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

Standardizing clinician training and patient care in the neonatal neurocritical care: A step-by-step guide

Neonatal neurocritical care (NNCC) has emerged as an important specialty to address neurological conditions affecting newborns including a wide spectrum of brain injuries and developmental impairment. Despite the discipline's growth, variability in NNCC service delivery, patient care, and clinical training poses significant challenges and potentially adversely impacts patient outcomes. Variations in neuroprotective strategies, postnatal care, and training methodologies highlight the urgent need for a unified approach to optimize both short- and long-term neurodevelopmental outcomes for these vulnerable population. This paper presents strategic blueprints for establishing standardized NNCC clinical care and training programs focusing on collaborative effort across medical and allied health professions. By addressing these inconsistencies, the paper proposes that standardizing NNCC practices can significantly enhance the quality of care, streamline healthcare resource utilization, and improve neurodevelopmental outcome, thus paving the way for a new era of neonatal neurological care.

Delivery room intubation and neurodevelopment among extremely preterm infants

BACKGROUND

The impact of delivery room intubation (DRI) on neurodevelopment in extremely preterm infants remains unclear.

METHODS

We retrospectively analyzed data for infants born at 24-27 gestational weeks between 2003 and 2018. The primary outcome was neurodevelopmental impairment (NDI), defined as cerebral palsy or hearing, visual, or cognitive impairment at age 3 years. Secondary outcomes were NDI components and death before and after discharge from the neonatal intensive care unit. We conducted robust Poisson regression analyses, adjusting for perinatal confounders.

RESULTS

The full cohort included 4397 infants with NDI data, of whom 3703 were intubated in the delivery room and 694 were not intubated in the delivery room. The mean gestational age and birth weight were 26.0 ± 1.1 weeks and 778 ± 184 g for infants with DRI and 26.6 ± 1.0 weeks and 873 ± 184 g for infants without DRI. Compared with infants without DRI, those with DRI had a higher risk for NDI (32.4% vs. 23.3%; adjusted risk ratio 1.18, 95% confidence interval: 1.01-1.37). There were no differences in secondary outcomes between infants with and without DRI.

CONCLUSIONS

DRI was associated with an increased risk for NDI at age 3 years among extremely preterm infants.

IMPACT

Few studies have examined the impact of delivery room intubation on neurodevelopment in infants born extremely preterm, and the results have been inconsistent. A total of 4397 infants born at 24-27 gestational weeks who had neurodevelopmental data at age 3 years were included in the present study. The present study found that delivery room intubation was associated with an increased risk for neurodevelopmental impairment at age 3 years among extremely preterm infants.

At the threshold of viability: to resuscitate or not to resuscitate - the perspectives of Israeli neonatologists

OBJECTIVE

This study aims to examine the perspectives of neonatologists in Israel regarding resuscitation of preterm infants born at 22-24 weeks gestation and their consideration of parental preferences. The factors that influence physicians' decisions on the verge of viability were investigated, and the extent to which their decisions align with the national clinical guidelines were determined.

STUDY DESIGN

Descriptive and correlative study using a 47-questions online questionnaire.

RESULTS

90 (71%) of 127 active neonatologists in Israel responded. 74%, 50% and 16% of the respondents believed that resuscitation and full treatment at birth are against the best interests of infants born at 22, 23 and 24 weeks gestation, respectively. Respondents' decisions regarding resuscitation of extremely preterm infants showed significant variation and were consistently in disagreement with either the national clinical guidelines or the perception of what is in the best interest of these newborns. Gender, experience, country of birth and the level of religiosity were all associated with respondents' preferences regarding treatment decisions. Personal values and concerns about legal issues were also believed to affect decision-making.

CONCLUSION

Significant variation was observed among Israeli neonatologists regarding delivery room management of extremely premature infants born at 22-24 weeks gestation, usually with a notable emphasis on respecting parents' wishes. The current national guidelines do not fully encompass the wide range of approaches. The country's guidelines should reflect the existing range of opinions, possibly through a broad survey of caregivers before setting the guidelines and recommendations.

Personalized lung care: Bronchopulmonary dysplasia risk prediction tool tailored for neonates born in resource-limited settings

PURPOSE

Predicting bronchopulmonary dysplasia (BPD) to assess the risk-benefit of therapy is necessary considering the side effects of medications. We developed and validated an instrument for predicting BPD and compared it with an instrument currently used for neonates born in a Brazilian hospital.

METHODS

This was a retrospective cohort study of patients born between 2016 and 2020 with a gestational age (GA) between 23 and 30 weeks. Predictive equations were elaborated using methods of component variable selection collected on the 14th day of life; 70% of the sample was randomly selected for the construction of risk prediction equations and the remaining 30% for their validation, application, and comparison with the National Institute of Child Health and Human Development (NICHD) instrument. The sensitivity, specificity, and predictive values of the equations were calculated.

RESULTS

The equation that used variables with p < 5% in Fisher's exact test presented the best results: specificity of 98% and positive predictive value of 93% and could be used for BPD prediction of all small-for-gestational-age (SGA) infants. The NICHD calculator applied to our population had a specificity of 93% and a positive predictive value of 75% and could not be applied to extremely SGA infants.

CONCLUSION

Our tool can predict the risk of BPD on the 14th day of life, has higher specificity and positive predictive value to our population than the NICHD instrument, and can be suitable for SGA infants. The results must be confirmed by applying it to other populations to validate our tool.

Current Status and Associated Factors of Post-Hemorrhagic Hydrocephalus in Infants of 22 to 28 Weeks Gestation With Severe Intraventricular Hemorrhage in Korea: A Nationwide Cohort Study

BACKGROUND

Post-hemorrhagic hydrocephalus (PHH), a common complication of severe intraventricular hemorrhage (IVH) in very low birth weight (BW) infants, is associated with significant morbidity and poor neurological outcomes. The objective of this study was to assess the current status of PHH and analyze the risk factors associated with the necessity of treatment for PHH in infants born between 22 and 28 weeks of gestation, specifically those with severe IVH (grade 3 or 4).

METHODS

The analysis was conducted on 1,097 infants who were born between 22-28 gestational weeks and diagnosed with severe IVH, using data from the Korean Neonatal Network. We observed that the prevalence of PHH requiring treatment was 46.3% in infants with severe IVH.

RESULTS

Higher rates of mortality, transfer during admission, cerebral palsy, and ventriculoperitoneal shunt after discharge were higher in infants with PHH than in those without PHH. PHH in severe IVH was associated with a higher rate of pulmonary hemorrhage, seizures, and IVH grade 4 in the entire cohort. In addition, it was associated with a lower rate of small for gestational age and chorioamnionitis. In the subgroup analysis, high BW, outborn status, pulmonary hemorrhage, seizure, sepsis, and IVH grade 4 were associated with a higher incidence of PHH between 22 and 25 gestational weeks (GW). In infants born between 26 and 28 GW, a higher incidence of PHH was associated with seizures and IVH grade 4.

CONCLUSION

It is necessary to maintain meticulous monitoring and neurological intervention for infants with PHH not only during admission but also after discharge. In addition, identifying the clinical factors that increase the likelihood of developing PHH from severe IVH is crucial.

Paediatric intensive care admissions of preterm children born <32 weeks gestation: a national retrospective cohort study using data linkage

OBJECTIVE

Survival of babies born very preterm (<32 weeks gestational age) has increased, although preterm-born children may have ongoing morbidity. We aimed to investigate the risk of admission to paediatric intensive care units (PICUs) of children born very preterm following discharge home from neonatal care.

DESIGN

Retrospective cohort study, using data linkage of National Neonatal Research Database and the Paediatric Intensive Care Audit Network datasets.

SETTING

All neonatal units and PICUs in England and Wales.

PATIENTS

Children born very preterm between 1 January 2013 and 31 December 2018 and admitted to neonatal units.

MAIN OUTCOME MEASURES

Admission to PICU after discharge home from neonatal care, before 2 years of age.

RESULTS

Of the 40 690 children discharged home from neonatal care, there were 2308 children (5.7%) with at least one admission to PICU after discharge. Of these children, there were 1901 whose first PICU admission after discharge was unplanned.The percentage of children with unplanned PICU admission varied by gestation, from 10.2% of children born <24 weeks to 3.3% born at 31 weeks.Following adjustment, unplanned PICU admission was associated with lower gestation, male sex (adjusted OR (aOR) 0.79), bronchopulmonary dysplasia (aOR 1.37), necrotising enterocolitis requiring surgery (aOR 1.39) and brain injury (aOR 1.42). For each week of increased gestation, the aOR was 0.90.

CONCLUSIONS

Most babies born <32 weeks and discharged home from neonatal care do not require PICU admission in the first 2 years. The odds of unplanned admissions to PICU were greater in the most preterm and those with significant neonatal morbidity.

Proactive Diagnosis and Tailor-Made Treatment of Patent Ductus Arteriosus in Very Preterm Infants with Routine Echocardiography in Japan: A post hoc Analysis of the PLASE Study

INTRODUCTION

A feature of the management of extremely preterm infants in Japan is proactive circulatory management using early routine echocardiography performed by neonatologists.

METHODS

This study was a post hoc analysis of the Patent ductus arteriosus and Left Atrial Size Evaluation in preterm infants (PLASE) study, which is a prospective cohort study including preterm infants admitted to 34 tertiary neonatal intensive care units in Japan between October 2015 and December 2016. We described the details of the treatment strategy of patent ductus arteriosus (PDA) based on early routine echocardiography.

RESULTS

In total, 613 preterm infants were included into the analysis. Twenty percent of infants with prophylactic indomethacin were switched to therapeutic cyclooxygenase inhibitor (COX-I) before the completion of the full prophylactic indomethacin course. Therapeutic COX-I was mostly administered based on echocardiographic findings before PDA became symptomatic or hemodynamically significant. Therapeutic COX-I was frequently discontinued after one or two doses before the full course (three doses) was completed. The proportion of infants requiring additional treatment (additional therapeutic COX-I course or surgical PDA closure) after discontinued COX-I courses (<3 doses) compared to infants after completed 3 doses course was significantly lower (after the first therapeutic COX-I course 46% vs. 68%, p < 0.001) or without a significant difference (after the second or third course).

CONCLUSIONS

The clinical management of PDA in Japan featured (1) COX-I administration based on echocardiographic findings before symptomatic or hemodynamically significant PDA appeared and (2) frequent discontinuation of therapeutic COX-I before completing the standard three doses course.

Incidence of histologic chorioamnionitis in a rural community hospital

BACKGROUND

Histological chorioamnionitis (HCA) is a pathological condition defined as an acute inflammation of the amniochorionic membranes which has been linked to a wide range of adverse neonatal events.

AIM

The purpose of this study is to identify the incidence of HCA in the rural population and evaluate whether there are significant differences in these incidences within the different clinical parameters of delivery method, gravidity, gestational age, previous cesarean section, reason for cesarean section and body mass index (BMI).

METHODS

A retrospective chart review was conducted on 462 consecutive deliveries that occurred in a rural hospital during a four-year period. Data collected was analyzed using independent sample T-tests, chi-squared tests, and descriptive statistics, with a p-value of < 0.05.

RESULTS

Overall incidence of HCA was 15.9% (73/459), with a term incidence of 16.2% (68/421) and preterm incidence of 13.2% (5/38). The incidence of HCA was significantly higher in vaginal deliveries (18.8%; n = 54/288) than C-section deliveries (11.1%; n = 19/171) (p = 0.03). Incidence of clinical chorioamnionitis was 0.43% (2/462), with 2.74% (2/73) of HCA manifesting clinically.

CONCLUSIONS

Evaluation of the incidence of HCA and associated clinical parameters in this study showed a marked decrease in the incidence of HCA when compared to other studies. Strategies to reduce the incidence of HCA include reducing the length of labor via active labor management. We hypothesize that these findings are due to the consistent use of active labor management and our rural study population, but further investigation is required to confirm this.

Adrenal volumes in fetuses delivering prior to 32 weeks' gestation: An MRI pilot study

INTRODUCTION

Spontaneous preterm birth prior to 32 weeks' gestation accounts for 1% of all deliveries and is associated with high rates of morbidity and mortality. A total of 70% are associated with chorioamnionitis which increases the incidence of morbidity, but for which there is no noninvasive antenatal test. Fetal adrenal glands produce cortisol and dehydroepiandosterone-sulphate which upregulate prior to spontaneous preterm birth. Ultrasound suggests that adrenal volumes may increase prior to preterm birth, but studies are limited. This study aimed to: (i) demonstrate reproducibility of magnetic resonance imaging (MRI) derived adrenal volumetry; (ii) derive normal ranges of total adrenal volumes, and adrenal: body volume for normal; (iii) compare with those who have spontaneous very preterm birth; and (iv) correlate with histopathological chorioamnionitis.

MATERIAL AND METHODS

Patients at high risk of preterm birth prior to 32 weeks were prospectively recruited, and included if they did deliver prior to 32 weeks; a control group who delivered an uncomplicated pregnancy at term was also recruited. T2 weighted images of the entire uterus were obtained, and a deformable slice-to-volume method was used to reconstruct the fetal abdomen. Adrenal and body volumes were obtained via manual segmentation, and adrenal: body volume ratios generated. Normal ranges were created using control data. Differences between groups were investigated accounting for the effect of gestation by use of regression analysis. Placental histopathology was reviewed for pregnancies delivering preterm.

RESULTS

A total of 56 controls and 26 cases were included in the analysis. Volumetry was consistent between observers. Adrenal volumes were not higher in the case group (p = 0.2); adrenal: body volume ratios were higher (p = 0.011), persisting in the presence of chorioamnionitis (p = 0.017). A cluster of three pairs of adrenal glands below the fifth centile were noted among the cases all of whom had a protracted period at risk of preterm birth prior to MRI.

CONCLUSIONS

Adrenal: body volume ratios are significantly larger in fetuses who go on to deliver preterm than those delivering at term. Adrenal volumes were not significantly larger, we hypothesize that this could be due to an adrenal atrophy in fetuses with fulminating chorioamnionitis. A straightforward relationship of adrenal size being increased prior to preterm birth should not be assumed.

Gastrointestinal perforation in extremely low birth weight infants: A single center retrospective study in China

BACKGROUND

Gastrointestinal perforation in extremely low birth weight infants, characterized by its rapid onset, multiple complications, and critical condition, poses a significant risk of infant mortality. The aim of this study was to investigate the clinical characteristics of pneumoperitoneum in extremely low birth weight infants (ELBWI) and explore the risk factors associated with gastrointestinal perforation in very low birth weight preterm infants. Additionally, we shared our surgical experiences in managing gastrointestinal perforation among extremely low birth weight infants.

METHODS

The Department of Neonatology at Chengdu Women and Children's Central Hospital conducted a retrospective study on gastrointestinal perforation in extremely low birth weight infants (birth weight <1000 g) who were admitted between 2014 and 2021. After baseline analysis and comparing it with the control group, we identified the risk factors associated with gastrointestinal perforation in ELBWI by multiple logistic regression analysis. The Kaplan-Meier analysis was performed to assess the adverse effect of gastrointestinal perforation for survival in ELBW infants. Cox multivariate regression analysis was used to evaluate hazard level of different variables for ELBW infants survival.

RESULTS

Hemodynamically significant patent ductus arteriosus (hsPDA)(p = 0.043, OR = 2.779) and sepsis (p = 0.014, OR = 2.265) were significant risk factors for gastrointestinal perforation in extremely low birth weight infants. The Cox proportional hazard model revealed that intraventricular hemorrhage (HR = 2.854, p＜0.001) Sepsis (HR = 1.645, p = 0.015) and gastrointestinal perforation (HR = 1.876, p = 0.008) had detrimental effects on the survival of extremely low birth weight infants; conversely, ibuprofen (HR = 0.304, p＜0.001) and blood transfusion (HR = 0.372, p＜0.001) are beneficial factors for their survival. The preoperative indicators of infection in infants with spontaneous intestinal perforation (SIP) were significantly better than those in the necrotizing enterocolitis (NEC) group (p < 0.05).

CONCLUSIONS

Gastrointestinal perforation poses a significant threat the survival of extremely low birth weight (ELBW) infants, with hsPDA and sepsis serving as predisposing factors for gastrointestinal perforation. The gastrointestinal perforation caused by various diseases exhibits distinct clinical characteristics, necessitating tailored surgical approaches based on operative conditions.

Association between Preconception Dietary Fiber Intake and Preterm Birth: The Japan Environment and Children's Study

Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality. Therefore, this study aimed to determine whether preconception dietary fiber intake is associated with PTB. This was a prospective cohort Japan Environmental and Children's Study (JECS). The study population comprised 85,116 singleton live-birth pregnancies from the JECS database delivered between 2011 and 2014. The participants were categorized into five groups based on their preconception dietary fiber intake quintiles (Q1 and Q5 were the lowest and highest groups, respectively). Multiple logistic regression analysis was performed to determine the association between preconception dietary fiber intake and PTB. Multiple logistic regression analysis revealed that the risk for PTB before 34 weeks was lower in the Q3, Q4, and Q5 groups than in the Q1 group (Q3: adjusted odds ratio [aOR] 0.78, 95% confidence interval [CI] 0.62-0.997; Q4: aOR 0.74, 95% CI 0.57-0.95; Q5: aOR 0.68, 95% CI 0.50-0.92). However, there was no significant difference between preconception dietary fiber intake and PTB before 37 weeks. In conclusion, higher preconception dietary fiber intake correlated with a reduced the risk for PTB before 34 weeks. Therefore, new recommendations on dietary fiber intake as part of preconception care should be considered.

Identifying Newborns with Hypoxic-Ischemic Encephalopathy in Hospital Discharge Data: A Validation Study

Hospital discharge databases (HDDs) are increasingly used for research on health of newborns. Linkage between a French population-based cohort of newborns with hypoxic-ischemic encephalopathy (HIE) and national HDD showed that the HIE ICD-10 code was not accurately reported. Our results suggest that HDD should not be used for research on neonatal HIE without prior validation of HIE ICD-10 codes.

Outcome in very preterm infants: a population-based study from a regional center in Austria

Aim

To determine short-term morbidity and mortality rates in the first state-wide Austrian neonatal cohort and comparison to (inter)national data.

Methods

Observational, population-based cohort study, analyzing data of preterm infants (<32 + 0 weeks of gestation) born between 2007 and 2020 (n = 501) in an Austrian state who were admitted to the neonatal intensive care unit. Outcome criteria were mortality, neonatal morbidities: bronchopulmonary dysplasia (BPD), severe necrotizing enterocolitis (NEC), severe intraventricular hemorrhage (IVH grades III-IV), severe retinopathy of prematurity (ROP grades III-V) and survival-free of major complications.

Results

Overall survival rate was 95%, survival free of major complications was 79%. Prevalence for BPD was 11.2%, surgical NEC 4.0%, severe IVH 4.6%, and for severe ROP 2.6%, respectively. In the extremely low gestational age neonates (ELGAN) born <28 weeks of gestation (n = 158), survival was 88% and survival free of major complications 58.8%. Over time, mortality decreased significantly, predominantly driven by the improvement of infants born <28 week of gestation and survival free of major complications improved.

Conclusions

This study demonstrates a very low mortality rate that decreases over time. Short-term morbidities and survival free of major complications do not differ from (inter)national data in a similar group of very preterm infants. Standard operating procedures, simulation trainings and accordance to international trials may improve patient care and surpass center case loads.

A Survey of the Union of European Neonatal and Perinatal Societies on Neonatal Respiratory Care in Neonatal Intensive Care Units

(1) Background: Our survey aimed to gather information on respiratory care in Neonatal Intensive Care Units (NICUs) in the European and Mediterranean region. (2) Methods: Cross-sectional electronic survey. An 89-item questionnaire focusing on the current modes, devices, and strategies employed in neonatal units in the domain of respiratory care was sent to directors/heads of 528 NICUs. The adherence to the "European consensus guidelines on the management of respiratory distress syndrome" was assessed for comparison. (3) Results: The response rate was 75% (397/528 units). In most Delivery Rooms (DRs), full resuscitation is given from 22 to 23 weeks gestational age. A T-piece device with facial masks or short binasal prongs are commonly used for respiratory stabilization. Initial FiO2 is set as per guidelines. Most units use heated humidified gases to prevent heat loss. SpO2 and ECG monitoring are largely performed. Surfactant in the DR is preferentially given through Intubation-Surfactant-Extubation (INSURE) or Less-Invasive-Surfactant-Administration (LISA) techniques. DR caffeine is widespread. In the NICUs, most of the non-invasive modes used are nasal CPAP and nasal intermittent positive-pressure ventilation. Volume-targeted, synchronized intermittent positive-pressure ventilation is the preferred invasive mode to treat acute respiratory distress. Pulmonary recruitment maneuvers are common approaches. During NICU stay, surfactant administration is primarily guided by FiO2 and SpO2/FiO2 ratio, and it is mostly performed through LISA or INSURE. Steroids are used to facilitate extubation and prevent bronchopulmonary dysplasia. (4) Conclusions: Overall, clinical practices are in line with the 2022 European Guidelines, but there are some divergences. These data will allow stakeholders to make comparisons and to identify opportunities for improvement.

Variations in neonatal mortality of preterm infants with intraparenchymal haemorrhage in Europe: the EPICE cohort

OBJECTIVE

The aim of this study was to investigate variations in mortality before neonatal intensive care unit (NICU) discharge of infants born preterm with intraparenchymal haemorrhage (IPH) in Europe with a special interest for withdrawing life-sustaining therapy (WLST).

DESIGN

Secondary analysis of the Effective Perinatal Intensive Care in Europe (EPICE) cohort, 2011-2012.

SETTING

Nineteen regions in 11 European countries.

PATIENTS

All infants born between 24+0 and 31+6 weeks' gestational age (GA) with a diagnosis of IPH.

MAIN OUTCOME MEASURES

Mortality rate with multivariable analysis after adjustment for GA, antenatal steroids and gender. WLST policies were described among NICUs and within countries.

RESULTS

Among 6828 infants born alive between 24+0 and 31+6 weeks' GA and without congenital anomalies admitted to NICUs, IPH was diagnosed in 234 infants (3.4%, 95% CI 3.3% to 3.9%) and 138 of them (59%) died. The median age at death was 6 days (3-13). Mortality rates varied significantly between countries (extremes: 30%-81%; p<0.004) and most infants (69%) died after WLST. After adjustment and with reference to the UK, mortality rates were significantly higher for France, Denmark and the Netherlands, with ORs of 8.8 (95% CI 3.3 to 23.6), 5.9 (95% CI 1.6 to 21.4) and 4.8 (95% CI 1.1 to 8.9). There were variations in WLST between European regions and countries.

CONCLUSION

In infants with IPH, rates of death before discharge and death after WLST varied between European countries. These variations in mortality impede studying reliable outcomes in infants with IPH across European countries and encourage reflection of clinical practices of WLST across European units.

Factors associated with the increased incidence of necrotising enterocolitis in extremely preterm infants in Sweden between two population-based national cohorts (2004-2007 vs 2014-2016)

OBJECTIVE

To investigate potential risk factors behind the increased incidence of necrotising enterocolitis (NEC) in Swedish extremely preterm infants.

DESIGN

Registry data from two population-based national cohorts were studied. NEC diagnoses (Bell stage ≥II) were validated against hospital records.

PATIENTS

All liveborn infants <27 weeks of gestation 2004-2007 (n=704) and 2014-2016 (n=895) in Sweden.

MAIN OUTCOME MEASURES

NEC incidence.

RESULTS

The validation process resulted in a 28% reduction of NEC cases but still confirmed a higher NEC incidence in the later epoch compared with the earlier (73/895 (8.2%) vs 27/704 (3.8%), p=0.001), while the composite of NEC or death was lower (244/895 (27.3%) vs 229/704 (32.5%), p=0.022). In a multivariable Cox regression model, censored for mortality, there was no significant difference in early NEC (0-7 days of life) between epochs (HR=0.9 (95% CI 0.5 to 1.9), p=0.9), but being born in the later epoch remained an independent risk factor for late NEC (>7 days) (HR=2.7 (95% CI 1.5 to 5.0), p=0.001). In propensity score analysis, a significant epoch difference in NEC incidence (12% vs 2.8%, p<0.001) was observed only in the tertile of infants at highest risk of NEC, where the 28-day mortality was lower in the later epoch (35% vs 50%, p=0.001). More NEC cases were diagnosed with intramural gas in the later epoch (33/73 (45.2%) vs 6/26 (23.1%), p=0.047).

CONCLUSIONS

The increase in NEC incidence between epochs was limited to cases occurring after 7 days of life and was partly explained by increased survival in the most extremely preterm infants. Misclassification of NEC is common.

Short-term prognosis of very-preterm infants of ethnic minorities and Han nationality at high altitude: a single-center, retrospective study

OBJECTIVE

We aimed to analyze the perinatal care of very-preterm infants (VPIs) in plateau areas of China and to explore any differences in short-term outcomes between ethnic minorities and Han nationality.

METHODS

VPIs with gestational age (GA) <32 weeks admitted to Qinghai Red Cross Hospital from 1 January 2018 to 31 December 2020 were enrolled. Maternal information, neonatal information, perinatal care and discharge outcomes were retrospectively collected and analyzed.

RESULTS

A total of 302 VPIs were examined, including 143 (47.4%) ethnic minority infants and 159 (52.6%) Han infants. Mothers of ethnic minority infants were significantly younger than those of Han infants (27 y vs. 30 y, p < .001). There were no differences in the incidence of assisted reproduction, multiple pregnancies, maternal hypertension, clinical chorioamnionitis or premature rupture of membranes >18 h between ethnic minority mothers and Han mothers. Lower proportions of cesarean section and incidence of maternal diabetes were observed in ethnic minority mothers than in Han mothers [(9.1 vs.17.6%, p < .05) and (42.7 vs. 57.9%, p < .05, respectively)]. Meanwhile, fewer antenatal steroids were used in minority group than Han group (65.7 vs. 81.1%, p < .05). No significant differences in rates of death, active treatment, necrotizing enterocolitis stage ≥2, moderate-to-severe BPD, and incidence of severe retinopathy of prematurity in VPIs were found between the two groups and in all GA subgroups. Severe neurological injury was significantly less common in the minority newborns than in the Han infants (1.2 vs. 6.1%, p < .05). Compared with Han group, no excess risk of death, death or major morbidity, death despite active treatment, death or major morbidity despite active treatment was observed in ethnic minorities, with or without adjusting for gestational age and prenatal steroids.

CONCLUSIONS

Short-term prognosis of VPIs of ethnic minorities were similar to those of Han nationality.

Management of bronchopulmonary dysplasia in Japan: A nationwide survey

BACKGROUND

The incidence of bronchopulmonary dysplasia (BPD) and respiratory management practices for extremely low birth weight infants (ELBWIs) widely vary among institutions and countries.

AIMS

To clarify the variation and characteristics of the current practices of Japanese neonatologists managing patients with BPD.

STUDY DESIGN

Questionnaire-based survey.

PARTICIPANTS

Level II and III perinatal centers certified by the Japan Society of Perinatal and Neonatal Medicine.

OUTCOME MEASURES

Policies of the neonatal intensive care units (NICUs) regarding respiratory care and medications for BPD prevention and treatment.

RESULTS

A total of 76 % of facilities (207/274) responded to our survey. The response rates of level III and II facilities were 91 % (102/112) and 35 % (105/296), respectively. INtubation-SURfactant-Extubation and Less Invasive Surfactant Administration methods were performed in 23 % (47/206) and 1 % (3/206) of facilities, respectively. For the prophylactic purpose, systemic and inhaled steroids were administered "frequently" or "occasionally" in 14 % (28/205) and 42 % (86/204) of NICUs, respectively. For the therapeutic purpose, systemic and inhaled steroids were administered "frequently" or "occasionally" in 84 % (171/204) and 29 % (59/204) of NICUs, respectively. Approximately half of the NICUs (99/202) used volume-targeted ventilation (VTV) "frequently" or "occasionally" in progressing BPD. High-frequency oscillation ventilation (HFOV) was used for progressing BPD "frequently" and "occasionally" in 89 % (180/202) of the facilities.

CONCLUSIONS

Our study provided an overview and characteristics of BPD management in Japan in recent years. Noninvasive approaches with surfactant administration remain not widely used in Japan. HFOV is a widely accepted management for progressing BPD.

Remote Monitoring for Seizures During Therapeutic Hypothermia in Neonates With Hypoxic-Ischemic Encephalopathy

Importance

Neonates with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH) frequently experience seizures, which are associated with adverse outcomes. Efforts to rapidly identify seizures and reduce seizure burden may positively change neurologic and neurodevelopmental outcomes.

Objective

To describe the onset, treatment, and evolution of seizures in a large cohort of newborns with HIE during TH assisted by a telehealth model and remote neuromonitoring approach.

Design, Setting, and Participants

This was a prospective, observational, multicenter cohort study performed between July 2017 and December 2021 in 32 hospitals in Brazil. Participants were newborns with HIE meeting eligibility criteria and receiving TH. Data were analyzed from November 2022 to April 2023.

Exposure

Infants with HIE receiving TH were remotely monitored with 3-channel amplitude-integrated electroencephalography (aEEG) including raw tracing and video imaging, and bedside clinicians received assistance from trained neonatologists and neurologists.

Main Outcomes and Measures

Data on modified Sarnat examination, presence, timing and seizure type, aEEG background activity, sleep-wake cycling, and antiepileptic drugs used were collected. Descriptive statistical analysis was used with independent t test, χ2, Mann-Whitney test, and post hoc analyses applied for associations.

Results

A total of 872 cooled newborns were enrolled; the median (IQR) gestational age was 39 (38-40) weeks, 518 (59.4%) were male, and 59 (6.8%) were classified as having mild encephalopathy by modified Sarnat examination, 504 (57.8%) as moderate, and 180 (20.6%) as severe. Electrographic seizures were identified in 296 newborns (33.9%), being only electrographic in 213 (71.9%) and clinical followed by electroclinical uncoupling in 50 (16.9%). Early abnormal background activity had a significant association with seizures. Infants with flat trace had the highest rate of seizures (58 infants [68.2%]) and the greatest association with the incidence of seizures (odds ratio [OR], 12.90; 95% CI, 7.57-22.22) compared with continuous normal voltage. The absence of sleep-wake cycling was also associated with a higher occurrence of seizures (OR, 2.22; 95% CI, 1.67-2.96). Seizure onset was most frequent between 6 and 24 hours of life (181 infants [61.1%]); however, seizure occurred in 34 infants (11.5%) during rewarming. A single antiepileptic drug controlled seizures in 192 infants (64.9%). The first line antiepileptic drug was phenobarbital in 294 (99.3%).

Conclusions and Relevance

In this cohort study of newborns with HIE treated with TH, electrographic seizure activity occurred in 296 infants (33.9%) and was predominantly electrographic. Seizure control was obtained with a single antiepileptic drug in 192 infants (64.9%). These findings suggest neonatal neurocritical care can be delivered at remote limited resource hospitals due to innovations in technology and telehealth.

The Impact of Intraventricular Hemorrhage and Periventricular Leukomalacia on Mortality and Neurodevelopmental Outcome in Very Preterm and Very Low Birthweight Infants: A Prospective Population-based Cohort Study

OBJECTIVE

To survey the incidence of intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL) by gestational age and to report the impact on mortality and neurodevelopmental outcome in very preterm/very low birthweight infants.

STUDY DESIGN

This was a population-based cohort study of 1927 very preterm/very low birthweight infants born in 2014-2016 and admitted to Flemish neonatal intensive care units. Infants underwent standard follow-up assessment until 2 years corrected age with the Bayley Scales of Infant and Toddler Development and neurological assessments.

RESULTS

No brain lesion was present in 31% of infants born at <26 weeks of gestation and 75.8% in infants born at 29-32 weeks of gestation. The prevalence of low-grade IVH/PVL (grades I and II) was 16.8% and 12.7%, respectively. Low-grade IVH/PVL was not related significantly to an increased likelihood of mortality, motor delay, or cognitive delay, except for PVL grade II, which was associated with a 4-fold increase in developing cerebral palsy (OR, 4.1; 95% CI, 1.2-14.6). High-grade lesions (III-IV) were present in 22.0% of the infants born at <26 weeks of gestational and 3.1% at 29-32 weeks of gestation, and the odds of death were ≥14.0 (IVH: OR, 14.0; 95% CI, 9.0-21.9; PVL: OR, 14.1; 95% CI, 6.6-29.9). PVL grades III-IV showed an increased odds of 17.2 for motor delay and 12.3 for cerebral palsy, but were not found to be associated significantly with cognitive delay (OR, 2.9; 95% CI, 0.5-17.5; P = .24).

CONCLUSIONS

Both the prevalence and severity of IVH/PVL decreased significantly with advancing gestational age. More than 75% of all infants with low grades of IVH/PVL showed normal motor and cognitive outcome at 2 years corrected age. High-grade PVL/IVH has become less common and is associated with adverse outcomes.

Microbial signatures in amniotic fluid at preterm birth and association with bronchopulmonary dysplasia

BACKGROUND

Microbiome dysbiosis can have long-lasting effects on our health and induce the development of various diseases. Bronchopulmonary dysplasia (BPD) is a multifactorial disease with pre- and postnatal origins including intra-amniotic infection as main risk factor. Recently, postnatal pathologic lung microbiota colonization was associated with BPD. The objectives of this prospective observational cohort study were to describe differences in bacterial signatures in the amniotic fluid (AF) of intact pregnancies without clinical signs or risk of preterm delivery and AF samples obtained during preterm deliveries and their variations between different BPD disease severity stages.

METHODS

AF samples were collected under sterile conditions during fetal intervention from intact pregnancies (n = 17) or immediately before preterm delivery < 32 weeks (n = 126). Metabarcoding based approaches were used for the molecular assessment of bacterial 16S rRNA genes to describe bacterial community structure.

RESULTS

The absolute amount of 16S rRNA genes was significantly increased in AF of preterm deliveries and detailed profiling revealed a reduced alpha diversity and a significant change in beta diversity with a reduced relative abundance of 16S rRNA genes indicative for Lactobacillus and Acetobacter while Fusobacterium, Pseudomonas, Ureaplasma and Staphylococcus 16S rRNA gene prevailed. Although classification of BPD by disease severity revealed equivalent absolute 16S rRNA gene abundance and alpha and beta diversity in no, mild and moderate/severe BPD groups, for some 16S rRNA genes differences were observed in AF samples. Bacterial signatures of infants with moderate/severe BPD showed predominance of 16S rRNA genes belonging to the Escherichia-Shigella cluster while Ureaplasma and Enterococcus species were enriched in AF samples of infants with mild BPD.

CONCLUSIONS

Our study identified distinct and diverse intrauterine 16S rRNA gene patterns in preterm infants immediately before birth, differing from the 16S rRNA gene signature of intact pregnancies. The distinct 16S rRNA gene signatures at birth derive from bacteria with varying pathogenicity to the immature lung and are suited to identify preterm infants at risk. Our results emphasize the prenatal impact to the origins of BPD.

Delivery room intubation and severe intraventricular hemorrhage in extremely preterm infants without low Apgar scores: A Japanese retrospective cohort study

The purpose of this study was to assess the associations between delivery room intubation (DRI) and severe intraventricular hemorrhage (IVH), as well as other neonatal outcomes, among extremely preterm infants without low Apgar scores using data from a large-scale neonatal registry data in Japan. We analyzed data for infants born at 24-27 gestational weeks between 2003 and 2019 in Japan using robust Poisson regression. Infants with low Apgar scores (≤ 1 at 1 min or ≤ 3 at 5 min) were excluded. The primary outcome was severe IVH. Secondary outcomes were other neonatal morbidities and mortality. The full cohort included 16,081 infants (intubation cohort, 13,367; no intubation cohort, 2714). The rate of DRI increased over time (78.6%, 2003-2008; 83.4%, 2009-2014; 87.8%, 2015-2019), while the rate of severe IVH decreased (7.1%, 2003-2008; 5.7%, 2009-2014; 5.3%, 2015-2019). Infants with DRI had a higher risk of severe IVH than those without DRI (6.8% vs. 2.3%; adjusted risk ratio, 1.86; 95% confidence interval, 1.33-2.58). The results did not change substantially when stratified by gestational age. Despite conflicting changes over time in DRI and severe IVH, DRI was associated with an increased risk of severe IVH among extremely preterm infants in Japan.

Heterogeneity and Gaps in Reporting Primary Outcomes From Neonatal Trials

OBJECTIVES

Clear outcome reporting in clinical trials facilitates accurate interpretation and application of findings and improves evidence-informed decision-making. Standardized core outcomes for reporting neonatal trials have been developed, but little is known about how primary outcomes are reported in neonatal trials. Our aim was to identify strengths and weaknesses of primary outcome reporting in recent neonatal trials.

METHODS

Neonatal trials including ≥100 participants/arm published between 2015 and 2020 with at least 1 primary outcome from a neonatal core outcome set were eligible. Raters recruited from Cochrane Neonatal were trained to evaluate the trials' primary outcome reporting completeness using relevant items from Consolidated Standards of Reporting Trials 2010 and Consolidated Standards of Reporting Trials-Outcomes 2022 pertaining to the reporting of the definition, selection, measurement, analysis, and interpretation of primary trial outcomes. All trial reports were assessed by 3 raters. Assessments and discrepancies between raters were analyzed.

RESULTS

Outcome-reporting evaluations were completed for 36 included neonatal trials by 39 raters. Levels of outcome reporting completeness were highly variable. All trials fully reported the primary outcome measurement domain, statistical methods used to compare treatment groups, and participant flow. Yet, only 28% of trials fully reported on minimal important difference, 24% on outcome data missingness, 66% on blinding of the outcome assessor, and 42% on handling of outcome multiplicity.

CONCLUSIONS

Primary outcome reporting in neonatal trials often lacks key information needed for interpretability of results, knowledge synthesis, and evidence-informed decision-making in neonatology. Use of existing outcome-reporting guidelines by trialists, journals, and peer reviewers will enhance transparent reporting of neonatal trials.

Outcomes of congenital diaphragmatic hernia among preterm infants: inverse probability of treatment weighting analysis

OBJECTIVES

To evaluate the survival and intact-survival rates among preterm infants with congenital diaphragm hernia (CDH).

STUDY DESIGN

Multicenter retrospective cohort study of 849 infants born between 2006 and 2020 at 15 Japanese CDH study group facilities. Multivariate logistic regression analysis adjusted using inverse probability treatment weighting (IPTW) method was used. We also compare trends of intact-survival rates among term and preterm infants with CDH.

RESULTS

After adjusting using the IPTW method for CDH severity, sex, APGAR score at 5 min, and cesarean delivery, gestational age and survival rates have a significantly positive correlation [coefficient of determination (COEF) 3.40, 95% confidence interval (CI), 1.58-5.21, p value <0.001] and higher intact-survival rate [COEF 2.39, 95% CI, 1.73-4.06, p value 0.005]. Trends of intact-survival rates for both preterm and term infants had significantly changed, but improvement in preterm infants was much smaller than in term infants.

CONCLUSION

Prematurity was a significant risk factor for survival and intact-survival among infants with CDH, regardless of adjustment for CDH severity.

Decision-making for extremely preterm infants with severe hemorrhages on head ultrasound: Science, values, and communication skills

Severe intracranial hemorrhages are not rare in extremely preterm infants. They occur early, generally when babies require life-sustaining interventions. This may lead to ethical discussions and decision-making about levels of care. Prognosis is variable and depends on the extent, location, and laterality of the lesions, and, importantly also on the subsequent occurrence of other clinical complications or progressive ventricular dilatation. Decision-making should depend on prognosis and parental values. This article will review prognosis and the uncertainty of outcomes for different lesions and provide an outline of ways to conduct an ethically appropriate discussion on the decision of whether to continue life sustaining therapy. It is possible to communicate in a compassionate and honest way with parents and engage in decision-making, focussing on personalized information and decisions, and on function, as opposed to diagnosis.

Trends, Characteristic, and Outcomes of Preterm Infants Who Received Postnatal Corticosteroid: A Cohort Study from 7 High-Income Countries

INTRODUCTION

Our objective was to evaluate the temporal trend of systemic postnatal steroid (PNS) receipt in infants of 24-28 weeks' gestational age, identify characteristics associated with PNS receipt, and correlate PNS receipt with the incidence of bronchopulmonary dysplasia (BPD) and BPD/death from an international cohort included in the iNeo network.

METHODS

We conducted a retrospective study using data from 2010 to 2018 from seven international networks participating in iNeo (Canada, Finland, Israel, Japan, Spain, Sweden, and Switzerland). Neonates of 24 and 28 weeks' gestational age who survived 7 days and who received PNS were included. We assessed temporal trend of rates of systemic PNS receipt and BPD/death.

RESULTS

A total of 47,401 neonates were included. The mean (SD) gestational age was 26.4 (1.3) weeks and birth weight was 915 (238) g. The PNS receipt rate was 21% (12-28% across networks) and increased over the years (18% in 2010 to 26% in 2018; p < 0.01). The BPD rate was 39% (28-44% across networks) and remained unchanged over the years (35.2% in 2010 to 35.0% in 2018). Lower gestation, male sex, small for gestational age status, and presence of persistent ductus arteriosus (PDA) were associated with higher rates of PNS receipt, BPD, and BPD/death.

CONCLUSION

The use of PNS in extremely preterm neonates increased, but there was no correlation between increased use and the BPD rate. Research is needed to determine the optimal timing, dose, and indication for PNS use in preterm neonates.

Cesarean delivery was associated with low morbidity in very low birth weight infants: A retrospective cohort study

To estimate the relationship among the cesarean delivery (CD), mortality and morbidity in very low birth weight (VLBW) infants weighing less than 1500 g. This retrospective cohort study enrolled 242 VLBW infants delivered between the 24 to 31week of gestation from 2015 to 2021. We compared CD with vaginal delivery (VD). The primary outcome was a composite neonatal morbidity including bronchopulmonary dysplasia, intraventricular hemorrhage, periventricular leukomalacia, necrotizing enterocolitis, late-onset sepsis and retinopathy of prematurity. The secondary outcome included mortality within 28 days. A multivariate logistic regression was used and adjusted for birthweight, twin pregnancy and antenatal steroids intake. The overall CD rate was 80.6%. Compared with VD, a significantly lower composite neonatal morbidity was associated with CD (adjusted odds ratio, 0.33, 95% confidence interval, 0.12-0.90, P = .031). The relationship between CD and neonatal morbidity disappeared when the VLBW infants were stratified according to the gestational age. No significant difference was observed between the VD and CD cohorts regarding mortality. Compared with VD, CD was associated with a lower morbidity in VLBW infants. Further studies are required to clarify how this association is influenced by gestational age.

Active approach in delivery room and survival of infants born between 22 and 26 gestational weeks are increasing in Spain

AIM

To describe the trends in the delivery room approach and survival of extremely premature infants over the past two decades.

METHODS

Time-series analysis of infants included in the Spanish SEN1500 network from 2004 to 2019. Patients born from 22 + 0 to 26 + 6 weeks were included. The primary outcome was an active approach in the delivery room. Survival and temporal trends were also studied.

RESULTS

The study population included 8284 patients. At 22 and 23 weeks, an active approach was followed in 41.4% and 80.8%. A temporal trend toward a more active approach was observed at 23 weeks. Antenatal steroids were administered in 19.6% and 58.1% at 22 and 23 weeks. From 24 weeks, an active approach was applied in nearly all cases throughout the period, and more than 80% of patients received antenatal steroids. The rates of survival after an active approach were 8.7%, 21.6%, 40.6%, 59.9%, and 74.7% at 22, 23, 24, 25, and 26 weeks and significantly increased over the period, except for infants born at 22 weeks.

CONCLUSION

Active management and survival of infants born from 23 weeks increased over the period, but the frequency of antenatal steroid administration was lower than the intention to resuscitate.

Bronchopulmonary Dysplasia in Extremely Premature Infants: A Scoping Review for Identifying Risk Factors

BACKGROUND

Over the years, bronchopulmonary dysplasia (BPD) affects the pulmonary function of infants, resulting in chronic health burdens for infants and their families. The aim of this scoping review was to screen available evidence regarding perinatal risk factors associated with the development and severity of BPD.

METHODS

The eligibility criteria of the studies were year of publication between 2016 and 2021; setting of a developed country; English or Japanese as the study language; and randomized controlled, cohort, or case-control design. The titles and abstracts of the studies were screened by independent reviewers.

RESULTS

Of 8189 eligible studies, 3 were included for severe BPD and 26 were included for moderate BPD. The risk factors for severe BPD were male sex, iatrogenic preterm birth, maternal hypertensive disorders of pregnancy (HDP), low gestational age, small-for-gestational-age (SGA) birth weight, mechanical ventilation on day 1, and need for patent ductus arteriosus (PDA) management. The risk factors for moderate or severe BPD included male sex, premature rupture of membranes, clinical chorioamnionitis, maternal HDP, SGA birth weight, bubbly/cystic appearance on X-ray, and PDA management.

CONCLUSIONS

We identified several risk factors for BPD. We plan to confirm the validity of the new classification using the existing dataset.

Using the Neonatal Intensive Care Unit Wisely: A National Survey of Clinicians Regarding Practices for Lower-Acuity Care

OBJECTIVE

The objective of this study was to document the practices and preferences of neonatal care stakeholders regarding location and duration of care for newborns with low illness acuity.

STUDY DESIGN

We developed a survey instrument that comprised 14 questions across 2 global scenarios and 7 specific clinical conditions. The latter included apnea of prematurity, gestational age for neonatal intensive care unit admission, jaundice, neonatal opioid withdrawal, thermoregulation, and sepsis evaluation. Respondents reported their current practice and preferences for an alternative approach. We administered the survey to individuals in the membership email distribution lists of the American Academy of Pediatrics Section on Neonatal-Perinatal Medicine, the National Association of Neonatal Nurses, and the Vermont Oxford Network.

RESULTS

Of 2284 respondents, 53% believed that infants were, in general, admitted to a higher level of care than was required, and only 13% reported that the level of care was too low. Length of stay was perceived to be generally too long by 46% of respondents and too short by 21%. Across 10 specific clinical questions, there was substantial variability in current practice and up to 35% of respondents reported discordance between current and preferred practice. These respondents preferred a lower level of care in 8 of 10 scenarios.

CONCLUSIONS

A multidisciplinary sample of US clinicians reported significant variation in the level and duration of care for infants with low illness acuity. Among individuals reporting discordance between current and preferred practice, a majority believed that current management could be accomplished in a lower level of care location.

High-proportion breast milk feeding is associated with a reduction in the incidence of IVH in very preterm infants

Objective

To investigate the protective effect of high-proportion breast milk feeding (>50%) on intraventricular hemorrhage (IVH) in very preterm infants (VPIs).

Methods

This was a retrospective secondary analysis of a prospective multi-center study, which included 604 VPIs from six hospitals in eastern China between September 2019 and December 2020. The 604 VPIs were divided into two groups according to whether IVH occurred. High-proportion breast milk feeding was defined as breast milk accounting for 51-100% of the total feeding amount both within 7 days and throughout the hospitalization. The IVH grades and the rate of high-proportion breast milk feeding were analyzed. Furthermore, to explore the relationship between high-proportion breast milk feeding and IVH grading, the VPIs' general information, perinatal factors, growth, and nutritional status during hospitalization, and related complications were compared between the two groups.

Results

High-proportion breast milk feeding was reported in 63.41% of the VPIs. Furthermore, IVH grades I-II and III-IV were noted in 39.73% (240/604) and 1.66% (10/604) of the VPIs, respectively. Univariate analysis revealed that IVH occurrence in VPIs is influenced by perinatal factors, invasive respiratory therapy, high-proportion breast milk feeding, start feeding with breast milk, the cumulative amount of early parenteral nutrition, postnatal complications, physical growth, and other factors (P < 0.05). After adjustments for gestational age, birth weight, and possible influencing factors through binary logistic regression analysis, the results revealed that high-proportion breast milk feeding and and start feeding with breast milk were associated with a lower total incidence of IVH. Further stratification showed that high-proportion breast milk feeding was associated with a lower incidence of grade I-II IVH. Similarly, after adjusting for the same factors, breast milk feeding >50% in the 1st week was associated with a decreased incidence of total IVH and further stratification showed that it was associated with a lower incidence of grade I-II IVH.

Conclusion

High-proportion breast milk feeding and breast milk feeding more than 50% of total intake during the 1st week might be protective factors for IVH grade I-II in VPIs, which further verified the neuroprotective effect of breast milk. In clinical practice, the construction of breast milk banks should be strengthened, breast milk feeding should be encouraged in neonatal intensive care units, and efforts should be made to increase breast milk feeding rates to improve the outcomes of VPIs.

Autistic traits of children born very preterm assessed using Autism Diagnostic Observation Schedule, Second Edition

Preterm birth has been linked with increased incidence of autism spectrum disorder (ASD). Despite the remarkable difference in the clinical backgrounds between ASD children born preterm and term, cross-sectional studies have found no striking difference in their autistic traits. To highlight autistic traits related with preterm birth, children born very preterm (prospective birth cohort, n = 50) and term (case cohort, n = 16), who were diagnosed as "Autism" by the Autism Diagnostic Observation Schedule (ADOS), 2nd edition, were compared using the calibrated severity scores of ADOS-2 and T-scores of the Social Responsiveness Scale, 2nd edition. No significant difference was found in the calibrated severity scores between ASD children born preterm and term. There was a trend that T-scores were smaller for the preterm cohort, which did not reach a statistical significance. Even when detailed cross-sectional information was obtained using ADOS-2, no difference in autistic traits was observed between children born very preterm and term. Our findings were consistent with a previous study, which assessed the entire prospective cohort of children born very preterm and found no difference in original ADOS scores. Further studies are warranted to delineate how preterm birth affects the autistic traits and their parental perception in a large prospective cohort.

Diagnosis and management of neonatal respiratory distress syndrome in Japan: A national survey

BACKGROUND

Respiratory distress syndrome (RDS) is characterized by a lack of lung surfactant; therefore, biochemical evidence of surfactant deficiency is needed to diagnose RDS. European guidelines recommend surfactant administration when patients need fraction of inspired oxygen exceeding 0.3 on continuous positive airway pressure or intubation. We hypothesized that the European guidelines for surfactant administration were not adopted in Japan because of the lack of RDS diagnosis. This study aimed to investigate neonatologists' attitudes and practices regarding the diagnosis and management of RDS in Japan.

METHODS

A mail-based survey regarding the diagnosis and management of RDS was conducted at 111 level III or ΙV neonatal intensive care units in Japan. The questionnaire was completed by the person in charge of each unit.

RESULTS

The overall response rate for the questionnaire was 91% (101/111 centers). All respondents referred to chest radiography, and the majority (83%) of respondents referred to stable microbubble rating (SMR) for establishing the diagnosis of RDS. Surfactant administration was chiefly based on clinical conditions, chest radiography, and/or SMR. Most units in Japan do not adopt the European criteria for surfactant administration.

CONCLUSION

In Japan, chest radiography and/or SMR are commonly used for the diagnosis of RDS and as the rationale for surfactant administration. Further studies from other countries are required to establish the ideal criteria for surfactant administration.

Mortality and morbidity of extremely low birth weight infants in Japan, 2015

BACKGROUND

In Japan, the mortality rate of extremely low birth weight (ELBW) infants is notably low in comparison with other developed countries, but the prevalence of chronic lung disease (CLD) and retinopathy of prematurity (ROP) is relatively high. This study aimed to estimate the mortality and morbidity of ELBW infants born in 2015 who were admitted to neonatal intensive care units (NICUs) in Japan and to examine the factors that affected the short-term outcomes of these infants. We also compared the mortality of ELBW infants born in 2005, 2010, and 2015.

METHODS

We analyzed the mortality, morbidity, and factors related to short-term outcomes of ELBW infants, using data from 2782 infants born in 2015 and registered at NICUs in Japan.

RESULTS

The mortality rates during NICU stays were 17.0%, 12.0%, and 9.8% for ELBW infants born in 2005, 2010, and 2015, respectively. Among ELBW infants born in 2015, multiple logistic regression analysis showed that short gestational age and low birthweight Z-score contributed to the increased risk of death. Births by cesarean section and antenatal corticosteroid administration were significantly associated with a reduced risk of death. Among infants who survived, CLD was observed in 53.1% and ROP requiring treatment was observed in 30.4%.

CONCLUSIONS

Mortality in ELBW infants decreased significantly from 2005 to 2015. As CLD and ROP may affect quality of life and long-term outcomes of infants who survived, prevention strategies and management for these complications are critical issues in neonatal care in Japan.

[Influencing factors for the development and severity of bronchopulmonary dysplasia in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g]

OBJECTIVES

To study the influencing factors for the development and severity of bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g.

METHODS

A retrospective analysis was performed on the medical data of preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g who were admitted to Women and Children's Hospital Affiliated to Xiamen University from January 1, 2017 to December 31, 2021. According to oxygen dependence on day 28 after birth, they were divided into two groups: BPD (n=218) and non-BPD (n=142). According to disease severity based on oxygen concentration required at the corrected age of 36 weeks or at discharge, the infants with BPD were divided into two groups: mild BPD (n=154) and moderate/severe BPD (n=64). Indices such as perinatal data and nutritional status were compared between groups. The multivariate logistic regression analysis was used to determine the influencing factors for BPD and its severity.

RESULTS

The incidence rate and severity of BPD increased with the reduction in gestational age and birth weight (P<0.05). The multivariate logistic regression analysis showed that a long duration of invasive mechanical ventilation (OR=1.320, P<0.05), hemodynamically significant patent ductus arteriosus (OR=2.032, P<0.05), and a prolonged time to reach oral calorie goal of 110 kcal/(kg·d) (OR=1.041, P<0.05) were risk factors for BPD, while an older gestational age was a protective factor against BPD (OR=0.535, P<0.05). Early-onset sepsis (OR=2.524, P<0.05) and a prolonged time to reach oral calorie goal of 110 kcal/(kg·d) (OR=1.029, P<0.05) were risk factors for moderate/severe BPD, while a high mean weight growth velocity was a protective factor against moderate/severe BPD (OR=0.906, P<0.05).

CONCLUSIONS

The incidence rate and severity of BPD in preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g can be reduced by shortening the duration of invasive mechanical ventilation, giving early treatment of early-onset sepsis and hemodynamically significant patent ductus arteriosus, adopting active enteral nutritional strategies, and increasing mean weight growth velocity.

Changes in perinatal management and outcomes in infants born at 23 weeks of gestational age during the last decade in Spain

INTRODUCTION

The 2021-updated guidelines of the Spanish Society of Neonatology Guidelines have moved the zone of parental discretion to 23 + 0-23 + 6 weeks. The objective of this study was to describe the changes in perinatal management at this gestational age along the last decade and to determine if a more active perinatal management has contributed to improved outcomes.

METHODS

Retrospective analysis of prospectively collected data from the 23-week infants included in the Spanish SEN 1500 neonatal network during the period 2010-2019. The main study outcomes were survival at discharge and survival without major morbidity of actively managed infants. Two periods were compared: 2010-2014 (Period 1) and 2015-2019 (Period 2). NICUs were classified into low activity NICUs (less than 50 admissions of very low birth weight infants per year) and high activity NICUs (50 or more admissions).

RESULTS

A total of 381 infants were included, 182 in Period 1 and 199 in Period 2. In Period 2 an increase in the use of intrapartum magnesium sulfate (21.5% vs 39.9%, p .002), antenatal steroids (56.6% vs 69.3%, p .011) and active neonatal approach in delivery room (76.9% vs 86.9%, p .011) were observed.The clinical outcomes of the actively managed 313 infants were similar in both periods, except for less arterial hypotension in Period 2. Survival was 27.1% in Period 1 and 25% in Period 2 (p .068) and survival without major morbidity was 2.1% and 2.3% respectively (p .914). No difference was found between low and high activity NICUs.

CONCLUSION

A change to a more active intention to treat infants born at 23 weeks is taking place in Spain. But the survival rate of the actively-managed infants has remained stable around 25-30% during the study period. A multidisciplinary effort is needed to improve outcomes in this population.

Association Between Retinopathy of Prematurity in Very-Low-Birth-Weight Infants and Neurodevelopmental Impairment

PURPOSE

To evaluate the impact of retinopathy of prematurity (ROP) severity and the treatment of very-low-birth-weight infants (VLBWIs) on neurodevelopmental impairment in early childhood.

DESIGN

Prospective cohort study.

METHOD

This was a prospective cohort study. The data were obtained from the Korean Neonatal Network (KNN), a nationwide registry for VLBWIs. Infants who were born from 2013 to 2015 and underwent ROP evaluation at birth and neurodevelopmental examinations at corrected ages of 18 to 24 months were included in the study. Infants with a history of meningitis or severe congenital anomalies were excluded. The VLBWI patients were grouped into no ROP, no treatment-requiring ROP (non-TR-ROP), and treatment-requiring ROP (TR-ROP) groups. Neurodevelopmental impairment was defined as participants who had at least 1 developmental problem according to the Bayley Scales of Infant and Toddler Development-2nd Edition (Bayley-II; <70), Bayley Scales of Infant and Toddler Development-3rd Edition (Bayley-III; <70), and Korean Developmental Screening Test (K-DST) tests (below -1 SD), and the Korean Ages and Stages Questionnaire (K-ASQ) (below the threshold) and Gross Motor Function Classification System (GMFCS; at level 2 or above). Multivariable logistic regression analysis was performed to evaluate the association between ROP and neurodevelopmental impairment.

RESULT

Among 3132 infants, 1093 (34.9%) had ROP. Among the ROP infants, 644 were not treated for ROP (non-TR-ROP group) and 449 received ROP treatments (TR-ROP group). The patients in the TR-ROP group had an increased risk of developing neurodevelopmental problems compared to those in the no ROP group (odds ratio [OR] = 1.72, 95% CI = 1.33-2.21). The TR-ROP group had a higher risk of all 3 types of neurodevelopmental problems: mental (OR = 1.62, 95% CI = 1.25-2.09), social (OR = 1.62, 95% CI = 1.12-2.09), and motor (OR = 1.69, 95% CI = 1.31-2.18). The risk of neurodevelopmental problems in patients treated with laser therapy did not differ from that in patients treated with anti-vascular endothelial growth factor (anti-VEGF) therapy (OR = 1.17, 95% CI = 0.73-1.88).

CONCLUSION

ROP was independently associated with neurodevelopmental impairment in early childhood. The type of ROP treatment (anti-VEGF or laser treatment) did not affect neurodevelopmental impairment in patients in the TR-ROP group.

Mortality and Morbidity in Premature Infants: An East and West Comparative Study

OBJECTIVE

Survival of preterm infants differs dramatically depending on birthplace. No previous studies have compared outcomes of preterm infants between low middle-income and high-income countries such as India and the United States. The purpose of this study is to evaluate differences in care practices, resources, mortality, and morbidities in preterm infants with birth weight 700 to 1,500 g between two major neonatal centers in these countries.

STUDY DESIGN

This is a retrospective cohort study with de-identified data from Fernandez Hospital (FH) in Hyderabad, India, and Texas Children's Hospital (TCH) in Houston, TX, for infants born January 2016 to December 2018, and weighing 700 to 1,500 g at birth. The primary outcome was death before hospital discharge.

RESULTS

Of 1,195 infants, 736 were admitted to FH and 459 were admitted to TCH. After controlling for differences in gestational age, small for gestational age, and antenatal corticosteroid use, TCH patients had lower mortality before hospital discharge (adjusted odds ratio [aOR] = 0.28, 95% confidence interval [CI]: 0.16-0.48, p < 0.001) and more bronchopulmonary dysplasia (BPD; aOR = 2.2, 95% CI: 1.51-3.21, p < 0.001). The composite outcome of death or BPD and death or any major morbidity (BPD or intraventricular hemorrhage grade II or more or periventricular leukomalacia grade II or more or retinopathy of prematurity requiring treatment) were not different.

CONCLUSION

In this study, TCH infants had decreased odds of death before hospital discharge compared with FH but higher odds of BPD, which may be related to increased survival and differences in care practices.

KEY POINTS

· Few studies compared outcomes of premature infants between different high-income countries.. · There are no studies comparing preterm infants between low middle-income and high-income countries such as India and the United States.. · This study evaluated detailed comparison of care practices and infrastructure of NICUs in India and United states..

Epidemiology of post-hemorrhagic ventricular dilatation in very preterm infants

OBJECTIVE

To describe the incidence, trends, management's variability and short-term outcomes of preterm infants with severe post-hemorrhagic ventricular dilatation (sPHVD).

METHODS

We reviewed infants &lt;33 weeks' gestation who had PHVD and were admitted to the Canadian Neonatal Network between 2010 and 2018. We compared perinatal characteristics and short-term outcomes between those with sPHVD and those with mild/moderate PHVD and those with and without ventriculo-peritoneal (VP) shunt.

RESULTS

Of 29,417 infants, 2439 (8%) had PHVD; rate increased from 7.3% in 2010 to 9.6% in 2018 (P = 0.005). Among infants with PHVD, sPHVD (19%) and VP shunt (29%) rates varied significantly across Canadian centers and between geographic regions (P &lt; 0.01 and P = 0.0002). On multivariable analysis, sPHVD was associated with greater mortality, seizures and meningitis compared to mild/moderate PHVD.

CONCLUSIONS

Significant variability in sPHVD and VP shunt rates exists between centers and regions in Canada. sPHVD was associated with increased mortality and morbidities.

Long-term neurodevelopmental outcome in preterm infants with intraventricular haemorrhage

BACKGROUND

Intraventricular haemorrhage (IVH) is one of the key risks for long-term neurodevelopmental issues. There remains controversy over the impact low-grade IVH has on the long-term outcome of premature infants. This study describes the long-term neurodevelopmental impact of Grade I and II IVH in former preterm infants in the early school years.

METHODS

This is a retrospective cohort analysis from one tertiary neonatal intensive care unit (NICU) in Australia including all infants born at <30 weeks' gestation and admitted to the NICU between 2006 and 2013 with complete ultrasound reports and follow-up results. Results of standardised tests for neurodevelopmental outcomes at 5 and 8 years were compared between infants who suffered mild IVH and infants who had normal head ultrasounds.

RESULTS

During the study period, 491 infants <30 weeks gestation were admitted; 275 patients had full follow-up data available. We found no significant difference in examined outcomes at 5- and 8-year follow-up.

CONCLUSION

Mild IVH does not affect cognitive, motor and academic outcomes at school age.

Impact of Outborn/Inborn Birth Status of Infants Born at <29 Weeks of Gestation on Neurodevelopmental Impairment: A Nationwide Cohort Study in Korea

This study designed to evaluate the short- and long-term outcomes of outborn and inborn preterm infants enhancing the regional perinatal system in South Korea. It is a prospective cohort study of the Korean neonatal network database for infants born at <29 weeks of gestation between 2013 and 2015. Of 2995 eligible infants, 312 were outborn, and 976 completed the assessment of long-term outcome at 18-24 months of corrected age. The mean gestational age was significantly younger in outborn infants than in inborn infants (p = 0.004). The mean Apgar score at 5 min was higher in inborn infants (p = 0.046). More inborn preterm infants died before discharge (p < 0.001); however, most of the other short-term outcomes occurred significantly more often in outborn infants than in inborn infants. The outborn infants had higher odds of neurodevelopmental impairment (adjusted odds ratio (aOR) 2.412, 95% confidence interval (CI) 1.585-3.670), cerebral palsy (aOR 4.460, 95% CI 2.249-8.845) and developmental impairment (aOR 2.238, 95% CI 1.469-3.408). In preterm infants, the location of birth may be a key factor influencing short- and long-term outcomes. Thus, to provide adequate care and efficiently allocate medical resources to high-risk preterm infants, nationwide regional perinatal systems need to be improved and standardized.

Global incidence proportion of intraventricular haemorrhage of prematurity: a meta-analysis of studies published 2010-2020

OBJECTIVE

To investigate differences and calculate pooled incidence of any intraventricular haemorrhage (IVH), severe IVH (Grade III/IV, sIVH) and ventriculoperitoneal shunt (VPS) placement in preterm infants across geographical, health and economic regions stratified by gestational age (GA).

DESIGN

MEDLINE, Embase, CINAHL and Web of Science were searched between 2010 and 2020. Studies reporting rates of preterm infants with any IVH, sIVH and VPS by GA subgroup were included. Meta-regression was performed to determine subgroup differences between study designs and across United Nations geographical regions, WHO mortality strata and World Bank lending regions. Incidence of any IVH, sIVH and VPS by GA subgroups<25, <28, 28-31, 32-33 and 34-36 weeks were calculated using random-effects meta-analysis.

RESULTS

Of 6273 publications, 97 met inclusion criteria. Incidence of any IVH (37 studies 87 993 patients) was: 44.7% (95% CI 40.9% to 48.5%) for GA <25 weeks, 34.3% (95% CI 31.2% to 37.6%) for GA <28 weeks, 17.4% (95% CI 13.8% to 21.6%) for GA 28-31 weeks, 11.3% (95% CI 7.3% to 17.0%) for GA32-33 weeks and 4.9% (95% CI 1.4% to 15.2%) for GA 34-36 weeks. Incidence of sIVH (49 studies 328 562 patients) was 23.7% (95% CI 20.9% to 26.7%) for GA <25 weeks, 15.0% (95% CI 13.1% to 17.2%) for GA <28 weeks, 4.6% (95% CI 3.5% to 6.1%) for GA 28-31 weeks, 3.3% (95% CI 2.1% to 5.1%) for GA 32-33 weeks and 1.8% (95% CI 1.2% to 2.8%) for GA 34-36 weeks. Europe had lower reported incidence of any IVH and sIVH relative to North America (p<0.05). Proportion of VPS across all GA groups was 8.4% (95% CI 4.7% to 14.7%) for any IVH and 17.2% (95% CI 12.2% to 26.2%) for sIVH. Heterogeneity was high (I² >90%) but 64%-85% of the variance was explained by GA and study inclusion criteria.

CONCLUSIONS

We report the first pooled estimates of IVH of prematurity by GA subgroup. There was high heterogeneity across studies suggesting a need for standardised incidence reporting guidelines.

Trends in survival, perinatal morbidities and two-year neurodevelopmental outcomes in extremely low-birthweight infants over four decades

BACKGROUND

Although outcomes for infants born extremely low birthweight (ELBW; <1000 g birthweight) have improved over time, it is important to document survival and morbidity changes following the advent of modern neonatal intensive care in the 1990s.

OBJECTIVE

To describe trends in survival, perinatal outcomes and neurodevelopment to 2 years' corrected age over time across six discrete geographic cohorts born ELBW between 1979 and 2017.

METHODS

Analysis of data from discrete population-based prospective cohort studies of all live births free of lethal anomalies with birthweight 500-999 g in the state of Victoria, Australia, over 6 eras: 1979-80, 1985-87, 1991-92, 1997, 2005 and 2016-17. Perinatal data collected included survival, duration and type of respiratory support, neonatal morbidities and two-year neurodevelopmental outcomes.

RESULTS

More ELBW live births were inborn (born in a maternity hospital with a neonatal intensive care unit) over time (1979-80, 70%; 2016-17, 84%), and more were offered active care (1979-80, 58%; 2016-17, 90%). Survival to 2 years rose substantially, from 25% in 1979-80 to 80% in 2016-17. In survivors, rates of any assisted ventilation rose from 75% in 1979-80 to 99% in 2016-17. Cystic periventricular leukomalacia, severe retinopathy of prematurity and blindness improved across eras. Two-year data were available for 95% (1054/1109) of survivors. Rates of cerebral palsy, deafness and major neurodevelopmental disability changed little over time. The annual numbers with major neurodevelopmental disability increased from 12.5 in 1979-80 to 30 in 2016-17, but annual numbers free of major disability increased much more, from 31 in 1979-80 to 147 in 2016-17.

CONCLUSIONS

Active care and survival rates in ELBW children have increased dramatically since 1979 without large changes in neonatal morbidities. The numbers of survivors free of major neurodevelopmental disability have increased more over time than those with major disability.

The Incidence of Intraventricular Hemorrhage in Low-Birth-Weight Infants: Assessment by Magnetic Resonance Imaging

PURPOSE

Intraventricular hemorrhage (IVH) is common in infants with a low-birth-weight (LBW) and has been suggested to cause major impairment not only of future motor development but also of cognitive function and learning ability. The purpose of the present study is to assess the frequency of IVH using magnetic resonance imaging (MRI) in LBW infants and its clinical neurodevelopmental outcomes.

METHODS

We enrolled a consecutive series of 247 neonates with an LBW of < 1,500 g hospitalized in the newborn intensive care unit between 2010 and 2015. The presence of IVH was examined using T2* MRI at term-equivalent age (TEA). We then investigated the clinical outcome at ≥3 years of age and its correlation with the IVH grade.

RESULTS

The overall incidence of IVH among LBW infants was 16.2%. The proportion of infants with IVH showing a favorable outcome did not differ significantly from that of infants without IVH. The proportion of neonates showing a poor outcome was 6.7% for those with IVH and 1.9% for those without IVH and 2.7% for those with and without IVH combined.

CONCLUSION

We were able to clarify the frequency of IVH in LBW infants using MRI at TEA. We demonstrated the lower incidence of mortality and IVH, the higher incidence of a favorable outcome, and the lower incidence of poor outcome.

Energy expenditure and body composition in infants with bronchopulmonary dysplasia at term age

In this cross-sectional study, conducted in a cohort of infants with a gestational age of < 32 weeks, we aimed to evaluate and compare resting energy expenditure (REE) and body composition between infants who developed bronchopulmonary dysplasia (BPD) and those who did not. REE and body composition were assessed at term equivalent age using indirect calorimetry and air displacement plethysmography. Anthropometric measurements (weight, head circumference, and length) were obtained and transformed into Z-scores per the Fenton (2013) growth curve, at birth and at term equivalent age. Forty-two infants were included in this study, of which 26.2% developed BPD. Infants with BPD had significantly higher energy expenditure at term equivalent age, with no difference in body composition between the two groups.

CONCLUSION

Despite expending more energy, infants with BPD maintained a similar body composition distribution to those without BPD, and this is likely due to the recommended nutritional approach.

WHAT IS KNOWN

• Greater resting energy expenditure impairs growth of preterm infants with bronchopulmonary dysplasia.

WHAT IS NEW

• Although preterm infants with bronchopulmonary dysplasia had a higher resting energy expenditure at the corrected term age, this did not affect their body composition and growth.

Mortality and morbidity of infants with trisomy 21, weighing 1500 grams or less, in Japan

Although very low birth weight (VLBW) is well studied in neonatology and the perinatal prognosis of VLBW infants has improved over time, little is known about the prognosis of VLBW infants with trisomy 21 (T21). We aimed to investigate the mortality and morbidity of VLBW infants with T21 during NICU admission in Japan, in comparison to those of infants without birth defects (BD-). Maternal and neonatal data of infants weighing 1500 grams or less admitted to the centers of the Neonatal Research Network of Japan from 2003 to 2016 were collected prospectively. Of 60,136 infants, 328 (0.55%) had T21. Although maternal age in the case of T21 infants was higher, maternal complications tended to be less frequent than in those with BD-. Multivariable analysis revealed that morbidities were higher in infants with T21 than in those with BD- but respiratory distress syndrome and retinopathy of prematurity were less frequent in those with T21 (p < 0.001, and p = 0.014, respectively), and no significant difference was observed between the two groups in the proportion of late-onset circulatory collapse of prematurity as well as cystic periventricular leukomalacia (p = 0.739 and p = 0.733, respectively). The survival rate at discharge from the NICU was 77% and 94% for T21 and BD-, respectively. This was the first nationwide survey of VLBW infants with T21 in Japan. Although there were no data regarding the timing of diagnosis, these data will aid prenatal genetic counseling and perinatal management of T21 infants.

Growth Pattern With Morbidities From Birth to 5 Years of Age in Very Low Birth Weight Infants: Comparison of the Korean National Network and National Health Insurance Service

BACKGROUND

Long-term growth data of very low birth weight (VLBW) infants are currently collected in the Korean Neonatal Network (KNN) and National Health Insurance Service (NHIS) database. However, variance in the number of infants, check-up time, and check-up parameters led to decreased credibility of cumulated data. We aimed to compare the data on serial growth outcomes by major morbidities from birth to 5 years in VLBW infants between the KNN and NHIS databases.

METHODS

We combined the NHIS and KNN data of VLBW infants born between 2013 and 2015. The check-up times in the NHIS database were at 4-6, 9-12, 18-24, 30-36, 42-48, and 54-60 months of age, whereas in the KNN were at 18-24 months of corrected age and at 36 months of age.

RESULT

Among 8,864 VLBW infants enrolled based on the birth certificates from the Statistics Korea, 6,086 infants (69%) were enrolled in the KNN, and 5,086 infants (57%) participated in the NHIS health check-up. Among 6,068 infants, 3,428 infants (56%) were enrolled at a corrected age of 18-24 months and 2,572 infants (42%) were enrolled at a chronological age of 33-36 months according to the KNN follow-up registry. However, based on the national birth statistics data, the overall follow-up rate of the KNN at 36 months of age was as low as 29%. The NHIS screening rate was lower at first (23%); however, it increased over time to exceed the KNN follow-up rate. Growth failure (weight under 10th percentile) at corrected ages of 18-24 months and 36 months were more common in the NHIS than KNN (42% vs. 20%, 37% vs. 34.5%). Infants with bronchopulmonary dysplasia and periventricular leukomalacia showed similar rates of growth failure at 2 years but varying rates at 3 years between the KNN and NHIS.

CONCLUSION

By integrating the KNN and NHIS data indirectly at continuous time points according to morbidities, we found that there are discontinuities and discrepancies between the two databases among VLBW infants. Establishing an integrated system by patient level linking the KNN and NHIS databases can lead to better understanding and improved neonatal outcomes in VLBW infants in Korea.

Severe bronchopulmonary dysplasia in extremely premature infants: a scoping review protocol for identifying risk factors

INTRODUCTION

The remarkable improvement in the long-term prognosis of extremely premature infants has led to an increase in the number of cases of bronchopulmonary dysplasia (BPD). BPD affects pulmonary function and developmental outcomes, resulting in high chronic health burdens for infants and their families over the years. Therefore, identifying its risk factors in the early period of life and exploring better prophylactics and treatment strategies are important.The objectives of our scoping review are to screen available evidence, identify perinatal risk factors involved in the development and severity of BPD and devise a novel disease classification system that can predict long-term prognosis.

METHODS AND ANALYSIS

Eligibility criteria are as follows: articles published from 2002 to 2021; studies conducted in developed countries; articles written in English (PubMed) or Japanese (Ichushi); randomised controlled trials, prospective/retrospective cohort studies or case-control studies; extremely premature infants born before 28 weeks of gestational age; and articles in which endpoint was severe BPD as classified by the National Institute of Child Health and Human Development.We will screen the titles and abstracts of studies identified by independent reviewers using the population-concept-context framework. After a full-text review and data charting, we will provide the perinatal risk factors for severe BPD along with the risk ratio or odds ratio, 95% confidence interval and p values.

ETHICS AND DISSEMINATION

Institutional review board approval is not required due to the nature of the study. The results of this review will be disseminated through peer-reviewed publications and presentations at relevant conferences.Protocol V.1, 22 September 2021 TRIAL REGISTRATION NUMBER: UMIN000045529.