Network on care of and morbidity and mortality rates for very low birth weight infants, according to gestational age (GA).METHODS-Perinatal/neonatal data were collected for 9575 infants of extremely low GA (22-28 weeks) and very low birth weight (401-1500 g) who were born at network centers between January 1, 2003, and December 31, 2007. RESULTS-Rates of survival to discharge increased with increasing GA (6% at 22 weeks and 92% at 28 weeks); 1060 infants died at ≤ 12 hours, with most early deaths occurring at 22 and 23 weeks (85% and 43%, respectively). Rates of prenatal steroid use (13% and 53%, respectively), cesarean section (7% and 24%, respectively), and delivery room intubation (19% and 68%, respectively) increased markedly between 22 and 23 weeks. Infants at the lowest GAs were at greatest risk for morbidities. Overall, 93% had respiratory distress syndrome, 46% patent ductus arteriosus, 16% severe intraventricular hemorrhage, 11% necrotizing enterocolitis, and 36% late-onset sepsis. The new severity-based definition of bronchopulmonary dysplasia classified more infants as having bronchopulmonary dysplasia than did the traditional definition of supplemental oxygen use at 36 weeks (68%, compared with 42%). More than one-half of infants with extremely low GAs had undetermined retinopathy status at the time of discharge. Center differences in management and outcomes were identified.CONCLUSION-Although the majority of infants with GAs of ≥24 weeks survive, high rates of morbidity among survivors continue to be observed. Keywordsextremely low gestation; very low birth weight; morbidity; death Over the previous 2 decades, the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) has monitored trends in morbidity and mortality rates among very low birth weight (VLBW) infants born at the university centers that constitute the NRN. 1-6 Increased VLBW infant survival rates have paralleled improvements in prenatal, obstetric, and neonatal care.7 , 8 NRN data suggest that a plateau in VLBW infant survival rates might have been reached, despite increased use of prenatal corticosteroid treatment, prenatal antibiotic treatment, and early neonatal surfactant treatment. 6 Previous NRN reports presented patient characteristics, interventions, and outcomes according to birth weight (BW), with an upper limit of 1500 g. Such BW-specific data may be skewed by more-mature infants with growth restriction. The aim of this study was to evaluate management, hospital complications, and mortality rates among infants with gestational ages (GAs) of 22 to 28 weeks who were born at NRN centers between 2003 and 2007. METHODS Study Population and Clinical OutcomesInfants born alive at NRN centers in 2003-2007 with GAs of 22 0/7 to 28 6/7 weeks and BWs of 401 to 1500 g were studied, including those with congenital anomalies. These infants were part of the NRN VLBW registry. [1][2][3][4][5][6] Research personnel collected maternal pregnancy/delivery data soon after birth and inf...

Importance Extremely preterm infants contribute disproportionately to neonatal morbidity and mortality. Objective To review 20-year trends in maternal/neonatal care, complications, and mortality among extremely preterm infants born at Neonatal Research Network centers. Design, Setting, Participants Prospective registry of 34,636 infants 22–28 weeks’ gestational age (GA) and 401–1500 gram birthweight born at 26 Network centers, 1993–2012. Exposure Extremely preterm birth. Main Outcomes Maternal/neonatal care, morbidities, and survival. Major morbidities, reported for infants who survived more than 12 hours, were: severe necrotizing enterocolitis, infection, bronchopulmonary dysplasia, severe intracranial hemorrhage, cystic periventricular leukomalacia, and/or severe retinopathy of prematurity. Regression models assessed yearly changes, adjusting for study center, race/ethnicity, GA, birthweight for GA, and sex. Results Use of antenatal corticosteroids increased from 1993 to 2012 (348/1431 [24%] to 1674/1919 [87%], p<0.001), as did cesarean delivery (625/1431 [44%] to 1227/1921 [64%], p<0.001). Delivery room intubation decreased from 1144/1433 (80%) in 1993 to 1253/1922 (65%) in 2012 (p<0.001). After increasing in the 1990s, postnatal steroid use declined to 141/1757 (8%) in 2004 (p<0.001), with no significant change thereafter. Although most infants were ventilated, continuous positive airway pressure without ventilation increased from 120/1666 (7%) in 2002 to 190/1756 (11%) in 2012 (p<0.001). Despite no improvement from 1993 to 2004, rates of late-onset sepsis declined between 2005 and 2012 for infants of each GA (median GA 26 weeks, 109/296 [37%] to 85/320 [27%], adjusted relative risk [aRR]: 0.93 [95% CI, 0.92–0.94]). Rates of other morbidities declined, but bronchopulmonary dysplasia increased between 2009 and 2012 for infants 26–27 weeks (26 weeks, 130/258 [50%] to 164/297 [55%], p<0.001). Survival increased between 2009 and 2012 for infants 23 weeks (41/152 [27%] to 50/150 [33%], aRR: 1.09 [95% CI, 1.05–1.14]) and 24 weeks (156/248 [63%] to 174/269 [65%], aRR: 1.05 [95% CI, 1.03–1.07]), with smaller relative increases for infants 25 and 27 weeks and no change for infants 22, 26 and 28 weeks. Survival without major morbidity increased approximately 2% per year for infants 25–28 weeks with no change for infants 22–24 weeks. Conclusions and Relevance Among extremely preterm infants born at US academic centers over the last 20 years, changes in maternal and infant care practices and modest reductions in several morbidities were observed, although bronchopulmonary dysplasia increased. Survival increased most markedly for infants born at 23 and 24 weeks and survival without major morbidity increased for infants 25–28 weeks. These findings may be valuable in counselling families and developing novel interventions.

The physiologic definition of BPD reduced the overall rate of BPD and reduced the variation among centers. Significant center differences in the impact of the physiologic definition were seen, and differences remained even with the use of this standardized definition. The magnitude of the change in BPD rate is comparable to the magnitude of treatment effects seen in some clinical trials in BPD. The physiologic definition of BPD facilitates the measurement of BPD as an outcome in clinical trials and the comparison between and within centers over time.

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. 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.Keywords: bronchopulmonary dysplasia; prematurity; low-birth-weight infant AT A GLANCE COMMENTARY Scientific Knowledge on the SubjectBronchopulmonary dysplasia is the most common serious pulmonary morbidity in premature infants. Although accurate predictive models of bronchopulmonary dysplasia risk are sometimes used in research, none are currently used in common clinical practice for a variety of reasons. What This Study Adds to the FieldIn this study, we identified the change in the relative contributions of a variety of risk factors to the prediction of bronchopulmonary dysplasia with advancing postnatal age. This tool may help identify patients most likely to benefit from postnatal treatment and assist in the design of clinical trials to assess the efficacy of preventive therapies in high-risk populations.