had died. Unimpaired survival rates varied by birth weight from <1% for infants ≤ 500 grams to 24% for infants 901–1000 grams for all live births. The regression model to predict unimpaired survival versus death or impairment for live births ( n=5250) identified that 25.3% of the variance was derived from infant factors present at birth including female gender, higher birth weight, singleton, and small for gestation, and less than 2% was explained either by maternal demographic factors or selected obstetric interventions. For the 3232 infants discharged from the NICU, the unimpaired survival rate was 26%. The regression model to predict unimpaired survival for discharged infants identified that most of the variance was derived from combined effects of major neonatal morbidities, neonatal interventions, and maternal demographics (15.7%) and only 8.5% was derived from infant factors present at birth.
Although <1% of ELBW live births ≤ 500 grams survive free of impairment at 18 months this increases to almost 24% for infants 901–1000 grams. Female gender, singleton, higher birth weight, absence of neonatal morbidities, private health insurance and White race increase the likelihood of unimpaired status.
Extremely low birth weight; outcomes; neurodevelopmental impairment