Outcome of extremely low birth weight infants (500 to 999 grams) over a 12-year period

Surgical Necrotizing Enterocolitis - Can We Predict the Need for Gastrostomy Tube Placement?

INTRODUCTION

Necrotizing enterocolitis (NEC) is a significant cause of morbidity and mortality among extremely premature infants. Approximately 50% of cases progress to surgery, frequently resulting in resection of necrotic bowel and ostomy creation. Premature neonates are at risk for bronchopulmonary dysplasia and feeding failure; surgery in these patients is higher risk. We evaluated the incidence of gastrostomy tube (GT) placement after ostomy reversal in surgical NEC to define a subset of patients who would benefit from concurrent ostomy reversal and GT placement.

METHODS

A single-center retrospective study of infants with surgical NEC requiring ostomy creation between 2007 and 2021 was performed.

RESULTS

Eighty patients met inclusion criteria. A GT was placed in 45/80 (56.3%), of which 3/45 (6.7%) were placed before, 20/45 (44.4%) concurrently with, and 22/45 (48.9%) after ostomy reversal. Between those who did and did not require GT placement, there were no significant differences in gestational age (27 versus 27 wk, P = 0.94) or birth weight (830 g versus 1055 g, P = 0.36). Hospital length of stay was longer in the GT group (128.2 versus 70.9 d, P < 0.0001). Time from ostomy reversal to hospital discharge was shorter when performed concurrently with GT (56 versus 77 d, P = 0.02). There were no differences in short-term or long-term GT related complications based on timing of GT placement.

CONCLUSIONS

GT placement occurred in approximately 50% of patients with surgical NEC and GT may be accomplished safely at the time of ostomy reversal thus reducing the need for an additional procedure.

Trends in the incidence and associated factors of late-onset sepsis associated with improved survival in extremely preterm infants born at 23-26 weeks' gestation: a retrospective study

Background

To investigate the trends in the incidence and associated factors of late-onset sepsis (LOS) associated with improved survival in extremely preterm infants.

Methods

Medical records of 364 infants who were born at 23–26 weeks’ gestation from 2000 to 2005 (period I, n = 124) and from 2006 to 2011 (period II, n = 240) were retrospectively reviewed. The infants were stratified into subgroups of 23–24 and 25–26 weeks’ gestation within each period, and survival, LOS rate, and clinical characteristics were analyzed. Multivariate logistic regression analyses were completed to identify the clinical factors associated with LOS.

Results

The survival rate of 75.8% during period I significantly improved to 85.4% during period II, especially in infants at 23–24 weeks’ gestation (55.1% vs. 78.1%, respectively). The LOS rate of 33.1% during period I significantly reduced to 15.8% during period II, especially in infants at 25–26 weeks’ gestation (32.0% vs. 8.9%, respectively). The LOS rate per 1000 hospital days of 4.0 during period I significantly reduced to 1.8 during period II. Candida presence reduced from 21.3% during period I to 4.7% during period II. In multivariate analyses, during period I, prolonged intubation, especially in infants at 25–26 weeks’ gestation, and necrotizing enterocolitis, especially in infants at 23–24 weeks’ gestation, were significantly associated with LOS.

Conclusions

Improved survival of infants at 23–24 weeks’ gestation was associated with a simultaneous reduction of LOS incidence in infants at 25–26 weeks’ gestation. Less-invasive assisted ventilation may be one of the details of improved perinatal and neonatal care that has contributed to lowering risk of infection or death among periviable infants.

Electronic supplementary material

The online version of this article (10.1186/s12887-018-1130-y) contains supplementary material, which is available to authorized users.

Short-term costs of preeclampsia to the United States health care system

BACKGROUND

Preeclampsia is a leading cause of maternal morbidity and mortality and adverse neonatal outcomes. Little is known about the extent of the health and cost burden of preeclampsia in the United States.

OBJECTIVE

This study sought to quantify the annual epidemiological and health care cost burden of preeclampsia to both mothers and infants in the United States in 2012.

STUDY DESIGN

We used epidemiological and econometric methods to assess the annual cost of preeclampsia in the United States using a combination of population-based and administrative data sets: the National Center for Health Statistics Vital Statistics on Births, the California Perinatal Quality Care Collaborative Databases, the US Health Care Cost and Utilization Project database, and a commercial claims data set.

RESULTS

Preeclampsia increased the probability of an adverse event from 4.6% to 10.1% for mothers and from 7.8% to 15.4% for infants while lowering gestational age by 1.7 weeks (P < .001). Overall, the total cost burden of preeclampsia during the first 12 months after birth was $1.03 billion for mothers and $1.15 billion for infants. The cost burden per infant is dependent on gestational age, ranging from $150,000 at 26 weeks gestational age to $1311 at 36 weeks gestational age.

CONCLUSION

In 2012, the cost of preeclampsia within the first 12 months of delivery was $2.18 billion in the United States ($1.03 billion for mothers and $1.15 billion for infants), and was disproportionately borne by births of low gestational age.

Skeletal assessment and secular changes in knee development: a radiographic approach

OBJECTIVES

The purpose of this study is to conduct an analysis of ossification patterns in the distal femoral, proximal tibial, and proximal fibular epiphyses, and the patella. The results generated from this analysis will be compared with previous standards published by Elgenmark () and Garn et al. () to determine if clinical and skeletal age assessment standards should be updated for contemporary Americans.

MATERIALS AND METHODS

Using the Pediatric Radiology Interactive Atlas (Patricia), a total of 1,317 epiphyses were scored for presence or absence from radiographs of 1,056 white individuals born in or after 1990. Statistical modeling of epiphyseal appearance was conducted for all major percentiles, including the 5th and 95th percentiles through logistic regression.

RESULTS

Compared with Elgenmark () and Garn et al. (), our data suggest that the distal femoral and proximal tibial epiphyses show overall earlier ossification, while the proximal fibular epiphysis shows later ossification. When examining the pooled sex 50th percentile for our data, we found that ossification timing differences are 1.2 weeks earlier in the distal femoral epiphysis, 2.1 weeks earlier in the proximal tibial epiphysis, and 1.4 years later in the proximal fibular epiphysis.

DISCUSSION

The epiphyses that appear early in life, for example the distal femoral epiphysis, require gestational age information to accurately estimate appearance times. There are considerable differences between the ossification timing patterns presented in this study and those of previous standards, which did not include gestational ages. Several factors may explain the observed differences in the epiphyses of the knee including: the availability of gestational age information, the analysis of longitudinal versus cross-sectional data, differences in socioeconomic status and prenatal care, and secular change. KEYWORDS age estimation, growth standards, ossification, skeletal maturation, subadult/juvenile growth.

Screening Cranial Imaging at Multiple Time Points Improves Cystic Periventricular Leukomalacia Detection

OBJECTIVE

The aim of this study is to determine whether the cystic periventricular leukomalacia (cPVL) detection rate differs between imaging studies performed at different time points.

DESIGN

We retrospectively reviewed the prospectively collected data of 31,708 infants from the NICHD Neonatal Research Network. Inclusion criteria were infants < 1,000 g birth weight or < 29 weeks' gestational age who had cranial imaging performed using both early criterion (cranial ultrasound [CUS] < 28 days chronological age) and late criterion (CUS, magnetic resonance imaging, or computed tomography closest to 36 weeks postmenstrual age [PMA]). We compared the frequency of cPVL diagnosed by early and late criteria.

RESULTS

About 664 (5.2%) of the 12,739 infants who met inclusion criteria had cPVL using either early or late criteria; 569 using the late criterion, 250 using the early criterion, and 155 patients at both times. About 95 (14.3%) of 664 cPVL cases seen on early imaging were no longer visible on repeat screening closest to 36 weeks PMA. Such disappearance of cPVL was more common in infants < 26 weeks' gestation versus infants of 26 to 28 weeks' gestation (18.5 vs. 11.5%; p = 0.013).

CONCLUSIONS

Cranial imaging at both < 28 days chronological age and closest to 36 weeks PMA improves cPVL detection, especially for more premature infants.

A psychoneuroimmunologic examination of cumulative perinatal steroid exposures and preterm infant behavioral follow-up

PURPOSE

This study's aim was to explore relationships between preterm infant behavioral outcomes and maternal/infant glucocorticoid (dexamethasone [DEX]) treatments using a psychoneuroimmunologic approach. Research questions were (a) do relationships exist between infant cumulative perinatal steroid (PNS) exposure and child behavioral problems? and (b) do maternal/infant characteristics (e.g., immune markers and biophysiologic stressors) influence these relationships?

METHODS

The convenience sample comprised 45 mother-child dyads in which the children (mean age 8 years ± 2.3) had been born at a mean postconceptional age of 28 weeks (± 4.2). We used the Child Behavior Checklist (CBCL) to assess behavior, the Clinical Risk Index for Babies (CRIB) to score stress at birth, and retrospective record review to identify additional perinatal factors (PNS dosage, sepsis, and maternal and infant complete blood counts near delivery).

RESULTS

Children were dichotomized into high (> 0.2 mg/kg; n = 20) versus low-no (≤0.2 mg/kg; n = 25) PNS exposure groups. Significant relationships existed between CBCL Total Problems score and sepsis, PNS exposure, timing of initial PNS, and infant length percentile at discharge. Competence problems were significantly associated with PNS, neonatal intensive care unit (NICU) infant length percentile, CRIB score, sepsis, retinopathy of prematurity, hearing deficit, and immunity markers (i.e., maternal lymphocyte percentage and infant band/seg ratio). Children in the higher PNS group exhibited more behavioral problems (e.g., withdrawn, attention, conduct, social, and rule breaking problems), but there were no significant differences. The findings are reassuring regarding long-term effects of this PNS dose on preterm infant behavioral outcomes.

The impact of wealth on the cognitive development of children who were preterm infants

PURPOSE

: The purpose of this study was to explore the influence wealth has on cognitive development in 2-year-old children who were born preterm, and to determine whether racial/ethnic differences in wealth explained disparities in cognitive development.

SUBJECTS

: A nationally representative sample of 1400 children who were born between 22 and 36 weeks' gestation.

DESIGN

: Cohort study.

METHODS

: Secondary data analysis of the Early Childhood Longitudinal Survey-Birth Cohort (ECLS-B). The ECLS-B was a prospective national longitudinal study of infants born in the United States during the calendar year 2001 drawn from birth certificates in the United States.

MAIN OUTCOMES

: The impact wealth (parental homeownership and investments) had on cognitive development at 2 years and whether wealth eliminated the cognitive disparity seen between white, African American, and Hispanic children.

PRINCIPAL RESULTS

: Wealth (homeownership and investments) did not have an independent effect on cognitive development, but it did eliminate the disparity between white children and African American children (P ≥ .05). However, wealth did not eliminate the disparity in cognitive development between white children and Hispanic children. Hispanic children scored 3.91 points lower than white children (P ≤ .001).

CONCLUSION

: In contrast to other follow-up studies showing persistent differences in cognitive development between white children and African American children, this study found that wealth indicators attenuated the difference. Wealth may be a more accurate proxy for socioeconomic status in studying factors influencing cognitive outcomes in children born preterm than just using measures such as maternal education and income. In future follow-up studies of multiracial preterm children, indicators that represent wealth should be included for an accurate representation of social economic status.

Retinopathy of prematurity in southern Taiwan: a 10-year tertiary medical center study

BACKGROUND/PURPOSE

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness. This retrospective study investigated ROP, including incidence, demographic information,risk factors, treatments, and refractive outcomes, in southern Taiwan over a 10-year period.

METHODS

The authors retrieved the National Cheng Kung University Hospital database between the years 2000 and 2009 for newborns with a gestational age less than 32 weeks and/or with a birth weight less than 1500 g who had been screened for ROP. We recorded sex, birth weight, gestational age, in-hospital versus out-of-hospital birth, paternal and maternal ages, whether there were multiple gestations, parity, Apgar scores, length of hospital stay, risk factors, presence and severity of ROP and whether it was treated, and refraction at the last visit. Regression analyses were performed to identify risk factors for ROP.

RESULTS

A total of 503 live births were included. ROP was identified in 190 (37.8%) and met criteria for treatment in 59 (11.7%).ROP was diagnosed as stage 1, 2, 3, 4, and 5 in 61 (12.1%), 36 (7.2%), 81 (16.1%), 11 (2.2%), and 1 (0.2%) infant, respectively. Lower birth weight and younger gestational age were risk factors for greater severity of ROP (p < 0.001). Of the 167 with extremely low birth weight (<1000 g), 118 (70.7%) had ROP and 49 (29.3%) required treatment. On univariate analysis, low birth weight, younger gestational age, and risk factors such as respiratory distress syndrome, chronic lung disease, patent ductus arteriosus, surfactant usage, indomethacin usage, sepsis, upper gastrointestinal bleeding, blood transfusion, and necrotizing enterocolitis were associated with ROP. Multivariate logistic regression analysis showed that only lower birth weight was a significant and independent risk factor for ROP. Myopia (76%)and anisometropia (28%)were common in advanced ROP.

CONCLUSION

Low birth weight is a major risk factor for ROP. Infants with extremely low birth weight had a higher risk of severe ROP. Common ocular sequelae of advanced ROP were myopia and anisometropia.

Diffusion tensor imaging of the cortical plate and subplate in very-low-birth-weight infants

BACKGROUND

Many intervention studies in preterm infants aim to improve neurodevelopmental outcome, but short-term proxy outcome measurements are lacking. Cortical plate and subplate development could be such a marker.

OBJECTIVE

Our aim was to provide normal DTI reference values for the cortical plate and subplate of preterm infants.

MATERIALS AND METHODS

As part of an ongoing study we analysed diffusion tensor imaging (DTI) images of 19 preterm infants without evidence of injury on conventional MRI, with normal outcome (Bayley-II assessed at age 2), and scanned in the first 4 days of life. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in the frontal and temporal subplate and cortical plate were measured in single and multiple voxel regions of interest (ROI) placed on predefined regions.

RESULTS

Using single-voxel ROIs, statistically significant inverse correlation was found between gestational age (GA) and FA of the frontal (r = -0.5938, P = 0.0058) and temporal (r = -0.4912, P = 0.0327) cortical plate. ADC values had a significant positive correlation with GA in the frontal (r = 0.5427, P = 0.0164) and temporal (r = 0.5540, P = 0.0138) subplate.

CONCLUSION

Diffusion tensor imaging allows in vivo exploration of the evolving cortical plate and subplate. We provide FA and ADC values of the subplate and cortical plate in very-low-birth-weight (VLBW) infants with normal developmental outcome that can be used as reference values.

Meta-analysis of neurobehavioral outcomes in very preterm and/or very low birth weight children

OBJECTIVE

Sequelae of academic underachievement, behavioral problems, and poor executive function (EF) have been extensively reported for very preterm (<or=33 weeks' gestation) and/or very low birth weight (VLBW) (<or=1500 g) children. Great variability in the published results, however, hinders the field in studying underlying dysfunctions and developing intervention strategies. We conducted a quantitative meta-analysis of studies published between 1998 and 2008 on academic achievement, behavioral functioning, and EF with the aim of providing aggregated measures of effect size for these outcome domains.

METHODS

Suitable for inclusion were 14 studies on academic achievement, 9 studies on behavioral problems, and 12 studies on EF, which compared a total of 4125 very preterm and/or VLBW children with 3197 term-born controls. Combined effect sizes for the 3 outcome domains were calculated in terms of Cohen's d. Q-test statistics were performed to test homogeneity among the obtained effect sizes. Pearson's correlation coefficients were calculated to examine the impact of mean birth weight and mean gestational age, as well as the influence of mean age at assessment on the effect sizes for academic achievement, behavioral problems, and EF.

RESULTS

Combined effect sizes show that very preterm and/or VLBW children score 0.60 SD lower on mathematics tests, 0.48 SD on reading tests, and 0.76 SD on spelling tests than term-born peers. Of all behavioral problems stacked, attention problems were most pronounced in very preterm and/or VLBW children, with teacher and parent ratings being 0.43 to 0.59 SD higher than for controls, respectively. Combined effect sizes for parent and teacher ratings of internalizing behavior problems were small (<0.28) and for externalizing behavior problems negligible (<0.09) and not significant. Combined effect sizes for EF revealed a decrement of 0.57 SD for verbal fluency, 0.36 SD for working memory, and 0.49 SD for cognitive flexibility in comparison to controls. Mean age at assessment was not correlated with the strength of the effect sizes. Mathematics and reading performance, parent ratings of internalizing problems, teacher ratings of externalizing behavior, and attention problems, showed strong and positive correlations with mean birth weight and mean gestational age (all r values > 0.51).

CONCLUSIONS

Very preterm and/or VLBW children have moderate-to-severe deficits in academic achievement, attention problems, and internalizing behavioral problems and poor EF, which are adverse outcomes that were strongly correlated to their immaturity at birth. During transition to young adulthood these children continue to lag behind term-born peers.

Retinopathy of prematurity in extremely premature infants

INTRODUCTION

The incidence and severity of retinopathy of prematurity (ROP) in extremely premature infants have not been reported since publication of the Early Treatment of ROP study results. The survival rate of these infants continues to increase. We sought to determine the characteristics of ROP in a group of surviving infants <25 weeks estimated gestational age (EGA) at birth compared to a group 25 to 27 weeks EGA at birth.

METHODS

Retrospective review of infants born prior to 27 weeks EGA between January 2003 and July 2007 at a level-3 nursery at a regional academic medical center.

RESULTS

A total of 231 medical records were reviewed and found to have analyzable data. Of 79 infants <25 weeks EGA, 69 (87%) developed ROP, compared to 95 of 152 (62%) infants 25 to 27 weeks EGA. Type 1 ROP developed in 23% of infants in the <25 weeks EGA group, compared to 9% of infants in the 25 to 27 weeks EGA group. There was no difference in mean postmenstrual age when type 1 ROP was diagnosed. Lower birth weight predicted increased risk of type 1 ROP in the 25 to 27 weeks EGA group, but not in the <25 weeks EGA group.

CONCLUSIONS

Extremely premature infants are more likely to develop ROP and type 1 ROP, but the incidence may be lower than previously reported. Birth weight may not influence the incidence of type 1 ROP in this group of infants. Type 1 ROP does not develop at an earlier postmenstrual age in the extremely premature infant.

Clinical report--Antenatal counseling regarding resuscitation at an extremely low gestational age

The anticipated delivery of an extremely low gestational age infant raises difficult questions for all involved, including whether to initiate resuscitation after delivery. Each institution caring for women at risk of delivering extremely preterm infants should provide comprehensive and consistent guidelines for antenatal counseling. Parents should be provided the most accurate prognosis possible on the basis of all the factors known to affect outcome for a particular case. Although it is not feasible to have specific criteria for when the initiation of resuscitation should or should not be offered, the following general guidelines are suggested. If the physicians involved believe there is no chance for survival, resuscitation is not indicated and should not be initiated. When a good outcome is considered very unlikely, the parents should be given the choice of whether resuscitation should be initiated, and clinicians should respect their preference. Finally, if a good outcome is considered reasonably likely, clinicians should initiate resuscitation and, together with the parents, continually reevaluate whether intensive care should be continued. Whenever resuscitation is considered an option, a qualified individual, preferably a neonatologist, should be involved and should be present in the delivery room to manage this complex situation. Comfort care should be provided for all infants for whom resuscitation is not initiated or is not successful.

Unimpaired outcomes for extremely low birth weight infants at 18 to 22 months

OBJECTIVE

The goal was to identify, among extremely low birth weight (<or=1000 g) live births, the proportion of infants who were unimpaired at 18 to 22 months of corrected age.

METHODS

Unimpaired outcome was defined as Bayley Scales of Infant Development II scores of >or=85, normal neurologic examination findings, and normal vision, hearing, swallowing, and walking. Outcomes were determined for 5250 (86%) of 6090 extremely low birth weight inborn infants.

RESULTS

Of the 5250 infants whose outcomes were known at 18 months, 850 (16%) were unimpaired, 1153 (22%) had mild impairments, 1147 (22%) had moderate/severe neurodevelopmental impairments, and 2100 (40%) had died. Unimpaired survival rates varied according to birth weight, from <1% for infants <or=500 g to 24% for infants 901 to 1000 g. The regression model to predict unimpaired survival versus death or impairment for live births (N = 5250) indicated that 25.3% of the variance was derived from infant factors present at birth, including female gender, higher birth weight, singleton birth. The regression model to predict unimpaired survival for discharged infants indicated that most of the variance was derived from combined effects of major neonatal morbidities, neonatal interventions, and maternal demographic features (15.7%) and only 8.5% was derived from infant factors present at birth.

CONCLUSIONS

Although <1% of live-born infants of <or=500 g survive free of impairment at 18 months, this increases to almost 24% for infants of 901 to 1000 g. Female gender, singleton birth, higher birth weight, absence of neonatal morbidities, private health insurance, and white race increase the likelihood of unimpaired status.

Neurodevelopmental outcome of the premature infant

Advances in antenatal medicine and neonatal intensive care have successfully resulted in improved survival rates of preterm infants. These improvements have been most dramatic in infants born extremely low birth weight (ELBW, <or=1000 g) and at the limits of viability (22 to 25 weeks). But improvements in survival have not been accompanied by proportional reductions in the incidence of disability in this population. Thus, survival is not an adequate measure of success in these infants who remain at high risk for neurodevelopmental and behavioral morbidities. There is now increasing evidence of sustained adverse outcomes into school age and adolescence, not only for ELBW infants but for infants born late preterm.

Stability of neuromotor outcomes at 18 and 30 months of age after extremely low birth weight status

BACKGROUND

Extremely low birth weight (< or =1000 g) children have increased rates of cerebral palsy and other abnormal neurologic findings.

OBJECTIVE

To investigate the stability of neuromotor findings between 18 and 30 months' adjusted age in extremely low birth weight infants. METHODS. Seven hundred nineteen extremely low birth weight infants with assessments at 18 and 30 months' adjusted age were included in this analysis. At each visit a neurologic examination, the modified gross motor function classification system, and the Bayley Scales of Infant Development II were administered. Logistic regression models were constructed to assess neonatal factors and neuromotor function at 18 months of age associated with stability in neuromotor function.

RESULTS

Eighty-four percent of the children had agreement in neurologic/motor function at both visits. However, classification changed from normal to abnormal in 6% and from abnormal to normal in 10%. Diagnosis of cerebral palsy was consistent for 91% of the children, and the gross motor function classification system score was consistent for 83%. In multivariate models, factors associated with decreased severity or absence of cerebral palsy diagnosis at 30 months of age were higher gestational age, no periventricular leukomalacia or severe intraventricular hemorrhage, and a gross motor function classification system score of 0 (normal) at the 18-month visit, whereas factors associated with a new cerebral palsy diagnosis at 30 months of age were postnatal steroid use, periventricular leukomalacia or severe intraventricular hemorrhage, a gross motor function classification system score of > or =1 at 18 months of age, and asymmetrical limb movement at 18 months of age.

CONCLUSIONS

Stability of neurologic diagnosis in 84% and cerebral palsy in 91% of the children is reassuring. However, for a significant percentage of children, the neurologic diagnosis changes between 18 and 30 months of age. The diagnosis of cerebral palsy may be delayed in some infants until an older adjusted age.

A comparison of executive function in very preterm and term infants at 8 months corrected age

BACKGROUND

Executive function (EF) emerges in infancy and continues to develop throughout childhood. Executive dysfunction is believed to contribute to learning and attention problems in children at school age. Children born very preterm are more prone to these problems than their full-term peers.

AIM

To compare EF in very preterm and full-term infants at 8 months after expected date of delivery.

SUBJECTS

37 very preterm infants without identified disabilities, and 74 gender and age matched healthy full-term infants. The very preterm infants were all </=32 weeks gestation and <1250 g birthweight.

OUTCOME MEASURES

EF tasks which measured working memory, inhibition of distraction, and planning at 8 months after expected date of delivery.

RESULTS

The very preterm infants performed significantly more poorly than the full-term infants on all measures of executive function. No significant differences were found between very preterm and full-term infants on any of potentially confounding variables of, infant temperament, maternal education, family income and maternal psychological wellbeing. Very preterm infants had significantly lower scores on the Mental Development Index (MDI) and Psychomotor Development Index (PDI) on the Bayley Scales of Infant Development (BSID II), however when this was partialled out the differences in EF scores remained. Medical complications, lower birthweight and lower gestation age were all found to adversely affect the performance of very preterm infants on executive function tasks.

CONCLUSION

Very preterm infants performed more poorly than full-term infants on measures of EF. Further follow up studies are required to investigate whether EF measures in infancy can predict learning and attention outcome at school age.

Surfactant-replacement therapy for respiratory distress in the preterm and term neonate

Respiratory failure secondary to surfactant deficiency is a major cause of morbidity and mortality in preterm infants. Surfactant therapy substantially reduces mortality and respiratory morbidity for this population. Secondary surfactant deficiency also contributes to acute respiratory morbidity in late-preterm and term neonates with meconium aspiration syndrome, pneumonia/sepsis, and perhaps pulmonary hemorrhage; surfactant replacement may be beneficial for these infants. This statement summarizes indications, administration, formulations, and outcomes for surfactant-replacement therapy. The impact of antenatal steroids and continuous positive airway pressure on outcomes and surfactant use in preterm infants is reviewed. Because respiratory insufficiency may be a component of multiorgan dysfunction, preterm and term infants receiving surfactant-replacement therapy should be managed in facilities with technical and clinical expertise to administer surfactant and provide multisystem support.

Fractional anisotropy in white matter tracts of very-low-birth-weight infants

BACKGROUND

Advances in neonatal intensive care have not yet reduced the high incidence of neurodevelopmental disability among very-low-birth-weight (VLBW) infants. As neurological deficits are related to white-matter injury, early detection is important. Diffusion tensor imaging (DTI) could be an excellent tool for assessment of white-matter injury.

OBJECTIVE

To provide DTI fractional anisotropy (FA) reference values for white-matter tracts of VLBW infants for clinical use.

MATERIALS AND METHODS

We retrospectively analysed DTI images of 28 VLBW infants (26-32 weeks gestational age) without evidence of white-matter abnormalities on conventional MRI sequences, and normal developmental outcome (assessed at age 1-3 years). For DTI an echoplanar sequence with diffusion gradient (b = 1,000 s/mm(2)) applied in 25 non-collinear directions was used. We measured FA and apparent diffusion coefficient (ADC) of different white-matter tracts in the first 4 days of life.

RESULTS

A statistically significant correlation was found between gestational age and FA of the posterior limb of the internal capsule in VLBW infants (r = 0.495, P<0.01).

CONCLUSION

Values of FA and ADC were measured in white-matter tracts of VLBW infants. FA of the pyramidal tracts measured in the first few days after birth is related to gestational age.

Trends in cerebral palsy among infants of very low birthweight (<1500 g) or born prematurely (<32 weeks) in 16 European centres: a database study

BACKGROUND

The risk of cerebral palsy, the commonest physical disability of children in western Europe, is higher in infants of very low birthweight (VLBW)--those born weighing less than 1500 g--and those from multiple pregnancies than in infants of normal birthweight. An increasing proportion of infants from both of these groups survive into childhood. This paper describes changes in the frequency and distribution of cerebral palsy by sex and neurological subtype in infants with a birthweight below 1000 g and 1000-1499 g in the period 1980-96.

METHODS

A group of 16 European centres, Surveillance of Cerebral Palsy in Europe, agreed a standard definition of cerebral palsy and inclusion and exclusion criteria. Data for children with cerebral palsy born in the years 1980-96 were pooled. The data were analysed to describe the distribution and prevalence of cerebral palsy in VLBW infants. Prevalence trends were expressed as both per 1000 livebirths and per 1000 neonatal survivors.

FINDINGS

There were 1575 VLBW infants born with cerebral palsy; 414 (26%) were of birthweight less than 1000 g and 317 (20%) were from multiple pregnancies. 1426 (94%) had spastic cerebral palsy, which was unilateral (hemiplegic) in 336 (24%). The birth prevalence fell from 60.6 (99%CI 37.8-91.4) per 1000 liveborn VLBW infants in 1980 to 39.5 (28.6-53.0) per 1000 VLBW infants in 1996. This decline was related to a reduction in the frequency of bilateral spastic cerebral palsy among infants of birthweight 1000-1499 g. The frequency of cerebral palsy was higher in male than female babies in the group of birthweight 1000-1499 g (61.0 [53.8-68..2] vs 49.5 [42.8-56.2] per 1000 livebirths; p=0.0025) but not in the group of birthweight below 1000 g.

INTERPRETATION

These data from a large population base provide evidence that the prevalence of cerebral palsy in children of birthweight less than 1500 g has fallen, which has important implications for parents, health services, and society.

Surfactant era (1990-2002) 2-year outcomes of infants less than 1500 g from a Community Level 3 Neonatal Intensive Care Unit

OBJECTIVE

To report Bayley scores of 572 twenty-four-month corrected age infants whose birth weights (BWs) were less than 1500 g cared for in a Community Level 3 Neonatal Intensive Care Unit (NICU) between 1990 and 2002 when surfactant was routinely used.

STUDY DESIGN

Survival, "normal" defined as both Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI)>84, MDI>69 and MDI>84 were analyzed by gestational age (GA) and BW. Comparisons were made between infants born pre- and post-1996 when high-frequency oscillatory ventilation came into frequent use, Medicaid and non-Medicaid infants, multiples and singletons, outborn and inborn infants, boys and girls and infants with intrauterine growth retardation (IUGR) and those appropriate for gestational age (AGA).

RESULTS

There was a correlation between GA and BW and improving outcomes. Scores do not approach those of normal standardization sample populations (60% for "normal", 68% for MDI>84 and 95% for MDI>69) until 1400 g and 30 weeks. Medicaid, outborn and IUGR infants, and boys did worse in some aspects.

CONCLUSION

There was a correlation between both GA and BW and improving outcomes. Availability of these developmental data on a laminated pocket card can facilitate presentation of outcome experience to families by pediatric and obstetric caregivers.

The role of chronic hypoxia in the development of neurocognitive abnormalities in preterm infants with bronchopulmonary dysplasia

Bronchopulmonary dysplasia is the most common pulmonary morbidity in preterm infants and is associated with chronic hypoxia. Animal studies have demonstrated structural, neurochemical and functional alterations due to chronic hypoxia in the developing brain. Long-term impairments in visual-motor, gross and fine motor, articulation, reading, mathematics, spatial memory and attention skills are prevalent in survivors of bronchopulmonary dysplasia, and impairments appear to correlate with the severity of hypoxia. However, due to the simultaneous occurrence of multiple neurodevelopmental risk factors, a primary or potentiating role for chronic hypoxia in these impairments has yet to be conclusively established.

Developmental regulation of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor subunit expression in forebrain and relationship to regional susceptibility to hypoxic/ischemic injury. II. Human cerebral white matter and cortex

This report is the second of a two-part evaluation of developmental differences in alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR) subunit expression in cell populations within white matter and cortex. In part I, we reported that, in rat, developmental expression of Ca2+-permeable (GluR2-lacking) AMPARs correlated at the regional and cellular level with increased susceptibility to hypoxia/ischemia (H/I), suggesting an age-specific role of these receptors in the pathogenesis of brain injury. Part II examines the regional and cellular progression of AMPAR subunits in human white matter and cortex from midgestation through early childhood. Similarly to the case in the rodent, there is a direct correlation between selective vulnerability to H/I and expression of GluR2-lacking AMPARs in human brain. For midgestational cases aged 20-24 postconceptional weeks (PCW) and for premature infants (25-37 PCW), we found that radial glia, premyelinating oligodendrocytes, and subplate neurons transiently expressed GluR2-lacking AMPARs. Notably, prematurity represents a developmental window of selective vulnerability for white matter injury, such as periventricular leukomalacia (PVL). During term (38-42 PCW) and postterm neonatal (43-46 PCW) periods, age windows characterized by increased susceptibility to cortical injury and seizures, GluR2 expression was low in the neocortex, specifically on cortical pyramidal and nonpyramidal neurons. This study indicates that Ca2+-permeable AMPAR blockade may represent an age-specific therapeutic strategy for potential use in humans. Furthermore, these data help to validate specific rodent maturational stages as appropriate models for evaluation of H/I pathophysiology.

Health service utilisation of a regional cohort of very preterm infants over the first 2 years of life

AIM

Very preterm infants represent major consumers of health services following neonatal discharge. We examined the health service utilisation of a regional cohort of very preterm infants over the first 2 years of life, including the association with neurodevelopmental outcome.

METHODS

A regionally based 2-year cohort of 100 very preterm infants along with a comparison sample of 104 full term control infants matched for sex, time and place of birth were recruited. Perinatal and social background factors that predispose very preterm infants to increased risk of subsequent general practitioner (GP) and hospital service use were identified. At 2 years, all children underwent a neurodevelopmental assessment, Bayley Scales of Infant Development (BSID-II). Details of children's medical contacts obtained by parent interview were cross-checked against GP and hospital records/databases.

RESULTS

Very preterm infants had a similar number of GP visits to term infants but more outpatient hospital visits. Fifty-three (55%) very preterm infants were admitted to hospital on 131 occasions compared with 26 (26%) term infants on 37 occasions (p<0.001). The main reason for hospitalisation in the preterm cohort was respiratory disorder. The frequency of hospital admissions was significantly related to birthweight (P=0.01), gestational age (P<0.001) and the number of people living in the family household (P=0.02). No associations were found between hospital admission and neurodevelopment at 2 years.

CONCLUSION

Very preterm infants had higher rates of hospital admissions and visits than term infants unrelated to neurodevelopmental outcome at 2 years of age. These findings highlight that very preterm birth is associated with ongoing health morbidity.

Risks for low intellectual performance related to being born small for gestational age are modified by gestational age

OBJECTIVE

We sought to study whether the association between being born small for gestational age and risk for low intellectual performance was modified by gestational age.

METHODS

A population-based cohort study was conducted of 352,125 boys who were born between 28 and 43 completed weeks of gestation from 1973 to 1981 in Sweden. Risk for low intellectual performance at military conscription, estimated as odds ratios with 95% confidence intervals was measured.

RESULTS

Compared with men who were born preterm (28-36 weeks) and had normal birth weight for gestational age, men who were born preterm and had a very low birth weight for gestational age were not at increased risk for low intellectual performance. In contrast, men who were born preterm with a very short birth length or a very small head circumference for gestational age faced a near doubled risk for low intellectual performance compared with their appropriate peers. Among men who were born at term (37-41 weeks), risk for low intellectual performance was increased among those with very or moderately small birth weight, birth length, or head circumference for gestational age.

CONCLUSIONS

During early stages of gestation, growth in length and head circumference may be more important for intellectual development than weight increase. Future studies on size at birth and intellectual performance should consider also including anthropometric measurements other than birth weight.

Usefulness of an early neurofunctional assessment in predicting neurodevelopmental outcome in very low birthweight infants

OBJECTIVE

To evaluate whether early neurofunctional assessment may be useful in predicting neurodevelopmental outcome in children of very low birth weight (VLBW).

DESIGN

Observational longitudinal study.

SETTINGS

Northern Italy.

PATIENTS

A total of 250 VLBW children (129 boys, 121 girls) born consecutively 1996-1999.

MAIN OUTCOME MEASURES

Neurodevelopment at 36 months of chronological age, classified in accordance with the classification of Tardieu and the International classification of functioning.

RESULTS

Of the infants exhibiting normal neurodevelopment (n = 183) or major dysfunction (n = 17) at 3 months of corrected age, 72% and 94% respectively did not change their score during the study. Minor dysfunctions at 3 months of corrected age were transient in 17 (34%) children. After adjustment for neonatal variables, neurodevelopment at 3 months of corrected age remained predictive of dysfunction at 36 months (odds ratio = 4.33, 95% confidence interval 2.05 to 9.12). If the results for the normal and minor dysfunction groups were pooled, the predictive qualities of the 3 month neurofunctional assessment were: sensitivity 0.5, specificity 0.99, positive predictive value 0.94, negative predictive value 0.93.

CONCLUSION

Early neurofunctional evaluation may be useful in predicting later neurodevelopmental outcome in VLBW children.

Racial and gender differences in the viability of extremely low birth weight infants: a population-based study

OBJECTIVE

The purpose of this study is to provide a race- and gender-specific model for predicting 1-year survival rates for extremely low birth weight (ELBW) infants by using population-based data.

METHODS

Birth and death certificates were analyzed for all children (N = 5076) with birth weights between 300 g and 1000 g who were born in Florida between 1996 and 2000. Semiparametric, multivariate, logistic regression analysis was used to model 1-year survival probabilities as a function of birth weight, gestational age, mother's race, and infant's gender. Estimated survival rates among different race/gender groups were compared by using odds ratios (ORs).

RESULTS

One-year survival rates for 5076 ELBW infants born between 1996 and 2000 did not change during the 5-year period (60-62%). The survival rate at < or = 500 g was < or = 14% (n = 716). Survival rates at 501 to 600 g and 601 to 700 g were 36% and 62%, respectively. The survival rate reached > 85% for infants of > 800 g. Modeling indicated a survival advantage for female infants, compared with male infants (OR: 1.7; 95% confidence interval: 1.5-1.9), and for black infants, compared with white infants (OR: 1.3; 95% confidence interval: 1.1-1.5). Black female infants had 2.1 greater odds of survival than did white male infants.

CONCLUSIONS

This population-based study highlights the significant race and gender differences in 1-year survival rates for ELBW infants, as well as the interactions of these 2 factors. These findings can assist obstetricians and neonatologists not only in the care of ELBW infants but also in frank discussions with families.

Artificial reproduction technologies (RTs) - all the way to the artificial womb?

In this paper, I argue that the development of an artificial womb is already well on its way. By putting together pieces of information arising from new scientific advances in different areas, (neo-natal care, gynecology, embryology, the human genome project and computer science), I delineate a distinctive picture, which clearly suggests that the artificial womb may become a reality sooner than we may think. Currently, there is a huge gap between the first stages of gestation (using in vitro fertilization) and the 22nd week (inside the womb). At the present time this gap seems an insurmountable barrier for fully developing a fetus outside a natural womb - a notion better known as ectogenesis. The history of science however, suggests that impenetrable barriers are such only temporarily. It is just a matter of time (and due research) until someone - intentionally or by chance - accesses the right answer and finds a way to overcome existing obstacles. Despite misgivings that the case of the artificial womb presents too many barriers, it would be naive to suppose things would happen any differently. I observe in this paper, that it is time to acknowledge the consequences of new developments in different areas of scientific research which are leading to the advent of an artificial womb; and I modestly suggest that we might initiate a discussion on this topic now, while we have still enough time to decide what we may want and why.

Umbilical cord levels of interleukin-1 receptor antagonist and neonatal outcome

BACKGROUND

Previous studies indicate that there may be infant gender differences in cytokine expression associated with differences in neonatal morbidity.

OBJECTIVE

We tested the hypothesis that umbilical cord interleukin-1 receptor antagonist (IL-1ra) correlates with infant gender and neonatal outcome in preterm infants.

STUDY DESIGN

IL-1ra was measured in cord blood taken from 58 preterm infants (33 males, 25 females) with gestational age less than 32 weeks. Receiver operating characteristics (ROC) curve were used for identifying IL-1ra values with high sensitivity and specificity for neonatal morbidity and adverse outcome, i.e., death or survival with severe intraventricular hemorrhage or periventricular leukomalacia.

RESULTS

In the female infants, but not the male infants, cord IL-1ra values correlated with postnatal depression, expressed as Apgar scores at 1 min (correlation coefficient, r(s); p value: -0.542; 0.005), 5 min (-0.571; 0.018), and 10 min (-0.442; 0.035); and postnatal age at intubation (-0.799; 0.001). The ROC area under the curve (AUC) was 0.735 for adverse outcome (p=0.013), and 0.683 for bronchopulmonary dysplasia (p=0.021) when all infants were included. However, there was a significant gender difference in the ROC curve for adverse outcome (p=0.026), with AUC 0.640 (p=0.240) in males and AUC 0.929 (p=0.008) in females. Above a chosen cutoff at 13,500 ng/l for IL-1ra cord the sensitivity and specificity for predicting adverse outcome was 100 and 81%, respectively in females versus 50 and 84% in males.

CONCLUSION

Increased levels of cord IL-1ra levels are associated with neonatal morbidity and adverse outcome in preterm infants. Comparable levels of IL-1ra have different predictive value depending on infant gender.

Early brain injury in premature newborns detected with magnetic resonance imaging is associated with adverse early neurodevelopmental outcome

OBJECTIVE

To determine the neurodevelopmental outcome of prematurely born newborns with magnetic resonance imaging (MRI) abnormalities.

STUDY DESIGN

A total of 89 prematurely born newborns (median age 28 weeks postgestation) were studied with MRI when stable for transport to MRI (median age, 32 weeks postgestation); 50 newborns were studied again near term age (median age, 37 weeks). Neurodevelopmental outcome was determined at 18 months adjusted age (median) using the Mental Development Index (Bayley Scales Infant Development II) and a standardized neurologic exam.

RESULTS

Of 86 neonatal survivors, outcome was normal in 51 (59%), borderline in 22 (26%), and abnormal in 13 (15%). Moderate/severe MRI abnormalities were common on the first (37%) and second (32%) scans. Abnormal outcome was associated with increasing severity of white matter injury, ventriculomegaly, and intraventricular hemorrhage on MRI, as well as moderate/severe abnormalities on the first (relative risk [RR] = 5.6; P = .002) and second MRI studies (RR = 5.3; P = .03). Neuromotor abnormalities on neurologic examination near term age (RR = 6.5; P = .04) and postnatal infection (RR = 4.0; P = .01) also increased the risk for abnormal neurodevelopmental outcome.

CONCLUSIONS

In premature newborns, brain abnormalities are common on MRI early in life and are associated with adverse neurodevelopmental outcome.

Neurodevelopmental outcomes of premature infants treated with inhaled nitric oxide

BACKGROUND

Chronic lung disease and severe intraventricular hemorrhage or periventricular leukomalacia in premature infants are associated with abnormal neurodevelopmental outcomes. In a previous randomized, controlled, single-center trial of premature infants with the respiratory distress syndrome, inhaled nitric oxide decreased the risk of death or chronic lung disease as well as severe intraventricular hemorrhage and periventricular leukomalacia. We hypothesized that infants treated with inhaled nitric oxide would also have improved neurodevelopmental outcomes.

METHODS

We conducted a prospective, longitudinal follow-up study of premature infants who had received inhaled nitric oxide or placebo to investigate neurodevelopmental outcomes at two years of corrected age. Neurologic examination, neurodevelopmental assessment, and anthropometric measurements were made by examiners who were unaware of the children's original treatment assignment.

RESULTS

A total of 138 children (82 percent of survivors) were evaluated. In the group given inhaled nitric oxide, 17 of 70 children (24 percent) had abnormal neurodevelopmental outcomes, defined as either disability (cerebral palsy, bilateral blindness, or bilateral hearing loss) or delay (no disability, but one score of less than 70 on the Bayley Scales of Infant Development II), as compared with 31 of 68 children (46 percent) in the placebo group (relative risk, 0.53; 95 percent confidence interval, 0.33 to 0.87; P=0.01). This effect persisted after adjustment for birth weight and sex, as well as for the presence or absence of chronic lung disease and severe intraventricular hemorrhage or periventricular leukomalacia. The improvement in neurodevelopmental outcome in the group given inhaled nitric oxide was primarily due to a 47 percent decrease in the risk of cognitive impairment (defined by a score of less than 70 on the Bayley Mental Developmental Index) (P=0.03).

CONCLUSIONS

Premature infants treated with inhaled nitric oxide have improved neurodevelopmental outcomes at two years of age.

Outcome of low birthweight in China: a 16-year longitudinal study

AIM

To compare the growth and neurodevelopment of low-birthweight (LBW) and normal-birthweight (control) infants born and raised in China.

DESIGN

Prospective cohort study.

SUBJECTS AND SETTING

203 LBW (1200-2499 g) and 71 control (> or =2500 g) infants born at two Shanghai hospitals in 1983 did not differ for date of birth, gender, parental occupation, parental weight and age. LBW <10th centile at > or =37 wk gestation was defined as small for gestational age (SGA, n=102). LBW at < 37 wk gestation was defined as preterm (n=101).

MAIN OUTCOME MEASURES

Weight, height, head circumference, Gesell developmental quotient (DQ), Wechsler intelligence quotient (IQ), and scholastic achievement score.

RESULTS

Of the 274 enrolled subjects, 234 (85%) returned at 6 mo, 135 (49%) at 6 y, and 104 (38%) at 16 y. SGA, preterm, and control subjects did not differ in rates of follow-up or baseline characteristics. However, SGA and preterm were lower than control subjects in weight and head circumference through 16 y, height through 4 y, DQ through 3 y, IQ at 5 and 16 y, and scholastic achievement at 16 y. Catch-up to growth in the control group, defined as >3rd centile, and normal IQ, defined as > or =85, were both more common among preterm than SGA subjects.

CONCLUSIONS

Adolescents in China with birthweights of 1200-2499 g, and particularly those who were SGA, lag behind peers with birthweights >2500 g in physical growth, cognitive capacity, and school achievement. The findings suggest that LBW adolescents in China today represent a population in need of evaluation and support.

Emotional regulation and its impact on development in extremely low birth weight infants

The purposes of this study were to compare the Bayley Scales of Infant Development (BSID-II) scores at 8 and 18-22 months adjusted age of a cohort of 47 extremely low birth weight infants and to determine whether there was an association between changes in test scores and infant behavior as measured by the Behavioral Rating Scale of the BSID-II at 18-22 months adjusted age. Psychomotor Developmental Index scores did not differ between the two testing points (p = .17), whereas the Mental Developmental Index (MDI) scores dropped significantly (p = .006). Emotional regulation and low household income were both significantly associated with changes in MDI scores (p = .001 and p = .002, respectively). After adjusting for household income, the association between emotional regulation and changes in MDI scores remained significant (p = .02). Results suggest that infant behavioral characteristics, as well as family socioeconomic status, can adversely affect developmental outcome at 18-22 months adjusted age.

Early death, morbidity, and need of treatment among extremely premature infants

OBJECTIVE

To determine outcomes, in terms of perinatal and early death, need for treatment, and morbidity at the time of discharge home, among extremely preterm infants.

DESIGN

A prospective observational study of all infants with a gestational age (GA) of 22 to 27 completed weeks or a birth weight of 500 to 999 g who were born in Norway in 1999 and 2000.

RESULTS

Of 636 births, 174 infants (27%) were stillborn or died in the delivery room, 86 (14%) died in the NICU, and 376 (59%) were discharged from the hospital. The risk of being registered as stillborn or not being resuscitated increased with decreasing GA below 25 weeks. The survival rates for all births and for infants admitted to a NICU were, respectively, 0% for <23 weeks, 16% and 39% for 23 weeks, 44% and 60% for 24 weeks, 66% and 80% for 25 weeks, 72% and 84% for 26 weeks, 82% and 93% for 27 weeks, and 69% and 90% for >27 weeks. For the survivors, days of mechanical ventilation decreased from a median of 37 days to 3 days and the proportion in need of oxygen at 36 weeks' postconceptional age decreased from 67% to 26% at 23 and 27 weeks' GA, respectively. At 40 weeks' postconceptional age, the respective figures were 11% and 6%. The proportion with retinopathy of prematurity (ROP) requiring treatment decreased from 33% for GA of 23 weeks to 0% for >25 weeks. Periventricular hemorrhage of more than grade 2 occurred for 6% of the survivors and significant periventricular leukomalacia occurred for 5%, with no significant association with GA. The proportion of survivors without severe neurosensory or pulmonary morbidity increased from 44% for 23 weeks' to 86% for 27 weeks' GA. Apart from ROP, the morbidity rate was not associated with GA.

CONCLUSIONS

The survival rate was high and the morbidity rate at discharge home was low in the present study, compared with previous population-based studies. With the exception of ROP, the morbidity rates among the survivors were not higher at the lowest GAs, possibly because withholding treatment was considered more acceptable for the most immature infants. The need for intensive care increased markedly for survivors with the lowest GAs.

Improved survival rates with increased neurodevelopmental disability for extremely low birth weight infants in the 1990s

BACKGROUND

Advances in perinatal care have resulted in increased survival rates for extremely low birth weight children. We sought to examine the relative changes in rates of survival and neurodevelopmental impairment at 20 months of corrected age among 500- to 999-g birth weight infants born at our perinatal center during 2 periods, before and after the introduction of surfactant therapy in 1990.

METHODS

Four hundred ninety-six infants with birth weights of 500 to 999 g were born at our perinatal center during period I (1982-1989) (mean body weight: 762 g; mean gestational age: 25.8 weeks) and 682 during period II (1990-1998) (mean body weight: 756 g; mean gestational age: 25.5 weeks). Rates of death and survival with and without neurodevelopmental impairment at 20 months of corrected age for the 2 periods were compared with logistic regression analyses, with adjustment for gestational age.

RESULTS

Survival rates increased from 49% during period I to 67% during period II. Neonatal morbidity rates also increased during period II, including rates of sepsis (from 37% to 51%), periventricular leukomalacia (from 2% to 7%), and chronic lung disease, defined as oxygen dependence at 36 weeks of corrected age (from 32% to 43%). Rates of severe cranial ultrasound abnormalities were similar (22% vs 22%). Among children monitored, the rate of neurologic abnormalities, including cerebral palsy, increased from 16% during period I to 25% during period II and the rate of deafness increased from 3% to 7%. The overall rate of neurodevelopmental impairment (major neurosensory abnormality and/or Bayley Mental Developmental Index score of <70) increased from 26% to 36%. Compared with period I, in period II there were decreased rates of death (odds ratio [OR]: 0.3; 95% confidence interval [CI]: 0.2-0.4) and increased rates of survival with impairment (OR: 2.3; 95% CI: 1.7-3.3) but also increased rates of survival without impairment (OR: 1.7; 95% CI: 1.3-2.2). Compared with period I, for every 100 infants with birth weights of 500 to 999 g born in period II, 18 additional infants survived, of whom 7 were unimpaired and 11 were impaired.

CONCLUSIONS

The improved survival rates in the 1990s occurred with an increased risk of significant neurodevelopmental impairment. Prospective parents of extremely low birth weight infants should be advised of this substantial risk, to facilitate decision-making in the delivery room.

The efficacy of clinical strategies to reduce nosocomial sepsis in extremely low birth weight infants

The aim of this study was to evaluate the efficacy of clinical strategies to reduce nosocomial sepsis (NS) in extremely low birth weight infants (ELBWI) less than 1,000 g. Data from the period before (P1, 1995-2000) and after (P2, 2001-2002) implementation of the strategies were collected and analyzed. The intervention strategies included restriction of antibiotic therapy, less use of invasive procedures such as umbilical vessel catheterization and endotracheal intubation, establishment of guidelines for hand-washing, infant handling, and central intravascular line management. NS was defined as positive blood cultures in symptomatic patients after the third day of life with the use of antibiotics for more than 5 days. Although the gestational age (GA) and birth weight (BW) were significantly lower in P2 (GA 26.7 +/-2.1 wk; BW 796 +/-130 g) compared to P1 (GA 27.2 +/-1.6 wk; BW 857 +/-121 g), the incidence of NS decreased significantly from 70% (69/99) in P1 to 17% (24/71) in P2 with the implementation of the intervention strategies. The coagulase negative Staphylococcus infection was also significantly reduced from 34% in P1 to 11% in P2. The implementation of the clinical strategies was quite effective in reducing the incidence of NS in ELBWI.

Changes in mortality and morbidities among infants born at less than 25 weeks during the post-surfactant era

OBJECTIVES

To compare mortality and death or major morbidity (DOMM) among infants <25 weeks estimated gestational age (EGA) born during two post-surfactant era time periods.

STUDY DESIGN AND PATIENTS

Comparative cohort study of very low birthweight (501-1500 g) infants <25 weeks EGA in the NICHD Neonatal Research Network born during two post-surfactant era time periods (group I, 1991-1994, n=1408; group II, 1995-1998, n=1348). Perinatal and neonatal factors were compared, and group related mortality and DOMM risk were evaluated.

RESULTS

Mortality was higher for group I (63.1% v 56.7%; p=0.0006). Antenatal steroids (ANS) and antenatal antibiotics (AABX), surfactant (p<0.0001), and bronchopulmonary dysplasia (p=0.0008) were more prevalent in group II. In a regression model that controlled for basic and delivery factors only, mortality risk was greater for group I than for group II (odds ratio (OR) 1.4, 95% confidence interval (CI) 1.2 to 1.7); the addition of AABX and surfactant, or ANS (OR 0.97, 95% CI 0.79 to 1.2) to the model appeared to account for this difference. There was no difference in DOMM (86.8% v 88.4%; p=0.2), but risk was lower for group I in regression models that included ANS (OR 0.70, 95% CI 0.52 to 0.94).

CONCLUSION

Survival to discharge was more likely during the more recent period because of group differences in ANS, AABX, and surfactant. However, this treatment shift may reflect an overall more aggressive management approach. More consistent application of treatment has led to improving survival of <25 week EGA infants during the post-surfactant era, but possibly at the cost of greater risk of major in-hospital morbidities.

Adverse neurodevelopmental outcomes among extremely low birth weight infants with a normal head ultrasound: prevalence and antecedents

OBJECTIVE

Severe abnormalities of the head ultrasound (HUS) are important predictors of cerebral palsy (CP) and mental retardation, and a normal HUS usually ensures the absence of major impairments. With the increasing survival of extremely low birth weight (ELBW) infants (birth weight <1000 g), the prognostic significance of a normal HUS may differ. This study examined the prevalence of and risk factors for CP and impaired mental development among ELBW infants with a normal HUS.

METHODS

Study infants were ELBW infants who were cared for in Neonatal Research Network centers in the years 1995-1999, had a normal early and late HUS, survived to discharge, and returned for follow-up assessments at 18 to 22 months' corrected age. The outcomes of interest were a score <70 on the Bayley Scales of Infant Development-II Mental Developmental Index (MDI) and CP. Risk factors included maternal demographics; infant characteristics; and interventions or morbidities related to the lung, infection, and nutrition. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). A time-oriented approach was used to select variables for inclusion in logistic models.

RESULTS

Of 1749 infants with a normal early and late HUS (performed at a mean age of 6 and 47 days, respectively), 1473 (84%) returned for follow-up assessment. Infants had a birth weight of 792 +/- 134 g (mean +/- SD) and gestational age of 26 +/- 2 weeks. Rates of CP and MDI <70 were 9.4% and 25.3%, respectively, and 29.2% of infants had either CP or MDI <70. In multivariate analyses, factors associated with CP were male gender (OR: 1.8; 95% CI: 1.2-2.6), multiple birth, (OR: 1.6; 95% CI: 1.1-2.5), decreasing birth weight (OR: 1.3 for each 100-g decrease; 95% CI: 1.1-1.5), pneumothorax (OR: 2.3; 95% CI: 1.2-4.4), and days of conventional ventilation (OR: 1.2 for each additional 10 days; 95% CI: 1.1-1.3). With the exception of pneumothorax, these same factors were associated with MDI <70, in addition to less maternal education (OR: 1.4; 95% CI: 1.0-1.9) and Medicaid or lack of coverage for maternal insurance (OR: 1.7; 95% CI: 1.2-2.4).

CONCLUSIONS

Nearly 30% of ELBW infants with a normal HUS had either CP or a low MDI. Risk factors that are associated with this high rate of adverse outcomes include pneumothorax, prolonged exposure to mechanical ventilation, and educational and economic disadvantage. Improvements in pulmonary care to reduce duration of ventilation and avoid air leaks might improve neurodevelopmental outcome for ELBW infants.

Non-human primate models of neonatal brain injury

Nonhuman primate species have been selectively used in the scientific investigation of adult and newborn neurological diseases. The rhesus monkey has been utilized in models of term asphyxial insults, accurately reflecting the mechanisms and neuropathology demonstrated in the newborn human infant. More recently, a premature baboon model developed for evaluation of bronchopulmonary dysplasia has been applied to the investigation of cerebral development and injury, revealing high similarity in neuropathology to the premature human infant. Given the differences in the outcomes of neuroprotective therapies between lower order species, such as the rat, and human trials in disorders such as stroke, nonhuman primate models may provide an invaluable resource for safety and efficacy testing before trials in human newborns. This article summarizes both models of brain injury. The histologic findings from the models are compared with neuropathological studies in human infants.

Trends in severe brain injury and neurodevelopmental outcome in premature newborn infants: the role of cystic periventricular leukomalacia

OBJECTIVES

To determine if the incidence of sonographically detected cystic periventricular leukomalacia (PVL) and periventricular hemorrhagic infarction (PVHI) have changed over the past decade and to determine if a decline in cystic PVL was associated with a change in neurodevelopmental outcome.

STUDY DESIGN

Premature newborn infants admitted to our intensive care nursery from 1992 to 2002 were identified in a comprehensive nursery database. Premature newborn infants had routine neurosonography by means of a standardized protocol. Infants weighing < or =1500 g at birth surviving to nursery discharge were enrolled in a nursery follow-up clinic.

RESULTS

Adjusting for gestational age, there was a significant decrease in cystic PVL from 1992 to 2002 (P=.003) without a concurrent decrease in PVHI (P=0.5). Cystic PVL and PVHI accounted for only 9 of the 28 cases of cerebral palsy and 12 of 90 cases of abnormal Developmental Scores in infants weighing <1500 g at birth. The decline in cystic PVL was not associated with improved developmental outcome from 1992 to 2002.

CONCLUSIONS

The incidence of cystic PVL declined significantly from 1992 to 2002 at our center. Cystic PVL was detected by ultrasound in a minority of infants with abnormal neurodevelopmental outcome, indicating that other forms of cerebral injury account for the majority of abnormal neurodevelopmental outcomes in premature newborn infants.

Nutrition of very low birth weight infants fed human milk with or without supplemental trace elements: a randomized controlled trial

BACKGROUND

Very low birth weight infants (<1500 g) have high nutritional needs. Deficiencies of minerals, trace elements (especially zinc) may develop as a result of rapid growth, low body stores and low content of these substances in human milk We hypothesized that fortification of human milk might prevent deficiencies.

METHODS

Prospective, randomized trial to evaluate mineral, trace element, thyroid status and growth of infants fed human milk fortified with different amounts of calcium, phosphorus and protein, with (BMF) or without (FM 85) trace elements. Sixty-two infants, 1000 to 1499 g birth weight, were randomized. Minerals and trace elements in serum, red blood cells and human milk and alkaline phosphatase activity, TSH, T4 and FT4 in serum were measured once until the fifth day and at 3 and 6 weeks of life. Clinical course and anthropometric measurements were recorded.

RESULTS

Intake of zinc, copper, manganese, calcium, phosphorus and magnesium was higher in the BMF group (P < 0.001). Serum zinc concentrations <0.49 mg/L occurred in 12% of the FM 85 group and 7% of the BMF group at 6 weeks (not significant). Median alkaline phosphatase activity was 436/379 IU/L in the FM 85/BMF group at 6 weeks (P < 0.01). The FM 85 group showed a higher weight gain (P < 0.05), possibly because of higher caloric (P < 0.01) and protein intake (P < 0.05) at 3 weeks.

CONCLUSIONS

Zinc deficiency was rare. Elevated intake of calcium, phosphorus and zinc was associated with lower serum alkaline phosphatase activity but did not influence serum zinc concentration.

Incidence of retinopathy of prematurity from 1996 to 2000: analysis of a comprehensive New York state patient database

OBJECTIVE

To determine the current incidence of retinopathy of prematurity (ROP) in New York state.

DESIGN

Population-based cohort study.

PARTICIPANTS

Newborn infants (15 691) with initial hospital length of stay >28 days and date of discharge from January 1, 1996, to December 31, 2000. Subjects were identified from the New York Statewide Planning and Research Cooperative System (SPARCS) database, which contains information about every patient hospitalized in New York during this period.

METHODS

Demographic and clinical information about eligible infants was abstracted by searching the SPARCS database. Patients with a discharge diagnosis of ROP or who underwent laser retinal photocoagulation, scleral buckle, or pars plana vitrectomy were identified by searching for appropriate discharge and procedure codes. Incidence of ROP in the study population was determined and analyzed on the basis of birth weight.

MAIN OUTCOME MEASURES

Incidence of any ROP, laser photocoagulation, scleral buckle, and pars plana vitrectomy in study population.

RESULTS

On the basis of SPARCS coding, the overall incidence of any ROP among all newborn infants in New York state during the study period was 0.2% (2284 of 1 167 427), or 1 in 511. The incidence of any ROP in the study population of newborns with initial hospital length of stay >28 days was 20.3% (2152 of 10 596) among infants with birth weight <1500 g and 27.3% (1839 of 6745) among infants with birth weight <1200 g. Among study patients with any ROP, the proportion who underwent laser photocoagulation during initial hospital stay was 9.5% (218 of 2284), and the proportion who underwent scleral buckle or vitrectomy surgery was 0.5% (12 of 2284). Seventeen study newborns with birth weight > or =2000 g had a discharge diagnosis of ROP, although none of these patients required laser or incisional surgery during hospitalization.

CONCLUSIONS

This study involves the largest known cohort of newborns that has been analyzed for ROP. The incidence of ROP in this study is lower than results from previous multicenter clinical trials. However, the diagnosis of ROP in 17 study newborns with birth weight > or =2000 g deserves further investigation and may have implications for ROP screening protocols.

Hospital survival of very-low-birth-weight neonates from 1977 to 2000

OBJECTIVE

To determine patterns of survival for very low birth weight (VLBW, birth weight 501 to 1500 g) neonates over 23 years.

STUDY DESIGN

Data for 4873 VLBW neonates born from 1977 to 2000 were divided into five epochs. The primary outcome was survival to hospital discharge. Birth weight-specific survival rates were estimated by race and gender for each epoch. Presence of comorbidities and congenital anomalies, delivery mode, and provision of artificial ventilation were investigated to determine whether they could explain observed survival patterns.

RESULTS

From 1977 to 1995, survival increased from 50.2% to 81.0% as the proportion of VLBW neonates receiving artificial ventilation rose from 59.0% to 80.9%. Survival was unchanged between 1990 to 1995 and 1996 to 2000. Black females maintained a survival advantage over the entire study period. Survival improved for neonates with congenital anomalies over time, but had little impact on race/gender survival patterns. Survival patterns also could not be explained by comorbidity status, delivery mode, or access to artificial ventilation.

CONCLUSION

The survival advantage of VLBW black females persists and remains unexplained.

Fetal infants: the fate of 4172 infants with birth weights of 401 to 500 grams--the Vermont Oxford Network experience (1996-2000)

OBJECTIVE

Improvement in the survival of extremely low birth weight infants requires that we evaluate the limits of our care and assess the impact of treatment on a population of infants who previously rarely survived.

METHODS

A review was conducted of demographic and clinical data of infants who had birth weight 401 to 500 g and were entered in the Vermont Oxford Network Database between 1996 and 2000.

RESULTS

A total of 4172 infants who weighed 401-500 g (mean gestational age: 23.3 +/- 2.1 weeks) were born at 346 participating centers. Overall, 17% survived until discharge. A total of 2186 (52%) died in the delivery room (DR), and 1986 (48%) were admitted to a neonatal intensive care unit (NICU). Compared with infants who died in the DR, infants who survived the DR and were admitted to the NICU were more likely to be female (58% vs 49%), to be small for gestational age (56% vs 11%), to have received prenatal steroids (61% vs 12%), and to have been delivered by cesarean section (55% vs 5%). Thirty-six percent of NICU admissions survived to discharge. Mean gestational age of the 690 NICU survivors was 25.3 +/- 2.0 weeks. These survivors experienced significant morbidity in the NICU.

CONCLUSIONS

An appreciable number of these marginally viable fetal infants survive. They experienced a high rate of serious morbidities while in the NICU. There is very little information about long-term outcomes, as the medical and developmental status of few of these infants has been followed carefully. Parents should be made aware of the high incidence of serious problems, and concerted efforts should be made to follow the status of these infants.