Use of term reference infants in assessing the developmental outcome of extremely preterm infants: lessons learned in a multicenter study

OBJECTIVE

Extremely preterm (EP) impairment rates are likely underestimated using the Bayley III norm-based thresholds scores and may be better assessed relative to concurrent healthy term reference (TR) infants born in the same hospital.

STUDY DESIGN

Blinded, certified examiners in the Neonatal Research Network (NRN) evaluated EP survivors and a sample of healthy TR infants recruited near the 2-year assessment age.

RESULTS

We assessed 1452 EP infants and 183 TR infants. TR-based thresholds showed higher overall EP impairment than Bayley norm-based thresholds (O.R. = 1.86; [95% CI 1.56-2.23], especially for severe impairment (36% vs. 24%; p ≤ 0.001). Difficulty recruiting TR patients at 2 years extended the study by 14 months and affected their demographics.

CONCLUSION

Impairment rates among EP infants appear to be substantially underestimated from Bayley III norms. These rates may be best assessed by comparison with healthy term infants followed with minimal attrition from birth in the same centers.

CLINICALTRIALS

GOV ID

Term Reference (under the Generic Database Study): NCT00063063.

Delayed-interval delivery in multiple gestation pregnancies: neonatal mortality, morbidity, and development

OBJECTIVE

Delayed-interval delivery (DID) is the delivery of the first fetus in a multiple gestation pregnancy without prompt delivery of the remaining fetus(es). We aimed to assess infant outcomes of DID.

STUDY DESIGN

We performed a retrospective cohort study of infants born 22-28 weeks' gestation or weighing 401-1500 g. DID was defined as a passage of >24 h between the birth of firstborn and retained infants. Rates of mortality, morbidity, and developmental outcomes were compared within DID multiples, to other multiples not born by DID, and all infants in the Generic Database and follow-up datasets (excluding DID-born).

RESULTS

DID-born multiples were younger and smaller than other multiples. Retained infants had no significantly different rates of mortality and morbidities compared to their firstborn counterparts, apart from less bronchopulmonary dysplasia.

CONCLUSIONS

DID showed no evidence of harm and a potential benefit of decreased bronchopulmonary dysplasia mediated by increased gestational age and birthweight.

Hydrocortisone to Improve Survival without Bronchopulmonary Dysplasia

BACKGROUND

Bronchopulmonary dysplasia is a prevalent complication after extremely preterm birth. Inflammation with mechanical ventilation may contribute to its development. Whether hydrocortisone treatment after the second postnatal week can improve survival without bronchopulmonary dysplasia and without adverse neurodevelopmental effects is unknown.

METHODS

We conducted a trial involving infants who had a gestational age of less than 30 weeks and who had been intubated for at least 7 days at 14 to 28 days. Infants were randomly assigned to receive either hydrocortisone (4 mg per kilogram of body weight per day tapered over a period of 10 days) or placebo. Mandatory extubation thresholds were specified. The primary efficacy outcome was survival without moderate or severe bronchopulmonary dysplasia at 36 weeks of postmenstrual age, and the primary safety outcome was survival without moderate or severe neurodevelopmental impairment at 22 to 26 months of corrected age.

RESULTS

We enrolled 800 infants (mean [±SD] birth weight, 715±167 g; mean gestational age, 24.9±1.5 weeks). Survival without moderate or severe bronchopulmonary dysplasia at 36 weeks occurred in 66 of 398 infants (16.6%) in the hydrocortisone group and in 53 of 402 (13.2%) in the placebo group (adjusted rate ratio, 1.27; 95% confidence interval [CI], 0.93 to 1.74). Two-year outcomes were known for 91.0% of the infants. Survival without moderate or severe neurodevelopmental impairment occurred in 132 of 358 infants (36.9%) in the hydrocortisone group and in 134 of 359 (37.3%) in the placebo group (adjusted rate ratio, 0.98; 95% CI, 0.81 to 1.18). Hypertension that was treated with medication occurred more frequently with hydrocortisone than with placebo (4.3% vs. 1.0%). Other adverse events were similar in the two groups.

CONCLUSIONS

In this trial involving preterm infants, hydrocortisone treatment starting on postnatal day 14 to 28 did not result in substantially higher survival without moderate or severe bronchopulmonary dysplasia than placebo. Survival without moderate or severe neurodevelopmental impairment did not differ substantially between the two groups. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01353313.).

Preterm Neuroimaging and School-Age Cognitive Outcomes

BACKGROUND AND OBJECTIVES

Children born extremely preterm are at risk for cognitive difficulties and disability. The relative prognostic value of neonatal brain MRI and cranial ultrasound (CUS) for school-age outcomes remains unclear. Our objectives were to relate near-term conventional brain MRI and early and late CUS to cognitive impairment and disability at 6 to 7 years among children born extremely preterm and assess prognostic value.

METHODS

A prospective study of adverse early and late CUS and near-term conventional MRI findings to predict outcomes at 6 to 7 years including a full-scale IQ (FSIQ) <70 and disability (FSIQ <70, moderate-to-severe cerebral palsy, or severe vision or hearing impairment) in a subgroup of Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial enrollees. Stepwise logistic regression evaluated associations of neuroimaging with outcomes, adjusting for perinatal-neonatal factors.

RESULTS

A total of 386 children had follow-up. In unadjusted analyses, severity of white matter abnormality and cerebellar lesions on MRI and adverse CUS findings were associated with outcomes. In full regression models, both adverse late CUS findings (odds ratio [OR] 27.9; 95% confidence interval [CI] 6.0-129) and significant cerebellar lesions on MRI (OR 2.71; 95% CI 1.1-6.7) remained associated with disability, but only adverse late CUS findings (OR 20.1; 95% CI 3.6-111) were associated with FSIQ <70. Predictive accuracy of stepwise models was not substantially improved with the addition of neuroimaging.

CONCLUSIONS

Severe but rare adverse late CUS findings were most strongly associated with cognitive impairment and disability at school age, and significant cerebellar lesions on MRI were associated with disability. Near-term conventional MRI did not substantively enhance prediction of severe early school-age outcomes.

Neuroimaging and neurodevelopmental outcome in extremely preterm infants

BACKGROUND

Extremely preterm infants are at risk for neurodevelopmental impairment (NDI). Early cranial ultrasound (CUS) is usual practice, but near-term brain MRI has been reported to better predict outcomes. We prospectively evaluated MRI white matter abnormality (WMA) and cerebellar lesions, and serial CUS adverse findings as predictors of outcomes at 18 to 22 months' corrected age.

METHODS

Early and late CUS, and brain MRI were read by masked central readers, in a large cohort (n = 480) of infants <28 weeks' gestation surviving to near term in the Neonatal Research Network. Outcomes included NDI or death after neuroimaging, and significant gross motor impairment or death, with NDI defined as cognitive composite score <70, significant gross motor impairment, and severe hearing or visual impairment. Multivariable models evaluated the relative predictive value of neuroimaging while controlling for other factors.

RESULTS

Of 480 infants, 15 died and 20 were lost. Increasing severity of WMA and significant cerebellar lesions on MRI were associated with adverse outcomes. Cerebellar lesions were rarely identified by CUS. In full multivariable models, both late CUS and MRI, but not early CUS, remained independently associated with NDI or death (MRI cerebellar lesions: odds ratio, 3.0 [95% confidence interval: 1.3-6.8]; late CUS: odds ratio, 9.8 [95% confidence interval: 2.8-35]), and significant gross motor impairment or death. In models that did not include late CUS, MRI moderate-severe WMA was independently associated with adverse outcomes.

CONCLUSIONS

Both late CUS and near-term MRI abnormalities were associated with outcomes, independent of early CUS and other factors, underscoring the relative prognostic value of near-term neuroimaging.

Respiratory outcomes of the surfactant positive pressure and oximetry randomized trial (SUPPORT)

OBJECTIVE

To explore the early childhood pulmonary outcomes of infants who participated in the National Institute of Child Health and Human Development's Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial (SUPPORT), using a factorial design that randomized extremely preterm infants to lower vs higher oxygen saturation targets and delivery room continuous positive airway pressure (CPAP) vs intubation/surfactant.

STUDY DESIGN

The Breathing Outcomes Study, a prospective secondary study to the Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial, assessed respiratory morbidity at 6-month intervals from hospital discharge to 18-22 months corrected age (CA). Two prespecified primary outcomes-wheezing more than twice per week during the worst 2-week period and cough longer than 3 days without a cold-were compared for each randomized intervention.

RESULTS

One or more interviews were completed for 918 of the 922 eligible infants. The incidences of wheezing and cough were 47.9% and 31.0%, respectively, and did not differ between the study arms of either randomized intervention. Infants randomized to lower vs higher oxygen saturation targets had a similar risk of death or respiratory morbidity (except for croup and treatment with oxygen or diuretics at home). Infants randomized to CPAP vs intubation/surfactant had fewer episodes of wheezing without a cold (28.9% vs 36.5%; P<.05), respiratory illnesses diagnosed by a doctor (47.7% vs 55.2%; P<.05), and physician or emergency room visits for breathing problems (68.0% vs 72.9%; P<.05) by 18-22 months CA.

CONCLUSION

Treatment with early CPAP rather than intubation/surfactant is associated with less respiratory morbidity by 18-22 months CA. Longitudinal assessment of pulmonary morbidity is necessary to fully evaluate the potential benefits of respiratory interventions for neonates.

Death or neurodevelopmental impairment at 18 to 22 months corrected age in a randomized trial of early dexamethasone to prevent death or chronic lung disease in extremely low birth weight infants

OBJECTIVE

To evaluate the incidence of death or neurodevelopmental impairment (NDI) at 18-22 months corrected age in subjects enrolled in a trial of early dexamethasone treatment to prevent death or chronic lung disease in extremely low birth weight infants.

STUDY DESIGN

Evaluation of infants at 18-22 months corrected age included anthropomorphic measurements, a standard neurological examination, and the Bayley Scales of Infant Development-II, including the Mental Developmental Index and the Psychomotor Developmental Index. NDI was defined as moderate or severe cerebral palsy, Mental Developmental Index or Psychomotor Developmental Index <70, blindness, or hearing impairment.

RESULTS

Death or NDI at 18-22 months corrected age was similar in the dexamethasone and placebo groups (65% vs 66%, P = .99 among those with known outcome). The proportion of survivors with NDI was also similar, as were mean values for weight, length, and head circumference and the proportion of infants with poor growth (50% vs 41%, P = .42 for weight less than 10th percentile); 49% of infants in the placebo group received treatment with corticosteroid compared with 32% in the dexamethasone group (P = .02).

CONCLUSION

The risk of death or NDI and rate of poor growth were high but similar in the dexamethasone and placebo groups. The lack of a discernible effect of early dexamethasone on neurodevelopmental outcome may be due to frequent clinical corticosteroid use in the placebo group.

Neurodevelopmental outcome of extremely low birth weight infants with Candida infection

OBJECTIVE

Candida remains an important cause of late-onset infection in preterm infants. Mortality and neurodevelopmental outcome of extremely low birth weight (ELBW) infants enrolled in the Candida study were evaluated based on infection status.

STUDY DESIGN

ELBW infants born at Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) centers between March 2004 and July 2007 who were 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 of the 1515 infants (87%) enrolled in the Candida study. The Bayley Scales of Infant Development-II or -III was administered at 18 months' adjusted age. A secondary comparison was performed with 864 infants enrolled in the NRN Generic Database during the same cohort who were never screened for sepsis and therefore not eligible for the Candida study.

RESULTS

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, 95% CI 1.01-3.33, P = .047).

CONCLUSIONS

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.

Neurodevelopmental outcomes of extremely low-gestational-age neonates with low-grade periventricular-intraventricular hemorrhage

IMPORTANCE

Low-grade periventricular-intraventricular hemorrhage is a common neurologic morbidity among extremely low-gestational-age neonates, yet the outcomes associated with this morbidity are not fully understood. In a contemporary multicenter cohort, we evaluated the impact of such hemorrhages on early (18-22 month) neurodevelopmental outcomes of extremely premature infants.

OBJECTIVE

To compare neurodevelopmental outcomes at 18 to 22 months' corrected age for extremely low-gestational-age infants with low-grade (grade 1 or 2) periventricular-intraventricular hemorrhage with those of infants with either no hemorrhage or severe (grade 3 or 4) hemorrhage demonstrated on cranial ultrasonography.

DESIGN

Longitudinal observational study.

SETTING

Sixteen centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network.

PARTICIPANTS

A total of 1472 infants born at less than 27 weeks' gestational age between January 1, 2006, and December 31, 2008, with ultrasonography results within the first 28 days of life and surviving to 18 to 22 months with complete follow-up assessments were eligible.

MAIN EXPOSURE

Low-grade periventricular-intraventricular hemorrhage.

MAIN OUTCOME MEASURES

Outcomes included cerebral palsy; gross motor functional limitation; cognitive and language scores according to the Bayley Scales of Infant Development, 3rd Edition; and composite measures of neurodevelopmental impairment. Regression modeling evaluated the association of hemorrhage severity with adverse outcomes while controlling for potentially confounding variables and center differences.

RESULTS

Low-grade hemorrhage was not associated with significant differences in unadjusted or adjusted risk of any adverse neurodevelopmental outcome compared with infants without hemorrhage. Compared with low-grade hemorrhage, severe hemorrhage was associated with decreased adjusted continuous cognitive (β, -3.91 [95% CI, -6.41 to -1.42]) and language (β, -3.19 [-6.19 to -0.19]) scores as well as increased odds of each adjusted categorical outcome except severe cognitive impairment (odds ratio [OR], 1.46 [0.74 to 2.88]) and mild language impairment (OR, 1.35 [0.88 to 2.06]).

CONCLUSIONS AND RELEVANCE

At 18 to 22 months, the neurodevelopmental outcomes of extremely low-gestational-age infants with low-grade periventricular-intraventricular hemorrhage are not significantly different from those without hemorrhage. Additional study at school age and beyond would be informative.

Neurodevelopmental outcomes in the early CPAP and pulse oximetry trial

BACKGROUND

Previous results from our trial of early treatment with continuous positive airway pressure (CPAP) versus early surfactant treatment in infants showed no significant difference in the outcome of death or bronchopulmonary dysplasia. A lower (vs. higher) target range of oxygen saturation was associated with a lower rate of severe retinopathy but higher mortality. We now report longer-term results from our prespecified hypotheses.

METHODS

Using a 2-by-2 factorial design, we randomly assigned infants born between 24 weeks 0 days and 27 weeks 6 days of gestation to early CPAP with a limited ventilation strategy or early surfactant administration and to lower or higher target ranges of oxygen saturation (85 to 89% or 91 to 95%). The primary composite outcome for the longer-term analysis was death before assessment at 18 to 22 months or neurodevelopmental impairment at 18 to 22 months of corrected age.

RESULTS

The primary outcome was determined for 1234 of 1316 enrolled infants (93.8%); 990 of the 1058 surviving infants (93.6%) were evaluated at 18 to 22 months of corrected age. Death or neurodevelopmental impairment occurred in 27.9% of the infants in the CPAP group (173 of 621 infants), versus 29.9% of those in the surfactant group (183 of 613) (relative risk, 0.93; 95% confidence interval [CI], 0.78 to 1.10; P=0.38), and in 30.2% of the infants in the lower-oxygen-saturation group (185 of 612), versus 27.5% of those in the higher-oxygen-saturation group (171 of 622) (relative risk, 1.12; 95% CI, 0.94 to 1.32; P=0.21). Mortality was increased with the lower-oxygen-saturation target (22.1%, vs. 18.2% with the higher-oxygen-saturation target; relative risk, 1.25; 95% CI, 1.00 to 1.55; P=0.046).

CONCLUSIONS

We found no significant differences in the composite outcome of death or neurodevelopmental impairment among extremely premature infants randomly assigned to early CPAP or early surfactant administration and to a lower or higher target range of oxygen saturation. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Heart, Lung, and Blood Institute; SUPPORT ClinicalTrials.gov number, NCT00233324.).

Are outcomes of extremely preterm infants improving? Impact of Bayley assessment on outcomes

OBJECTIVES

To compare 18- to 22-month cognitive scores and neurodevelopmental impairment (NDI) in 2 time periods using the National Institute of Child Health and Human Development's Neonatal Research Network assessment of extremely low birth weight infants with the Bayley Scales of Infant Development, Second Edition (Bayley II) in 2006-2007 (period 1) and using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley III), with separate cognitive and language scores, in 2008-2011 (period 2).

STUDY DESIGN

Scores were compared with bivariate analysis, and regression analyses were run to identify differences in NDI rates.

RESULTS

Mean Bayley III cognitive scores were 11 points higher than mean Bayley II cognitive scores. The NDI rate was reduced by 70% (from 43% in period 1 to 13% in period 2; P < .0001). Multivariate analyses revealed that Bayley III contributed to a decreased risk of NDI by 5 definitions: cognitive score <70 and <85, cognitive or language score <70; cognitive or motor score <70, and cognitive, language, or motor score <70 (P < .001).

CONCLUSION

Whether the Bayley III is overestimating cognitive performance or whether it is a more valid assessment of emerging cognitive skills than the Bayley II is uncertain. Because the Bayley III identifies significantly fewer children with disability, it is recommended that all extremely low birth weight infants be offered early intervention services at the time of discharge from the neonatal intensive care unit, and that Bayley scores be interpreted with caution.

Childhood outcomes after hypothermia for neonatal encephalopathy

BACKGROUND

We previously reported early results of a randomized trial of whole-body hypothermia for neonatal hypoxic-ischemic encephalopathy showing a significant reduction in the rate of death or moderate or severe disability at 18 to 22 months of age. Long-term outcomes are now available.

METHODS

In the original trial, we assigned infants with moderate or severe encephalopathy to usual care (the control group) or whole-body cooling to an esophageal temperature of 33.5°C for 72 hours, followed by slow rewarming (the hypothermia group). We evaluated cognitive, attention and executive, and visuospatial function; neurologic outcomes; and physical and psychosocial health among participants at 6 to 7 years of age. The primary outcome of the present analyses was death or an IQ score below 70.

RESULTS

Of the 208 trial participants, primary outcome data were available for 190. Of the 97 children in the hypothermia group and the 93 children in the control group, death or an IQ score below 70 occurred in 46 (47%) and 58 (62%), respectively (P=0.06); death occurred in 27 (28%) and 41 (44%) (P=0.04); and death or severe disability occurred in 38 (41%) and 53 (60%) (P=0.03). Other outcome data were available for the 122 surviving children, 70 in the hypothermia group and 52 in the control group. Moderate or severe disability occurred in 24 of 69 children (35%) and 19 of 50 children (38%), respectively (P=0.87). Attention-executive dysfunction occurred in 4% and 13%, respectively, of children receiving hypothermia and those receiving usual care (P=0.19), and visuospatial dysfunction occurred in 4% and 3% (P=0.80).

CONCLUSIONS

The rate of the combined end point of death or an IQ score of less than 70 at 6 to 7 years of age was lower among children undergoing whole-body hypothermia than among those undergoing usual care, but the differences were not significant. However, hypothermia resulted in lower death rates and did not increase rates of severe disability among survivors. (Funded by the National Institutes of Health and the Eunice Kennedy Shriver NICHD Neonatal Research Network; ClinicalTrials.gov number, NCT00005772.).

Prediction of bronchopulmonary dysplasia by postnatal age in extremely premature infants

RATIONALE

Benefits of identifying risk factors for bronchopulmonary dysplasia in extremely premature infants include providing prognostic information, identifying infants likely to benefit from preventive strategies, and stratifying infants for clinical trial enrollment.

OBJECTIVES

To identify risk factors for bronchopulmonary dysplasia, and the competing outcome of death, by postnatal day; to identify which risk factors improve prediction; and to develop a Web-based estimator using readily available clinical information to predict risk of bronchopulmonary dysplasia or death.

METHODS

We assessed infants of 23-30 weeks' gestation born in 17 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network and enrolled in the Neonatal Research Network Benchmarking Trial from 2000-2004.

MEASUREMENTS AND MAIN RESULTS

Bronchopulmonary dysplasia was defined as a categorical variable (none, mild, moderate, or severe). We developed and validated models for bronchopulmonary dysplasia risk at six postnatal ages using gestational age, birth weight, race and ethnicity, sex, respiratory support, and Fi(O(2)), and examined the models using a C statistic (area under the curve). A total of 3,636 infants were eligible for this study. Prediction improved with advancing postnatal age, increasing from a C statistic of 0.793 on Day 1 to a maximum of 0.854 on Day 28. On Postnatal Days 1 and 3, gestational age best improved outcome prediction; on Postnatal Days 7, 14, 21, and 28, type of respiratory support did so. A Web-based model providing predicted estimates for bronchopulmonary dysplasia by postnatal day is available at https://neonatal.rti.org.

CONCLUSIONS

The probability of bronchopulmonary dysplasia in extremely premature infants can be determined accurately using a limited amount of readily available clinical information.

Early-childhood neurodevelopmental outcomes are not improving for infants born at <25 weeks' gestational age

OBJECTIVE

We compared neurodevelopmental outcomes at 18 to 22 months' corrected age of infants born with extremely low birth weight at an estimated gestational age of <25 weeks during 2 periods: 1999-2001 (epoch 1) and 2002-2004 (epoch 2).

PATIENTS AND METHODS

We conducted a multicenter, retrospective analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Perinatal and neonatal variables and outcomes were compared between epochs. Neurodevelopmental outcomes at 18 to 22 months' corrected age were evaluated with neurologic exams and Bayley Scales of Infant Development II. Logistic regression analyses determined the independent risk of epoch for adverse outcomes.

RESULTS

Infant survival was similar between epochs (epoch 1, 35.4%, vs epoch 2, 32.3%; P = .09). A total of 411 of 452 surviving infants in epoch 1 and 405 of 438 surviving infants in epoch 2 were evaluated at 18 to 22 months' corrected age. Cesarean delivery (P = .03), surgery for patent ductus arteriosus (P = .004), and late sepsis (P = .01) were more common in epoch 2, but postnatal steroid use was dramatically reduced (63.5% vs 32.8%; P < .0001). Adverse outcomes at 18 to 22 months' corrected age were common in both epochs. Moderate-to-severe cerebral palsy was diagnosed in 11.1% of surviving infants in epoch 1 and 14.9% in epoch 2 (adjusted odds ratio [OR]: 1.52 [95% confidence interval (CI): 0.86-2.71]; P = .15), the Mental Developmental Index was <70 in 44.9% in epoch 1 and 51% in epoch 2 (OR: 1.30 [95% CI: 0.91-1.87]; P = .15), and neurodevelopmental impairment was diagnosed in 50.1% of surviving infants in epoch 1 and 58.7% in epoch 2 (OR: 1.4 [95% CI: 0.98-2.04]; P = .07).

CONCLUSIONS

Early-childhood outcomes for infants born at <25 weeks' estimated gestational age were unchanged between the 2 periods.

Treated hypotension is associated with neonatal morbidity and hearing loss in extremely low birth weight infants

BACKGROUND

Neonatal hypotension may be a risk factor for neurologic impairment. Few studies have examined the impact of low blood pressure in extremely low birth weight (ELBW) infants weighing 400 to 999 g on neurodevelopmental outcome.

OBJECTIVES

We set out to explore the relationship between treated hypotension in the first 72 hours of life and perinatal factors, morbidity, and mortality in ELBW infants and then to compare neurosensory outcome in ELBW infants with treated hypotension and those who never received treatment for hypotension.

DESIGN/METHODS

We performed chart review of all 156 ELBW infants admitted to our level III NICU in 1998-1999. Infants had "treated hypotension" if they received fluid pushes, corticosteroids, and/or vasopressors during the first 72 hours of life in an attempt to increase blood pressure. Follow-up included neurologic examination, Bayley Scales of Infant Development, vision and hearing evaluation. Statistical analysis was performed by using SPSS 11.0. Univariate and multivariate analyses were conducted to determine morbidities associated with treated hypotension.

RESULTS

Fifty-nine infants received treatment for hypotension. Ninety-seven infants did not. The groups had similar race, gender, delivery mode, chorioamnionitis, and maternal socioeconomic status. Thirty-eight (24%) infants expired, including 20 who received treatment for hypotension. Of the 156 infants in the study group, 110 underwent neurodevelopment testing, and 103 were able to undergo complete neurodevelopment testing and Bayley examination. Multivariate analysis controlling for socioeconomic status and neonatal morbidity revealed that treated hypotension is associated with delayed motor development and hearing loss.

CONCLUSIONS

Treated hypotension in ELBW infants in the first 72 hours of life is associated with significant short-term and long-term morbidity. Infants with treated hypotension are more likely to have delayed motor development, hearing loss, and death.

Center differences and outcomes of extremely low birth weight infants

OBJECTIVE

Previous multicenter studies have shown significant center differences in neonatal characteristics and morbidities. This study evaluated center differences in outcome at 18 to 22 months among extremely low birth weight (ELBW; 401-1000 g) infants after adjusting for demographics and antenatal interventions, and it identified neonatal interventions associated with outcome differences.

METHODS

We assessed the outcome of 2478 liveborn infants who were admitted in 1993 and 1994 to the 12 centers of the Neonatal Research Network of the National Institute of Child Health and Human Development; 1483 (60%) infants survived to 18 to 22 months, and 1151 (78%) had comprehensive evaluations. Logistic regression analyses were performed to identify center differences and the association of 4 neonatal interventions--active resuscitation, postnatal steroids, ventilator treatment for < or =27 days, and full enteral feedings < or =24 days--with adverse outcomes (cerebral palsy, low Bayley scores, and neurodevelopmental impairment [NDI]), after adjusting for demographics and antenatal interventions.

RESULTS

Using bivariate analyses, significant center differences were identified for mortality, antenatal and postnatal interventions, social and environmental variables, neonatal morbidities, and neurodevelopmental outcomes for the 12 centers. After adjustment for maternal and infant demographics and antenatal interventions, the percentage of ELBW infants who had died or had NDI at 18 to 22 months ranged from 52% to 85%. Active resuscitation and postnatal steroids were associated with increases of NDI of 11.8% and 19.3%, whereas shorter ventilation support and shorter time to achieve full enteral feeds were associated with decreases in NDI of 20.7% and 17.3%, respectively.

CONCLUSION

There are large and disturbing differences among centers in outcomes at 18 to 22 months after adjusting for demographic and antenatal interventions. Center differences in postnatal interventions associated with differences in outcome can provide hypotheses for testing in clinical trials to improve outcome.