Neonatal Outcomes of Very Low Birth Weight and Very Preterm Neonates: An International Comparison

Indications and outcomes of paediatric tracheotomy: a descriptive study using a Japanese claims database

OBJECTIVE

To examine the incidence of and indications for paediatric tracheotomy to clarify the disease burden relevant to tracheotomy in a population-based context.

DESIGN

A descriptive analysis of a retrospective cohort.

SETTING

This study utilised a nationwide claims database in Japan constructed by JMDC (Tokyo, Japan). The database includes claims data for approximately 3.75 million insured persons (approximately 3.1% of the population of Japan) comprising mainly company employees and their family members.

PARTICIPANTS

We identified children registered to have undergone tracheotomy from 2005 to 2017 among about 1.2 million children aged 0-15 years.

MAIN OUTCOME MEASURES

The characteristics of the study population, and indications for tracheotomy, duration of hospital stay, duration of mechanical ventilation, duration of tracheotomy dependence, complications related to tracheotomy and death were assessed. When there were multiple indications, classification for a child into multiple groups was allowed.

RESULTS

The study included 215 children (120 males, 56%). The median age at tracheotomy was 0.8 years. The most common age at tracheotomy was less than 12 months (n=127, 59.1%). The most common indications for tracheotomy were chronic lung disease (n=79, 36.7%), followed by neuromuscular disease (n=77, 35.8%), cardiovascular disease (n=53, 24.3%), upper airway obstruction (n=43, 20%), premature birth and related conditions (n=34, 15.8%), trauma (n=16, 7.4%), prolonged ventilation due to other causes (n=12, 5.6%) and malignancy (n=9, 4.2%). The median duration of tracheotomy dependence was 17.2 months. During the follow-up period, decannulation was achieved in 84 children (39.1%), and the median time from tracheotomy to decannulation was 12.0 months.

CONCLUSIONS

Most paediatric tracheotomies were performed due to chronic underlying diseases, and the mean duration of tracheotomy dependence was nearly 1-½ years. The long-term duration of tracheotomy dependence might have some impacts on patients' physical and mental development and the quality of life.

Trends in Outcomes for Neonates Born Very Preterm and Very Low Birth Weight in 11 High-Income Countries

OBJECTIVE

To evaluate outcome trends of neonates born very preterm in 11 high-income countries participating in the International Network for Evaluating Outcomes of neonates.

STUDY DESIGN

In a retrospective cohort study, we included 154 233 neonates admitted to 529 neonatal units between January 1, 2007, and December 31, 2015, at 24^0/7 to 31^6/7 weeks of gestational age and birth weight <1500 g. Composite outcomes were in-hospital mortality or any of severe neurologic injury, treated retinopathy of prematurity, and bronchopulmonary dysplasia (BPD); and same composite outcome excluding BPD. Secondary outcomes were mortality and individual morbidities. For each country, annual outcome trends and adjusted relative risks comparing epoch 2 (2012-2015) to epoch 1 (2007-2011) were analyzed.

RESULTS

For composite outcome including BPD, the trend decreased in Canada and Israel but increased in Australia and New Zealand, Japan, Spain, Sweden, and the United Kingdom. For composite outcome excluding BPD, the trend decreased in all countries except Spain, Sweden, Tuscany, and the United Kingdom. The risk of composite outcome was lower in epoch 2 than epoch 1 in Canada (adjusted relative risks 0.78; 95% CI 0.74-0.82) only. The risk of composite outcome excluding BPD was significantly lower in epoch 2 compared with epoch 1 in Australia and New Zealand, Canada, Finland, Japan, and Switzerland. Mortality rates reduced in most countries in epoch 2. BPD rates increased significantly in all countries except Canada, Israel, Finland, and Tuscany.

CONCLUSIONS

In most countries, mortality decreased whereas BPD increased for neonates born very preterm.

Bronchopulmonary dysplasia

In the absence of effective interventions to prevent preterm births, improved survival of infants who are born at the biological limits of viability has relied on advances in perinatal care over the past 50 years. Except for extremely preterm infants with suboptimal perinatal care or major antenatal events that cause severe respiratory failure at birth, most extremely preterm infants now survive, but they often develop chronic lung dysfunction termed bronchopulmonary dysplasia (BPD; also known as chronic lung disease). Despite major efforts to minimize injurious but often life-saving postnatal interventions (such as oxygen, mechanical ventilation and corticosteroids), BPD remains the most frequent complication of extreme preterm birth. BPD is now recognized as the result of an aberrant reparative response to both antenatal injury and repetitive postnatal injury to the developing lungs. Consequently, lung development is markedly impaired, which leads to persistent airway and pulmonary vascular disease that can affect adult lung function. Greater insights into the pathobiology of BPD will provide a better understanding of disease mechanisms and lung repair and regeneration, which will enable the discovery of novel therapeutic targets. In parallel, clinical and translational studies that improve the classification of disease phenotypes and enable early identification of at-risk preterm infants should improve trial design and individualized care to enhance outcomes in preterm infants.

Screening and novel therapies for retinopathy of prematurity - A review

With current screening for sight threatening retinopathy of prematurity (ROP) <10% of screened infants need treatment. Prediction models based on birth characteristics, postnatal weight gain and other factors have been developed to reduce examinations in low-risk infants. A model based on advanced statistics using data from >7000 infants registered in the Swedish ROP registry is being developed. Based on birth characteristics only, it appears to predict total risk of ROP-treatment as well as models including weight measurements. Treatment risk peaked at 12 weeks of age. Laser therapy is the method of choice for severe ROP. Anti-VEGF therapies are implemented worldwide despite insufficient knowledge of choice of drug, dosage and long term systemic effects. Prevention of ROP may be achieved through oxygen control and provision of the mother's breastmilk. Other interventions such as supplementation with long chain polyunsaturated fatty acids and preservation of fetal haemoglobin are investigated.

Establishing a neonatal database in a tertiary hospital in Rwanda - an observational study

Background: Monitoring and evaluation is vital in the quest to improve the quality of care and to reduce the morbidity and mortality of neonates in a resource-limited setting. Databases offer several advantages such as data on large cohorts of neonates and from multiple centres. Aim: To establish a minimal dataset neonatal database in Kigali, Rwanda and to assess the quality and timing of the data entry process. Secondary objectives were to describe survival rates and associated risk factors. Methods: A cross-sectional, observational study was undertaken at a tertiary hospital in Kigali, Rwanda. The Rwanda Neonatal Data Collection Form was designed specifically for the database, based on the Vermont-Oxford Network neonatal data-collection tool with locally relevant amendments. All admitted neonates were enrolled during the study period of 2011-2017 with ongoing data-collection. Infants were recruited and data collected prospectively and cross-checked retrospectively with the inclusion of basic data on neonates who were not initially recruited prospectively. Results: 3391 analysable cases were recruited: 1420 prospective and 1971 retrospective cases. Prospective data collection peaked at 90%. Data entry was not always complete with data-points left blank with only 21% having adequate data available (0-25% missing). All-cause mortality during the study period was 16% and annual mortality ranged from 12% to 24%. On multivariate analysis, place of birth (AOR 2.17), small-for-gestational-age (AOR 2.05) and gestational age were all positively associated with survival. Conclusions: An academic setting in a low- or middle-income country can create and maintain a neonatal database without funding and produce a wealth of actionable results. Throughout the process, there were considerable challenges which must be addressed if such a database is to be optimised, maintained and created in other clinical sites. Abbreviations: CHUK: Centre Hospitalier et Universitaire de Kigali (University Teaching Hospital of Kigali); CPAP: continuous positive airway pressure; HCP: Healthcare professional; HRH, Human Resources for Health Programme; LMIC: low- and middle-income countries; MeSH: Medical subject headings; MoH: Ministry of Health; NAR: Newborn admission record; QI: Quality improvement; REDCap: Research electronic data capture; RNDB: Rwanda neonatal database; RNDCF: Rwanda neonatal data collecion form; SGA: Small for gestational age; STROBE: Strengthening the reporting of observational studies in epidemiology; VON: The Vermont-Oxford Network.

Intraventricular Hemorrhage: Risk Factors and Association With Patent Ductus Arteriosus Treatment in Extremely Preterm Neonates

Objectives: To assess maternal and neonatal risk factors for intraventricular hemorrhage (IVH). To examine the association of patent ductus arteriosus (PDA) and its treatment, with IVH and its severity. Study design: In this retrospective cohort study, we included preterm neonates born at <29 weeks, admitted to a tertiary level III Neonatal Intensive Care Unit in Calgary, Canada, between 2013 and 2016, who had a head ultrasound in the first 7 days of life. A subset analysis included neonates who also had cardiac ultrasound in the first 3 days of life. Results: Of the 495 neonates, 121 (24.4%) had IVH of any grade and 48 (9.7%) had severe IVH. Identified risk factors were small birth gestation and weight, lack of antenatal corticosteroids, maternal chorioamnionitis, Apgar score <5 at 5 min, umbilical cord pH < 7, respiratory distress syndrome, early onset sepsis, hypercapnia, pCO2 fluctuations, prolonged intubation, inhaled nitric oxide, inotropes or normal saline boluses, metabolic derangements, opioids infusions, and bicarbonate/THAM therapy. In a primary analysis of the total cohort, when the decision to treat a PDA was used as a surrogate marker of its clinical significance, a PDA requiring treatment was associated with a higher risk of IVH. There was no significant difference in the incidence of IVH between neonates with early treatment of a clinically significant PDA compared to late, however early indomethacin treatment was associated with reduced severity of IVH. In the subset analysis, the presence of a hemodynamically significant PDA (hs-PDA) was not associated with a higher probability of IVH. Of those with severe IVH, 18 (55%) had a hs-PDA; this is clinically but not statistically significant. Conclusions: Identified risk factors should be the target of IVH reduction bundles. Early indomethacin treatment for a clinically significant PDA may reduce IVH severity.

Preventive strategies and factors associated with surgically treated necrotising enterocolitis in extremely preterm infants: an international unit survey linked with retrospective cohort data analysis

OBJECTIVES

To compare necrotising enterocolitis (NEC) prevention practices and NEC associated factors between units from eight countries of the International Network for Evaluation of Outcomes of Neonates, and to assess their association with surgical NEC rates.

DESIGN

Prospective unit-level survey combined with retrospective cohort study.

SETTING

Neonatal intensive care units in Australia/New Zealand, Canada, Finland, Israel, Spain, Sweden, Switzerland and Tuscany (Italy).

PATIENTS

Extremely preterm infants born between 24⁰ to 28⁶ weeks' gestation, with birth weights<1500 g, and admitted between 2014-2015.

EXPOSURES

NEC prevention practices (probiotics, feeding, donor milk) using responses of an on-line pre-piloted questionnaire containing 10 questions and factors associated with NEC in literature (antenatal steroids, c-section, indomethacin treated patent ductus arteriosus and sepsis) using cohort data.

OUTCOME MEASURES

Surgical NEC rates and death following NEC using cohort data.

RESULTS

The survey response rate was 91% (153 units). Both probiotic provision and donor milk availability varied between 0%-100% among networks whereas feeding initiation and advancement rates were similar in most networks. The 9792 infants included in the cohort study to link survey results and cohort outcomes, revealed similar baseline characteristics but considerable differences in factors associated with NEC between networks. 397 (4.1%) neonates underwent NEC surgery, ranging from 2.4%-8.4% between networks. Standardised ratios for surgical NEC were lower for Australia/New Zealand, higher for Spain, and comparable for the remaining six networks.

CONCLUSIONS

The variation in implementation of NEC prevention practices and in factors associated with NEC in literature could not be associated with the variation in surgical NEC incidence. This corroborates the current lack of consensus surrounding the use of preventive strategies for NEC and emphasises the need for research.

Short- and Long-Term Outcomes of Extremely Preterm Infants in Japan According to Outborn/Inborn Birth Status

OBJECTIVES

Outborn (born outside tertiary centers) infants, especially extremely preterm infants, are at an increased risk of mortality and morbidity in comparison to inborn (born in tertiary centers) infants. Extremely preterm infants require not only skilled neonatal healthcare providers but also highly specialized equipment and environment surroundings. Maternal transport at an appropriate timing must be done to avoid the delivery of extremely preterm infants in a facility without the necessary capabilities. Cases of unexpected deliveries at birth centers or level I maternity hospitals need to be attended emergently. We compared the differences in short- and long-term outcomes between outborn and inborn infants to improve our regional perinatal system.

DESIGN

Retrospective cohort study.

SETTING

Neonatal Research Network of Japan database.

PATIENTS

Extremely preterm infants (gestational age between 22 + 0 and 27 + 6 wk) in the Neonatal Research Network of Japan database between 2003 and 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 12,164 extremely preterm infants, who were divided into outborn (n = 785, 6.5%) and inborn (n = 11,379, 93.5%) groups, were analyzed. Significant differences were observed in demographic and clinical factors between the two groups. Outborn infants had higher short-term odds of severe intraventricular hemorrhage (adjusted odds ratio, 1.49; 95% CI, 1.11-2.00; p < 0.01), necrotizing enterocolitis (adjusted odds ratio, 1.49; 95% CI, 1.11-2.00; p < 0.01), and focal intestinal perforation (adjusted odds ratio, 1.58; 95% CI, 1.09-2.30; p = 0.02). There were no significant differences in long-term outcomes between the two groups, except in the rate of cognitive impairment (adjusted odds ratio, 1.49; 95% CI, 1.01-2.20; p = 0.04).

CONCLUSIONS

The frequency of severe intraventricular hemorrhage, necrotizing enterocolitis or focal intestinal perforation, and cognitive impairment was significantly higher in outborn infants. Thus, outborn/inborn birth status may play a role in short- and long-term outcomes of extremely preterm infants. However, more data and evaluation of improvement in the current perinatal environment are needed.

Low mortality and short-term morbidity in very preterm infants in Austria 2011-2016

AIM

The current study determined survival, short-term neonatal morbidity and predictors for death or adverse outcome of very preterm infants in Austria.

METHODS

This population-based cohort study included 5197 very preterm infants (53.3% boys) born between 2011 and 2016 recruited from the Austrian Preterm Outcome Registry. Main outcome measures were gestational age-related mortality and major short-term morbidities.

RESULTS

Overall, survival rate of all live-born infants included was 91.6% and ranged from 47.1% and 73.4% among those born at 23 and 24 weeks of gestation to 84.9% and 88.2% among infants born at 25 and 26 weeks to more than 90.0% among those with a gestational age of 27 weeks or more. The overall prevalence of chronic lung disease, necrotising enterocolitis requiring surgery, intraventricular haemorrhage Grades 3-4, and retinopathy of prematurity Grades 3-5 was 10.0%, 2.1%, 5.5%, and 3.6%, respectively. Low gestational age, low birth weight, missing or incomplete course of antenatal steroids, male sex, and multiple births were significant risk predictors for death or adverse short-term outcome.

CONCLUSION

In this national cohort study, overall survival rates were high and short-term morbidity rate was low.

The clinical management and outcomes of extremely preterm infants in Japan: past, present, and future

There is a wide variation in neonatal mortality rates across regions and countries. Japan has one of the lowest neonatal mortality rates in the world; in particular, the mortality rate of extremely preterm infants (i.e., those born before 26 weeks of gestation) is much lower in Japan than in other developed countries. In addition, Japan has low incidences of intraventricular hemorrhage, necrotizing enterocolitis, and late-onset sepsis, a very high incidence of retinopathy of prematurity, and a relatively high incidence of chronic lung disease. In Japan, general perinatal medical centers (PMCs), which are PMCs that offer the highest levels of care, are required to have an obstetric department with maternal-fetal intensive care units as well as a neonatal or pediatric department with neonatal intensive care units (NICU), in order to promote antenatal rather than neonatal maternal transfer of high-risk cases. The limit of viability of extremely preterm infants is 22 weeks of gestation, and approximately half of them are estimated to receive active resuscitation. The clinical management of extremely preterm infants in Japan are characterized by (I) circulatory management that is guided by neonatologist-performed echocardiography, (II) relatively invasive respiratory management, (III) nutritional management, which entails the promotion of breast milk feeding, early enteral feeding, routine glycerin enema, and the administration of probiotics, (IV) neurological management by means of minimal handling, sedation of ventilated infants, and serial brain ultrasounds, and (V) infection control with the assistance of serial C-reactive protein (CRP) monitoring. Thus, this review provides a brief description of the development of neonatology in Japan, introduces the unique features of Japanese clinical management of extremely preterm infants, and overviews their outcomes.

Association of Center-Specific Patient Volumes and Early Respiratory Management Practices with Death and Bronchopulmonary Dysplasia in Preterm Infants

OBJECTIVES

To describe variability in admission volumes and approach to early respiratory support between neonatal intensive care units in the Australian and New Zealand Neonatal Network and to evaluate whether these center-specific factors are associated with death and bronchopulmonary dysplasia.

STUDY DESIGN

This retrospective cohort study included 19 099 neonates born between 25 and 32 weeks' gestation and admitted to 1 of 25 NICUs from 2007 to 2013. Center-specific factors evaluated were annual admission volume and rate of using continuous positive airway pressure (CPAP) rather than intubation as the first mode of respiratory support. Logistic regression was used to examine any association of these center-specific factors with death, BPD, and death or survival with BPD (death/BPD). Analysis was performed separately for 2 gestation groups (25-28 weeks and 29-32 weeks inclusive).

RESULTS

Admission volumes and rates of early CPAP use varied widely across centers. Higher admission volumes were associated with lower odds of death or survival with BPD in the 25-28 week group (aOR 0.93, 99% CI 0.88-0.99 per increase of 10 babies per center annually). Centers with higher early CPAP use did not have lower odds of death or BPD than centers that intubated more frequently.

CONCLUSIONS

Higher admission volumes are associated with more favorable outcomes for the more preterm infants in the Australian and New Zealand Neonatal Network. Further investigation is required to explore why the individual benefits of early CPAP do not translate to better outcomes for centers that use this approach most frequently.

The International Network for Evaluating Outcomes (iNeo) of neonates: evolution, progress and opportunities

Neonates born very preterm (before 32 weeks' gestational age), are a significant public health concern because of their high-risk of mortality and life-long disability. In addition, caring for very preterm neonates can be expensive, both during their initial hospitalization and their long-term cost of permanent impairments. To address these issues, national and regional neonatal networks around the world collect and analyse data from their constituents to identify trends in outcomes, and conduct benchmarking, audit and research. Improving neonatal outcomes and reducing health care costs is a global problem that can be addressed using collaborative approaches to assess practice variation between countries, conduct research and implement evidence-based practices. The International Network for Evaluating Outcomes (iNeo) of neonates was established in 2013 with the goal of improving outcomes for very preterm neonates through international collaboration and comparisons. To date, 10 national or regional population-based neonatal networks/datasets participate in iNeo collaboration. The initiative now includes data on >200,000 very preterm neonates and has conducted important epidemiological studies evaluating outcomes, variations and trends. The collaboration has also surveyed >320 neonatal units worldwide to learn about variations in practices, healthcare service delivery, and physical, environmental and manpower related factors and support services for parents. The iNeo collaboration serves as a strong international platform for Neonatal-Perinatal health services research that facilitates international data sharing, capacity building, and global efforts to improve very preterm neonate care.

Information technology infrastructure, quality improvement and research: the UK National Neonatal Research Database

Technological developments, coupled with strengthened governance and data security have led to increasing recognition of the potential of real-world health data to benefit patient care and health services. Real-world health data are those captured in the course of routine care. Here I describe a mature source of real-world health data, the UK National Neonatal Research Database and provide examples of the many types of uses it supports.

India to gear up to the challenge of "third epidemic" of retinopathy of prematurity in the world

Many of the causes of childhood blindness are avoidable, being either preventable or treatable. Retinopathy of prematurity (ROP) remains one of the most preventable causes of childhood blindness worldwide. Currently, India is facing the third epidemic of ROP. In India, the health system involving the mother and child health services needs to be strengthened with a policy to cover the existing inadequacies in neonatal care and implementation of program covering newborn, especially premature. The access, availability, and affordability of services related to the care of premature babies need strengthening in India. ROP-trained ophthalmologists and neonatal care pediatricians and a professional togetherness is a big issue. Inadequacies in awareness of ROP among the parents, health care workers, counsellors add up to the problem. Community-based health workers such as Accredited Social Health Activist are a good dependable force in India and are needed to be trained in awareness and establishing a proper identification for prompt referral. ROP prevention needs a multidisciplinary team approach. ROP management stands as a good example of all the strategies for prevention, which includes primary prevention (improving obstetric and neonatal care), secondary prevention (screening and treatment programs), and tertiary prevention (treating complications and rehabilitation to reduce disability). Given its demographic and cultural diversity, India faces numerous challenges, with significant rural-urban, poor-rich, gender, socioeconomic, and regional differences. So, we need to gear up to face the present challenge of the third epidemic of ROP and prevent ROP-related childhood blindness as it is the need of the hour.

Validation of the diagnosis of necrotising enterocolitis in a Swedish population-based observational study

Aim

The definition of necrotising enterocolitis (NEC) is based on clinical and radiological signs that can be difficult to interpret. The aim of the present study was to validate the incidence of NEC in the Extremely Preterm Infants in Sweden Study (EXPRESS)

Methods

The EXPRESS study consisted of all 707 infants born before 27 + 0 gestational weeks during the years 2004–2007 in Sweden. Of these infants, 38 were recorded as having NEC of Bell stage II or higher. Hospital records were obtained for these infants. Furthermore, to identify missed cases, all infants with a sudden reduction of enteral nutrition, in the EXPRESS study were identified (n = 71). Hospital records for these infants were obtained. Thus, 108 hospital records were obtained and scored independently by two neonatologists for NEC.

Results

Of 38 NEC cases in the EXPRESS study, 26 were classified as NEC after validation. Four cases not recorded in the EXPRESS study were found. The incidence of NEC decreased from 6.3% to 4.3%.

Conclusion

Validation of the incidence of NEC revealed over‐ and underestimation of NEC in the EXPRESS study despite carefully collected data. Similar problems may occur in other national data sets or quality registers.

Early extubation is not associated with severe intraventricular hemorrhage in preterm infants born before 29 weeks of gestation. Results of an EPIPAGE-2 cohort study

Objective

To determine whether there is an association between severe intraventricular hemorrhage and early extubation in preterm infants born before 29 weeks of gestational age and intubated at birth.

Methods

This study included 1587 preterm infants from a nationwide French population cohort (EPIPAGE-2). Secondary data on intubated preterm infants were analyzed. After gestational age and propensity score matching (1:1) we built two comparable groups: an early extubation group and a delayed extubation group. Each neonate in one group was paired with a neonate in the other group having the same propensity score and gestational age. Early extubation was defined as extubation within 48 hours of life. Severe intraventricular hemorrhages were defined as grade III or IV hemorrhages according to the Papile classification.

Results

After matching, there were 398 neonates in each group. Using a generalized estimating equation model, we found that intraventricular hemorrhage was not associated with early extubation (adjusted OR 0.9, 95%CI 0.6–1.4). This result was supported by sensitivity analyses.

Conclusion

The practice of early extubation was not associated with an increased proportion of intraventricular hemorrhages. To complete these results, the long-term neurologic outcomes of these infants need to be assessed.

Trends in epidemiology and outcomes of respiratory distress syndrome in the United States

BACKGROUND

The management practices of Respiratory Distress Syndrome (RDS) in the newborn have changed over time. We examine the trends in the epidemiology, resource utilization, and outcomes (mortality and bronchopulmonary dysplasia [BPD]) of RDS in preterm neonates ≤34 weeks gestational age (GA) in the United States.

METHODS

In this retrospective serial cross-sectional study, we used ICD-9 codes to classify preterm infants GA ≤34 weeks between 2003 and 2014 from the National Inpatient Sample as having RDS or not. Trends in the prevalence of infants defined as RDS by ICD-9 code (ICD9-RDS), length of stay, BPD, and mortality were analyzed using Cochran-Armitage and Jonckheere-Terpstra tests and multivariable logistic regression.

RESULTS

Of 1 526 186 preterm live births with GA ≤34 weeks, 554 409 had ICD9-RDS (260 cases per 1000 live births) with the prevalence increasing from 170 to 361 (P_trend  < 0.001) and associated decrease in all-cause mortality (7.6% to 6.1%; P_trend  < 0.001) from 2003 to 2014. Increased utilization of non-invasive mechanical ventilation (NIMV) (69.5% to 74.3%; P_trend  < 0.001) was associated with decreased invasive mechanical ventilation (IMV) use >96 h (60.4 to 56.6%; P_trend  < 0.001). Exclusive NIMV use increased from 16.8% to 29.1% (P_trend  < 0.0001). BPD incidence decreased from 14% to 12.5% (P_trend  < 0.001). LOS increased from 32 days to 38 days (P_trend  < 0.001) and cost increased from $49,521 to $55,394 (P_trend  < 0.001).

CONCLUSION

From 2003 to 2014, the assigned ICD9-RDS diagnosis, and utilization of NIMV increased and mortality among infants assigned the ICD9-RDS diagnosis decreased. With higher survival, hospital cost increased incrementally, indicating the importance of ongoing analysis of appropriate reimbursement for the care provided at tertiary centers for preterm infants.

Human milk as a protective factor for bronchopulmonary dysplasia: a systematic review and meta-analysis

OBJECTIVE

To summarise current evidence evaluating the effects of human milk on the risk of bronchopulmonary dysplasia (BPD) in preterm infants.

DESIGN

We searched for studies on human milk and BPD in English and Chinese databases on 26 July 2017. Furthermore, the references of included studies were also screened. The inclusion criteria in this meta-analysis were the following: (1) preterm infants (<37 weeks); (2) human milk; (3) comparing with formula feeding; (4) the outcome included BPD; and (5) the type of study was randomised controlled trial (RCT) or cohort study.

RESULT

A total of 17 cohort studies and 5 RCTs involving 8661 preterm infants met our inclusion criteria. The ORs and 95% CIs of six groups were as follows: 0.78 (0.68 to 0.88) for exclusive human milk versus exclusive formula group, 0.77 (0.68 to 0.87) for exclusive human milk versus mainly formula group, 0.76 (0.68 to 0.87) for exclusive human milk versus any formula group, 0.78 (0.68 to 0.88) for mainly human milk versus exclusive formula group, 0.83 (0.69 to 0.99) for mainly human milk versus mainly formula group and 0.82 (0.73 to 0.93) for any human milk versus exclusive formula group. Notably, subgroup of RCT alone showed a trend towards protective effect of human milk on BPD but no statistical significance.

CONCLUSION

Both exclusive human milk feeding and partial human milk feeding appear to be associated with lower risk of BPD in preterm infants. The quality of evidence is low. Therefore, more RCTs of this topic are needed.

Towards a unified perinatal theory: Reconciling the births-based and fetus-at-risk models of perinatal mortality

BACKGROUND

There is a need to reconcile the opposing perspectives of the births-based and fetuses-at-risk models of perinatal mortality and to formulate a coherent and unified perinatal theory.

METHODS

Information on births in the United States from 2004 to 2015 was used to calculate gestational age-specific perinatal death rates for low- and high-risk cohorts. Cubic splines were fitted to the fetuses-at-risk birth and perinatal death rates, and first and second derivatives were estimated. Births-based perinatal death rates, and fetuses-at-risk birth and perinatal death rates and their derivatives, were examined to identify potential inter-relationships.

RESULTS

The rate of change in the birth rate dictated the pattern of births-based perinatal death rates in a triphasic manner: increases in the first derivative of the birth rate at early gestation corresponded with exponential declines in perinatal death rates, the peak in the first derivative presaged the nadir in perinatal death rates, and late gestation declines in the first derivative coincided with an upturn in perinatal death rates. Late gestation increases in the first derivative of the fetuses-at-risk perinatal death rate matched the upturn in births-based perinatal death rates. Differences in birth rate acceleration/deceleration among low- and high-risk cohorts resulted in intersecting perinatal mortality curves.

CONCLUSION

The first derivative of the birth rate links a cohort's fetuses-at-risk perinatal death rate to its births-based perinatal death rate, and cohort-specific differences in birth rate acceleration/deceleration are responsible for the intersecting perinatal mortality curves paradox. This mechanistic explanation unifies extant models of perinatal mortality and provides diverse insights.

Neonatal Outcomes of Very Low Birth Weight Infants in Korean Neonatal Network from 2013 to 2016

BACKGROUND

This study was performed to determine survival and morbidity rates in very low birth weight infants (VLBWIs) in the Korean Neonatal Network (KNN), and to compare neonatal outcomes with those in other countries.

METHODS

Data were collected for 8,269 VLBWIs with gestational age (GA) ≥ 22 weeks who were born between January 1, 2013 and December 31, 2016, and admitted to the neonatal intensive care units of the KNN.

RESULTS

The survival rate of all VLBWIs and of infants with GA 22-23, 24-25, 26-27, 28-29, 30-32, and > 32 weeks were 86% (total), 33%, 65%, 84%, 94%, 97%, and 98%, respectively. The bronchopulmonary dysplasia (BPD) rates of all VLBWIs and of infants with GA 22-23, 24-25, 26-27, 28-29, 30-32, and > 32 weeks were 30% (total), 88%, 64%, 47%, 26%, 14%, and 5%, respectively. The intraventricular hemorrhage rates (≥ grade III) of all VLBWIs and of infants with GA 22-23, 24-25, 26-27, 28-29, 30-32, and > 32 weeks were 10% (total), 45%, 27%, 12%, 5%, 2%, and 1%, respectively. In an international comparison, the survival rate of VLBWIs with GA 24-27 weeks in KNN was lower, and the BPD rate of VLBWIs in the KNN was higher than that of the neonatal networks of other countries.

CONCLUSION

Despite overall improvements in neonatal outcomes, the survival and morbidity rates of more immature infants with GA 22-27 weeks need further improvement. Therefore, it would be necessary to develop more optimal treatment strategies and perform more active quality improvement to further improve neonatal outcomes of VLBWIs in Korea.

Oscillatory respiratory mechanics on the first day of life improves prediction of respiratory outcomes in extremely preterm newborns

BACKGROUND

We aimed to evaluate if lung mechanics measured by forced oscillatory technique (FOT) during the first day of life help identify extremely low gestational age newborns (ELGANs) at risk of prolonged mechanical ventilation (MV) and oxygen dependency.

METHODS

Positive end-expiratory pressure (PEEP) was increased 2 cmH₂O above the clinically set PEEP, then decreased by four 5-min steps of 1 cmH₂O, and restored at the clinical value. At each PEEP, FOT measurements were performed bedside during MV. Changes in respiratory mechanics with PEEP, clinical parameters, and chest radiographs were evaluated.

RESULTS

Twenty-two newborns (24⁺⁴ ± 1⁺⁴ wks gestational age (GA); birth weight 653 ± 166 g) on assist/control ventilation were studied. Infants were ventilated for 40 ± 36 d (range 1-155 d), 11 developed severe bronchopulmonary dysplasia (BPD) and one died before 28 d. Early lung mechanics correlated with days on MV, days of respiratory support, and BPD grade. Effects of increasing PEEP on oscillatory reactance assessed by FOT together with GA and radiographic score predicted days on MV (multilinear model, r² = 0.73). A logistic model considering the same FOT parameter together with GA predicts BPD development.

CONCLUSIONS

FOT can be applied bedside in ELGANs, where early changes in lung mechanics with PEEP improve clinical prediction of respiratory outcomes.

A population-based comparison of preterm neonatal deaths (22-34 gestational weeks) in France and Ontario: a cohort study

BACKGROUND

The management and outcomes of preterm births can vary greatly even among developed nations with the same access to medicine, technology and expertise. We aimed to compare aspects of obstetrical management and mortality for preterm infants in France and Ontario, Canada.

METHODS

The Better Outcomes Registry & Network (BORN) Information System in Ontario and Épidémiologique sur les petits âges gestationnels (EPIPAGE-2) in France collected information on maternal demographics, obstetrical characteristics, obstetrical interventions and neonatal outcomes for infants born between 22 and 34 weeks gestation. We used standardized covariate definitions and extracted data from 2011 (for EPIPAGE-2) and from 2012 and 2013 (for BORN) to conduct a cohort study comparing the 2 data sets (stratified into gestational age groups of 22-26, 27-31 and 32-34 wk) using multivariable logistic regression models.

RESULTS

Mothers in the BORN cohort were older (30.7 yr v. 29.6 yr) but less likely to have gestational hypertension (13.4% v. 17.9%) than those in the EPIPAGE-2 cohort. Infants from EPIPAGE-2 had lower birth weights (1.3 kg v. 1.5 kg) and were more likely to be born in an institution with level 3 care (71.9% v. 55.8%). After adjustment for these differences, there was significantly higher neonatal mortality among infants from EPIPAGE-2 in the 22-26 week gestation age group (adjusted odds ratio 2.81; 95% confidence interval 1.17 to 6.74).

INTERPRETATION

Even after we adjusted for both intrinsic population differences and differences in management between Ontario and France, we found a higher rate of neonatal mortality at earlier gestational ages in France. This may be related to differences in ethical approaches and/or postnatal management and should be explored further.

Unit-Level Variations in Healthcare Professionals' Availability for Preterm Neonates <29 Weeks' Gestation: An International Survey

INTRODUCTION

The availability of and variability in healthcare professionals in neonatal units in different countries has not been well characterized. Our objective was to identify variations in the healthcare professionals for preterm neonates in 10 national or regional neonatal networks participating in the International Network for Evaluating Outcomes (iNeo) of neonates.

METHOD

Online, pre-piloted questionnaires about the availability of healthcare professionals were sent to the directors of 390 tertiary neonatal units in 10 international networks: Australia/New Zealand, Canada, Finland, Illinois, Israel, Japan, Spain, Sweden, Switzerland, and Tuscany.

RESULTS

Overall, 325 of 390 units (83%) responded. About half of the units (48%; 156/325) cared for 11-30 neonates/day and had team-based (43%; 138/325) care models. Neonatologists were present 24 h a day in 59% of the units (191/325), junior doctors in 60% (194/325), and nurse practitioners in 36% (116/325). A nurse-to-patient ratio of 1:1 for infants who are unstable and require complex care was used in 52% of the units (170/325), whereas a ratio of 1:1 or 1:2 for neonates requiring multisystem support was available in 59% (192/325) of the units. Availability of a respiratory therapist (15%, 49/325), pharmacist (40%, 130/325), dietitian (34%, 112/325), social worker (81%, 263/325), lactation consultant (45%, 146/325), parent buddy (6%, 19/325), or parents' resource personnel (11%, 34/325) were widely variable between units.

CONCLUSIONS

We identified variability in the availability and organization of the healthcare professionals between and within countries for the care of extremely preterm neonates. Further research is needed to associate healthcare workers' availability and outcomes.

Neonatal outcomes of very low birthweight infants born to mothers with hyperglycaemia in pregnancy: a retrospective cohort study in Japan

OBJECTIVE

To examine the mortality and morbidities of very low birthweight (VLBW, <1500 g) infants of mothers with hyperglycaemia in pregnancy.

DESIGN AND SETTING

We conducted a retrospective cohort study using data from the Neonatal Research Network of Japan, a nationwide registry of VLBW infants (2003-2012).

PATIENTS

We studied 29 626 infants born at 23 to 32 weeks without major congenital anomalies, of which 682 (2.3%) infants were from pregnancies affected by maternal hyperglycaemia.

MAIN OUTCOME MEASURES

The primary outcome was hospital mortality. Secondary outcomes were neonatal morbidities and their anthropometric values. Associations between maternal hyperglycaemia and each outcome were observed for the overall period, and statistical tests for interaction were conducted to assess whether they differed before or after the adoption of the International Association of Diabetes in Pregnancy Study Group (IADPSG) guidelines in 2010 for the diagnosis of gestational diabetes mellitus.

RESULTS

Overall, hospital mortality (4.1% vs 5.2%), composite outcomes of mortality and severe morbidity (54.2% vs 60%), and anthropometric values were not significantly different between infants of mothers with or without hyperglycaemia in pregnancy. However, the incidence of respiratory distress syndrome (RDS) in VLBW infants from mothers with hyperglycaemia was significantly higher than those from mothers without it only before (relative risk (RR) 1.09, 95% CI 1.00 to 1.19) and not after (RR 0.97, 95% CI 0.83 to 1.11) the adoption of the IADPSG guidelines.

CONCLUSION

VLBW infants born to mothers with hyperglycaemia in pregnancy do not seem to be at higher risk of mortality and morbidities, except for RDS only before the adoption of the IADPSG guidelines.

Wide variation in severe neonatal morbidity among very preterm infants in European regions

OBJECTIVE

To investigate the variation in severe neonatal morbidity among very preterm (VPT) infants across European regions and whether morbidity rates are higher in regions with low compared with high mortality rates.

DESIGN

Area-based cohort study of all births before 32 weeks of gestational age.

SETTING

16 regions in 11 European countries in 2011/2012.

PATIENTS

Survivors to discharge from neonatal care (n=6422).

MAIN OUTCOME MEASURES

Severe neonatal morbidity was defined as intraventricular haemorrhage grades III and IV, cystic periventricular leukomalacia, surgical necrotizing enterocolitis and retinopathy of prematurity grades ≥3. A secondary outcome included severe bronchopulmonary dysplasia (BPD), data available in 14 regions. Common definitions for neonatal morbidities were established before data abstraction from medical records. Regional severe neonatal morbidity rates were correlated with regional in-hospital mortality rates for live births after adjustment on maternal and neonatal characteristics.

RESULTS

10.6% of survivors had a severe neonatal morbidity without severe BPD (regional range 6.4%-23.5%) and 13.8% including severe BPD (regional range 10.0%-23.5%). Adjusted inhospital mortality was 13.7% (regional range 8.4%-18.8%). Differences between regions remained significant after consideration of maternal and neonatal characteristics (P<0.001) and severe neonatal morbidity rates were not correlated with mortality rates (P=0.50).

CONCLUSION

Severe neonatal morbidity rates for VPT survivors varied widely across European regions and were independent of mortality rates.

Neonatal Outcomes of Very Preterm or Very Low Birth Weight Triplets

OBJECTIVES

To compare the neonatal outcomes of very preterm triplets with those of matched singletons using a large international cohort.

METHODS

A retrospective matched-cohort study of preterm triplets and singletons born between 2007 and 2013 in the International Network for Evaluation of Outcomes in neonates database countries and matched by gestational age, sex, and country of birth was conducted. The primary outcome was a composite of mortality or severe neonatal morbidity (severe neurologic injury, treated retinopathy of prematurity, and bronchopulmonary dysplasia). Unadjusted and adjusted odds ratios with 95% confidence intervals (CIs) were calculated for model 1 (maternal hypertension and birth weight z score) and model 2 (variables in model 1, antenatal steroids, and mode of birth). Models were fitted with generalizing estimating equations and random effects modeling to account for clustering.

RESULTS

A total of 6079 triplets of 24 to 32 weeks' gestation or 500 to 1499 g birth weight and 18 232 matched singletons were included. There was no difference in the primary outcome between triplets and singletons (23.4% vs 24.0%, adjusted odds ratio: 0.91, 95% CI: 0.83-1.01 for model 1 and 1.00, 95% CI: 0.90-1.11 for model 2). Rates of severe neonatal morbidities did not differ significantly between triplets and singletons. The results were also similar for a subsample of the cohort (1648 triplets and 4944 matched singletons) born at 24 to 28 weeks' gestation.

CONCLUSIONS

No significant differences were identified in mortality or major neonatal morbidities between triplets who were very low birth weight or very preterm and matched singletons.

Gestational Age, Health, and Educational Outcomes in Adolescents

BACKGROUND AND OBJECTIVES

As outcomes for extremely premature infants improve, up-to-date, large-scale studies are needed to provide accurate, contemporary information for clinicians, families, and policy makers. We used nationwide New Zealand data to explore the impact of gestational age on health and educational outcomes through to adolescence.

METHODS

We performed a retrospective cohort study of all births in New Zealand appearing in 2 independent national data sets at 23 weeks' gestation or more. We report on 2 separate cohorts: cohort 1, born January 1, 2005 to December 31, 2015 (613 521 individuals), used to study survival and midterm health and educational outcomes; and cohort 2, born January 1, 1998 to December 31, 2000, and surviving to age 15 years (146 169 individuals), used to study high school educational outcomes. Outcomes described by gestational age include survival, hospitalization rates, national well-being assessment outcomes at age 4 years, rates of special education support needs in primary school, and national high school examination results.

RESULTS

Ten-year survival increased with gestational age from 66% at 23 to 24 weeks to >99% at term. All outcomes measured were strongly related to gestational age. However, most extremely preterm children did not require special educational support and were able to sit for their national high school examinations.

CONCLUSIONS

Within a publicly funded health system, high-quality survival is achievable for most infants born at periviable gestations. Outcomes show improvement with gestational ages to term. Outcomes at early-term gestation are poorer than for children born at full term.

Gene expression profiling of postnatal lung development in the marsupial gray short-tailed opossum (Monodelphis domestica) highlights conserved developmental pathways and specific characteristics during lung organogenesis

BACKGROUND

After a short gestation, marsupials give birth to immature neonates with lungs that are not fully developed and in early life the neonate partially relies on gas exchange through the skin. Therefore, significant lung development occurs after birth in marsupials in contrast to eutherian mammals such as humans and mice where lung development occurs predominantly in the embryo. To explore the mechanisms of marsupial lung development in comparison to eutherians, morphological and gene expression analysis were conducted in the gray short-tailed opossum (Monodelphis domestica).

RESULTS

Postnatal lung development of Monodelphis involves three key stages of development: (i) transition from late canalicular to early saccular stages, (ii) saccular and (iii) alveolar stages, similar to developmental stages overlapping the embryonic and perinatal period in eutherians. Differentially expressed genes were identified and correlated with developmental stages. Functional categories included growth factors, extracellular matrix protein (ECMs), transcriptional factors and signalling pathways related to branching morphogenesis, alveologenesis and vascularisation. Comparison with published data on mice highlighted the conserved importance of extracellular matrix remodelling and signalling pathways such as Wnt, Notch, IGF, TGFβ, retinoic acid and angiopoietin. The comparison also revealed changes in the mammalian gene expression program associated with the initiation of alveologenesis and birth, pointing to subtle differences between the non-functional embryonic lung of the eutherian mouse and the partially functional developing lung of the marsupial Monodelphis neonates. The data also highlighted a subset of contractile proteins specifically expressed in Monodelphis during and after alveologenesis.

CONCLUSION

The results provide insights into marsupial lung development and support the potential of the marsupial model of postnatal development towards better understanding of the evolution of the mammalian bronchioalveolar lung.

Evaluation index for asymmetric ventricular size on brain magnetic resonance images in very low birth weight infants

OBJECTIVE

Asymmetric ventriculomegaly is often evident on brain magnetic resonance imaging (MRI) in very low birth weight infants (VLBWI) and is interpreted as white matter injury. However, no evaluation index for asymmetric left-right and anterior-posterior ventricular sizes has been established.

METHODS

In this retrospective multicenter cohort study, brain T2-weighted MRI was performed at term-equivalent ages in 294 VLBWI born between 2009 and 2011. The value of a lateral ventricular index (LVI) to evaluate asymmetric ventricular size, as well as the relationship between the LVI value and walking at a corrected age of 18 months was investigated. At the level of the foramen of Monro in a horizontal slice, asymmetry between the left and right sides and between the anterior and posterior horns was identified by the corrected width and was detected by a low concordance rate and κ statistic value. An LVI representing the sum of the widths of the four horns of the lateral ventricle corrected for cerebral diameter was devised.

RESULTS

Asymmetric left-right and anterior-posterior ventricular sizes were confirmed. The LVI value was significantly higher in the non-walking VLBWI group (n = 39) than in the walking VLBWI group (n = 255; 18.2 vs. 15.8, p = 0.02). An LVI cut-off value of 21.5 was associated with non-walking. Multivariate analysis revealed that an LVI value >21.5 was an independent predictor of walking disability at the corrected age of 18 months (odds ratio 2.56, p = 0.008).

CONCLUSIONS

The LVI value calculated via MRI may predict walking disability at a corrected age of 18 months in VLBWI.

Hyperbilirubinemia in preterm infants in Japan: New treatment criteria

In 1992, Kobe University proposed treatment criteria for hyperbilirubinemia in newborns using total serum bilirubin and serum unbound bilirubin reference values. In the last decade, chronic bilirubin encephalopathy has been found to develop in preterm infants in Japan because it can now be clinically diagnosed based on an abnormal signal of the globus pallidus on T2-weighted magnetic resonance imaging and abnormal auditory brainstem response with or without apparent hearing loss, along with physical findings of kinetic disorders with athetosis. We therefore revised the Kobe University treatment criteria for preterm hyperbilirubinemic infants in 2017. The three revised points are as follows: (i) newborns are classified under gestational age at birth or corrected gestational age, not birthweight; (ii) three treatment options were created: standard phototherapy, intensive phototherapy, and albumin therapy and/or exchange blood transfusion; and (iii) initiation of standard phototherapy, intensive phototherapy, and albumin therapy and/or exchange blood transfusion is decided based on the total serum bilirubin and serum unbound bilirubin reference values for gestational weeks at birth at <7 days of age, and on the reference values for corrected gestational age at ≥7 days of age. Studies are needed to establish whether chronic bilirubin encephalopathy can be prevented using the 2017 revised Kobe University treatment criteria for preterm infants in Japan.

Extremely premature infants: How does death in the delivery room influence mortality rates in two level 3 centers in France?

OBJECTIVES

Mortality rates of very preterm infants may vary considerably between healthcare facilities depending on the neonates' place of inclusion in the cohort study. The objective of this study was to compare the mortality rates of live-born extremely preterm neonates observed in two French tertiary referral hospitals, taking into account the occurrence of neonatal death both in the delivery room and in the neonatal intensive care unit (NICU).

METHODS

Retrospective observational study including all pregnancy terminations, stillbirths and live-born infants within a 22- to 26-week ^0/6 gestational age range was registered by two French level 3 university centers between 2009 and 2013. The mortality rates were compared between the two centers according to two places of inclusion: either the delivery room or the NICU.

RESULTS

A total of 344 infants were born at center A and 160 infants were born at center B. Among the live-born neonates, the rates of neonatal death were similar in center A (54/125, 43.2%) and center B (33/69, 47.8%; P=0.54). However, neonatal death occurred significantly more often in the delivery room at center A (31/54, 57.4%) than at center B (6/33, 18.2%; P<0.001). Finally, the neonatal death rate of live-born very preterm neonates admitted to the NICU was significantly lower in center A (25/94, 26.6%) than in center B (27/63, 42.9%; P=0.03).

CONCLUSIONS

This study points out how the inclusion of deaths in the delivery room when comparing neonatal death rates can lead to a substantial bias in benchmarking studies. Center A and center B each endorsed one of the two models of preferential place of neonatal death (delivery room or NICU) detailed in European studies. The reasons behind the two different models and their impact on how parents perceive supporting their neonate need further investigation.

Incidence of retinopathy of prematurity (ROP) and ROP treatment in Switzerland 2006-2015: a population-based analysis

BACKGROUND

Retinopathy of prematurity (ROP) is a severe complication of preterm birth and can lead to severe visual impairment or even blindness if untreated. The incidence of ROP requiring treatment is increasing in some developed countries in conjunction with higher survival rates at the lower end of gestational age (GA).

MATERIAL AND METHODS

The incidence of ROP and severe ROP (sROP) requiring treatment in Switzerland was analysed using the SwissNeoNet registry. We conducted a retrospective cohort analysis of very preterm infants with a GA below 32 weeks who were born between 2006 and 2015 in Switzerland. Patient characteristics were stratified according to GA.

RESULTS

9.3% and 1.8% of very preterm infants in Switzerland developed ROP of any stage and sROP, respectively. The incidence of ROP treatment was 1.2%. Patients with 24 and 25 weeks GA had the highest proportion of ROP treatment at 14.5% and 7.3%, respectively, whereas the proportion of treated infants at or above a GA of 29 weeks was 0.06%. Similarly, the risk of sROP declined strongly with increasing GA. During the observation period of 10 years, the incidence of ROP treatment ranged between 0.8% and 2.0%. Incidences of sROP or ROP treatment did not increase over time.

CONCLUSION

The incidence of ROP treatment in Switzerland is low and was stable over the analysed period. The low incidence of sROP in patients with a GA of 29 weeks or more leaves room for a redefinition of ROP screening criteria.

An International Comparison of Death Classification at 22 to 25 Weeks' Gestational Age

OBJECTIVES

To explore international differences in the classification of births at extremely low gestation and the subsequent impact on the calculation of survival rates.

METHODS

We used national data on births at 22 to 25 weeks' gestation from the United States (2014; n = 11 144), Canada (2009-2014; n = 5668), the United Kingdom (2014-2015; n = 2992), Norway (2010-2014; n = 409), Finland (2010-2015; n = 348), Sweden (2011-2014; n = 489), and Japan (2014-2015; n = 2288) to compare neonatal survival rates using different denominators: all births, births alive at the onset of labor, live births, live births surviving to 1 hour, and live births surviving to 24 hours.

RESULTS

For births at 22 weeks' gestation, neonatal survival rates for which we used live births as the denominator varied from 3.7% to 56.7% among the 7 countries. This variation decreased when the denominator was changed to include stillbirths (ie, all births [1.8%-22.3%] and fetuses alive at the onset of labor [3.7%-38.2%]) or exclude early deaths and limited to births surviving at least 12 hours (50.0%-77.8%). Similar trends were seen for infants born at 23 weeks' gestation. Variation diminished considerably at 24 and 25 weeks' gestation.

CONCLUSIONS

International variation in neonatal survival rates at 22 to 23 weeks' gestation diminished considerably when including stillbirths in the denominator, revealing the variation arises in part from differences in the proportion of births reported as live births, which itself is closely connected to the provision of active care.

Trends in the neurodevelopmental outcomes among preterm infants from 2003-2012: a retrospective cohort study in Japan

OBJECTIVES

To determine the trends in mortality and the prevalence of abnormal neurodevelopmental outcomes among preterm Japanese infants.

STUDY DESIGN

A retrospective multicenter cohort of 30,793 preterm infants born at a gestational age ≤32 weeks, between 2003 and 2012, in the Neonatal Research Network, Japan, was evaluated in the primary analysis. Finally, 13,661 infants were followed-up until 3 years of age and evaluated for neurodevelopmental outcomes, including cerebral palsy (CP), home oxygen therapy (HOT) use, and visual, hearing, and cognitive impairments. Multivariable logistic regression analysis was performed to determine the risk-adjusted trends in mortality and long-term neurodevelopmental outcomes.

RESULTS

The trends in overall mortality (adjusted odds ratio, (AOR): 0.92; 95% confidence interval, (CI): 0.89-0.94), the prevalence of CP (AOR: 0.95, 95% CI: 0.92-0.98), HOT use (AOR: 0.84, 95% CI: 0.75-0.93), and visual (AOR: 0.84, 95% CI: 0.81-0.87) and hearing impairments (AOR: 0.78, 95% CI: 0.63-0.97) showed a significant downward trend, while cognitive impairment showed no significant changes (AOR: 1.02, 95% CI: 0.99-1.05). Intravenous hyperalimentation was significantly correlated with visual impairment (AOR 0.74, 95% CI 0.59-0.91). Early establishment of enteral feeding was associated with improved long-term outcomes.

CONCLUSIONS

Mortality was improved, and this did not lead to increased risks for abnormal neurodevelopmental outcomes. Nutritional support might improve long-term neurodevelopmental outcomes.

A Prospective Study of Causes of Illness and Death in Preterm Infants in Ethiopia: The SIP Study Protocol

BACKGROUND

With nearly 15 million annual preterm births globally, preterm birth is the most common cause of neonatal death. Forty to 60 % of neonatal deaths are directly or indirectly associated with preterm mortality. As countries aim to meet the Sustainable Development Goals to reduce neonatal mortality, significant reductions in preterm mortality are needed. This study aims to identify the common causes of preterm illness and their contribution to preterm mortality in low-resource settings. This article will describe the methods used to undertake the study.

METHODS

This is a prospective, multi-centre, descriptive clinical study. Socio-demographic, obstetric, and maternal factors, and clinical and laboratory findings will be documented. The major causes of preterm mortality will be identified using clinical, laboratory, imaging, and autopsy methods and use the national Ethiopian guidelines on management of preterm infants including required investigations to reach final diagnoses. The study will document the clinical and management protocols followed in these settings. The approach consists of clinical examinations and monitoring, laboratory investigations, and determination of primary and contributory causes of mortality through both clinical means and by post-mortem examinations. An independent panel of experts will validate the primary and contributory causes of mortality. To obtain the estimated sample size of 5000 preterm births, the study will be undertaken in five hospitals in three regions of Ethiopia, which are geographically distributed across the country. All preterm infants who are either born or transferred to these hospitals will be eligible for the study. Three methods (last menstrual period, physical examination using the New Ballard Score, and ultrasound) will be used to determine gestational age. All clinical procedures will be conducted per hospital protocol and informed consent will be taken from parents or caretakers prior to their participation in the study as well as for autopsy if the infant dies.

DISCUSSION

This study will determine the major causes of death and illness among hospitalized preterm infants in a low-resource setting. The result will inform policy makers and implementers of areas that can be prioritized in order to contribute to a significant reduction in neonatal mortality.

Socioeconomic inequity in survival for deliveries at 22-24 weeks of gestation

OBJECTIVE

Guidelines recommend individual decision making on resuscitating infants of 22-24 weeks' gestational age (GA) at birth. When the decision not to resuscitate is made, infants would likely die soon after delivery, and under some circumstances such neonatal deaths may be registered as stillbirths occurring during delivery (intrapartum stillbirth). Thus we assessed whether socioeconomic factors are associated with peridelivery deaths (during or within 1 hour of delivery) of infants delivered at 22-24 weeks' gestation.

METHODS

We analysed 14 726 singletons of 22-24 weeks' GA using the 2003-2011 Japanese vital statistics, and assessed how maternal characteristics influence risk of peridelivery death as well as intrauterine fetal death (IUFD) and death after 1 hour of age until 40 weeks postmenstrual age.

RESULTS

Living in a municipality with low-average income (lowest tertile (risk ratio 1.32, 95% CI 1.20 to 1.44), middle tertile (risk ratio 1.08, 95% CI 0.98 to 1.19)), younger maternal age (age <20 (risk ratio 1.43, 95% CI 1.17 to 1.75), age 20-34 (risk ratio 1.14, 95% CI 1.03 to 1.27)) and having previous live births (risk ratio 1.08, 95% CI 1.01 to 1.17) increased risk of peridelivery deaths, but did not increase risk of IUFD or deaths after 1 hour of age. Peridelivery death was twice as likely to occur in births to multiparous teenage mothers in a low-income municipality, compared with those of older primiparous mothers in a wealthier municipality.

CONCLUSIONS

Socioeconomic factors substantially influence whether births of 22-24 weeks' GA survive delivery and the first hour of life. Such disparities may reflect the impact of socioeconomic situations on decision making for resuscitation.

Maternal Vaccination as an Essential Component of Life-Course Immunization and Its Contribution to Preventive Neonatology

Maternal immunisation schedules are increasingly coming under the spotlight as part of the development of lifetime immunisation programmes for the role that they play in improving maternal, foetal, and neonatal health. Maternally-acquired antibodies are critical in protecting infants during the first months of their lives. Maternal immunisation was previously overlooked owing to concerns regarding vaccinations in this untested and high-risk population but is now acknowledged for its potential impact on the outcomes in many domains of foetal and neonatal health, aside from its maternal benefits. This article highlights the role that maternal immunisation may play in reducing infections in preterm and term infants. It explores the barriers to antenatal vaccinations and the optimisation of the immunisation uptake. This review also probes the part that maternal immunisation may hold in the reduction of perinatal antimicrobial resistance and the prevention of non-infectious diseases. Both healthcare providers and expectant mothers should continue to be educated on the importance and safety of the appropriate immunizations during pregnancy. Maternal vaccination merits its deserved priority in a life-course immunization approach and it is perhaps the only immunization whereby two generations benefit directly from a single input. We outline the current recommendations for antenatal vaccinations and highlight the potential advances in the field contributing to “preventive neonatology”.

Drug evaluation studies in neonates: how to overcome the current limitations

INTRODUCTION

Regulatory initiatives have stimulated drug research in infants, but the potential impact of drugs to improve health outcome in neonates remains underexplored. Areas covered: In this review, we focus on current limitations in drug evaluation studies and how to overcome these. The low volume of studies has additional weaknesses such as single center studies, non-commercial sponsorship, overrepresentation of high postulated risk reductions, and underrepresentation of therapeutic exploratory studies. Master protocols and selection criteria for neonatal centers to participate in studies are useful to improve logistics related to performance. Limitations also relate to inaccurate assessment of drug effects (efficacy/safety). This is because of poor symptom recognition, case definitions, and suboptimal data on adverse drug reactions (ADRs) epidemiology. To overcome these limitations, it is necessary to develop core outcome sets, reference values, and specific ADR tools. The limitations identified and approaches suggested to improve drug evaluation are illustrated using neonatal abstinence syndrome as an example. Expert commentary: We anticipate to see an evolving neonatal clinical pharmacology discipline driven by neonatal pathophysiology and knowledge. Multidisciplinary collaborative efforts between health care providers, academia, pharmaceutical industry, advocacy groups and regulatory agencies are crucial to improve the impact of drug evaluation studies in neonates.

Systemic Hydrocortisone To Prevent Bronchopulmonary Dysplasia in preterm infants (the SToP-BPD study): statistical analysis plan

Background

Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth with short-term and long-term adverse consequences. Although the glucocorticoid dexamethasone has been proven to be beneficial for the prevention of BPD, there are concerns about an increased risk of adverse neurodevelopmental outcome. Hydrocortisone has been suggested as an alternative therapy. The aim of the Systemic Hydrocortisone To Prevent Bronchopulmonary Dysplasia in preterm infants (SToP-BPD) trial is to assess the efficacy and safety of postnatal hydrocortisone administration for the reduction of death or BPD in ventilator-dependent preterm infants.

Methods/design

The SToP-BPD study is a multicentre, double-blind, placebo-controlled hydrocortisone trial in preterm infants at risk for BPD. After parental informed consent is obtained, ventilator-dependent infants are randomly allocated to hydrocortisone or placebo treatment during a 22-day period. The primary outcome measure is the composite outcome of death or BPD at 36 weeks postmenstrual age. Secondary outcomes are short-term effects on pulmonary condition and long-term neurodevelopmental sequelae assessed at 2 years corrected age. Complications of treatment, other serious adverse events and suspected unexpected serious adverse reactions are reported as safety outcomes. This pre-specified statistical analysis plan was written and submitted without knowledge of the unblinded data.

Trial registration

Netherlands Trial Register, NTR2768. Registered on 17 February 2011. EudraCT, 2010-023777-19. Registered on 2 November 2010.

Association of nursing overtime, nurse staffing and unit occupancy with medical incidents and outcomes of very preterm infants

OBJECTIVE

To examine the association of nursing overtime, nursing provision and unit occupancy rate with medical incident rates in the neonatal intensive care unit (NICU) and the risk of mortality or major morbidity among very preterm infants.

STUDY DESIGN

Single center retrospective cohort study of infants born within 23 to 29 weeks of gestational age or birth weight <1000 g admitted at a 56 bed, level III NICU. Nursing overtime ratios (nursing overtime hours/total nursing hours), nursing provision ratios (nursing hours/recommended nursing hours based on patient dependency categories) and unit occupancy rates were pooled for all shifts during NICU hospitalization of each infant. Log-binomial models assessed their association with the composite outcome (mortality or major morbidity).

RESULTS

Of the 257 infants that met the inclusion criteria, 131 (51%) developed the composite outcome. In the adjusted multivariable analyses, high (>3.4%) relative to low nursing overtime ratios (⩽3.4%) were not associated with the composite outcome (relative risk (RR): 0.93; 95% confidence interval (CI): 0.86 to 1.02). High nursing provision ratios (>1) were associated with a lower risk of the composite outcome relative to low ones (⩽1) (RR: 0.81; 95% CI: 0.74 to 0.90). NICU occupancy rates were not associated with the composite outcome (RR: 0.98; 95% CI: 0.89 to 1.07, high (>100%) vs low (⩽100%)). Days with high nursing provision ratios (>1) were also associated with lower risk of having medical incidents (RR: 0.91; 95% CI: 0.82 to 0.99).

CONCLUSION

High nursing provision ratio during NICU hospitalization is associated with a lower risk of a composite adverse outcome in very preterm infants.

A Retrospective Database Analysis of Neonatal Morbidities to Evaluate a Composite Endpoint for Use in Preterm Labor Clinical Trials

Objective  To propose and assess a composite endpoint (CE) of neonatal benefit based on neonatal mortality and morbidities by gestational age (GA) for use in preterm labor clinical trials. Study Design  A descriptive, retrospective analysis of the Medical University of South Carolina Perinatal Information System database was conducted. Neonatal morbidities were assessed for inclusion in the CE based on clinical significance/risk of childhood neurodevelopmental impairment, frequency, and association with GA in a mother-neonate linked cohort, comprising women with uncomplicated singleton pregnancies delivered at ≥24 weeks' GA. Results  Among 17,912 mother-neonate pairs, neonates were at a risk of numerous severe but infrequent morbidities. Clinically important, predominantly rare events were combined into a CE comprising neonatal mortality and morbidities, which decreased in frequency with increasing GA. The highest CE frequency occurred at <31 weeks. High frequency of respiratory distress syndrome, bronchopulmonary dysplasia, and sepsis drove the CE. Median length of hospital stay was longer at all GAs in those with the CE compared with those without. Conclusions  Descriptive epidemiological assessment and clinical input were used to develop a CE to measure neonatal benefit, comprising clinically meaningful outcomes. These empirical data and CE allowed trials investigating tocolytics to be sized appropriately.

Respiratory Management of Extremely Preterm Infants: An International Survey

BACKGROUND

There are significant international variations in chronic lung disease rates among very preterm infants yet there is little data on international variations in respiratory strategies.

OBJECTIVE

To evaluate practice variations in the respiratory management of extremely preterm infants born at < 29 weeks' gestational age (GA) among 10 neonatal networks participating in the International Network for Evaluating Outcomes (iNeo) of Neonates collaboration.

METHODS

A web-based survey was sent to the representatives of 390 neonatal intensive care units from Australia/New Zealand, Canada, Finland, Illinois (USA), Israel, Japan, Spain, Sweden, Switzerland, and Tuscany (Italy). Responses were based on practices in 2015.

RESULTS

Overall, 321 of the 390 units responded (82%). The majority of units within networks (40-92%) mechanically ventilate infants born at 23-24 weeks' GA on continuous positive airway pressure (CPAP) with 30-39% oxygen in respiratory distress within 48 h after birth, but the proportion of units that offer mechanical ventilation for infants born at 25-26 weeks' GA at similar settings varied significantly (20-85% of units within networks). The most common respiratory strategy for infants born at 27-28 weeks' GA on CPAP with 30-39% oxygen with respiratory distress within 48 h after birth used by units also varied significantly among networks: mechanical ventilation (0-60%), CPAP (3-82%), intubation and surfactant administration with immediate extubation (0-75%), and less invasive surfactant administration (0-68%).

CONCLUSIONS

There are marked variations but also similarities in respiratory management of extremely preterm infants between networks. Further collaboration and exploration is needed to better understand the association of these variations in practice with pulmonary outcomes.

Survival in Very Preterm Infants: An International Comparison of 10 National Neonatal Networks

OBJECTIVES

To compare survival rates and age at death among very preterm infants in 10 national and regional neonatal networks.

METHODS

A cohort study of very preterm infants, born between 24 and 29 weeks' gestation and weighing <1500 g, admitted to participating neonatal units between 2007 and 2013 in the International Network for Evaluating Outcomes of Neonates. Survival was compared by using standardized ratios (SRs) comparing survival in each network to the survival estimate of the whole population.

RESULTS

Network populations differed with respect to rates of cesarean birth, exposure to antenatal steroids and birth in nontertiary hospitals. Network SRs for survival were highest in Japan (SR: 1.10; 99% confidence interval: 1.08-1.13) and lowest in Spain (SR: 0.88; 99% confidence interval: 0.85-0.90). The overall survival differed from 78% to 93% among networks, the difference being highest at 24 weeks' gestation (range 35%-84%). Survival rates increased and differences between networks diminished with increasing gestational age (GA) (range 92%-98% at 29 weeks' gestation); yet, relative differences in survival followed a similar pattern at all GAs. The median age at death varied from 4 days to 13 days across networks.

CONCLUSIONS

The network ranking of survival rates for very preterm infants remained largely unchanged as GA increased; however, survival rates showed marked variations at lower GAs. The median age at death also varied among networks. These findings warrant further assessment of the representativeness of the study populations, organization of perinatal services, national guidelines, philosophy of care at extreme GAs, and resources used for decision-making.

The impact of premature birth on the permanent tooth size of incisors and first molars

Background

Scientific evidence is insufficient to answer the question of whether premature birth causes altered tooth-crown dimensions.

Objective

To evaluate permanent tooth-crown dimensions in prematurely born children and to compare the findings with full-term born controls.

Subjects and Methods

Preterm children of 8-10 years of age were selected from the Swedish Medical Birth Register. One group consisted of 36 extremely preterm children (born before the 29th gestational week); the other group included 37 very preterm children (born during gestational weeks 29-32). The preterm children were compared with 41 matched full-term born children. Clinical examination and study casts were performed on all children. Permanent maxillary and mandibular first molars, central incisors, and laterals were measured with a digital sliding caliper on study casts. The tooth-crowns were measured both mesio-distal and bucco-lingual.

Results

Both the mesio-distal and bucco-lingual measurements in the maxillary and mandibular first molars had a significantly smaller width in the extremely preterm group compared with the full-term group. The central incisors and lower laterals were significantly smaller mesio-distally in the extremely preterm group compared to the full-term group. A reduction in tooth size of 4-9% was found between the extremely preterm group and the full-term group for both boys and girls. The maxillary first molars and mandibular left first molar were also smaller mesio-distally in the extremely preterm group compared to the very preterm group. The results indicate that the more preterm the birth, the smaller the tooth-crown dimensions. Independent of gestational age girls had generally smaller teeth than boys.

Conclusion

Premature birth is associated with reduced tooth-crown dimensions of permanent incisors and first molars.