Changes in survival and neurodevelopmental outcomes of infants born at <25 weeks' gestation: a retrospective observational study in tertiary centres in Japan

National Trends in Survival and Short-Term Outcomes of Periviable Births ≤24 Weeks Gestation in the United States, 2009 to 2018

OBJECTIVE

 Data from the academic medical centers in the United States showing improvements in survival of periviable infants born at 22 to 24 weeks GA may not be nationally representative since a substantial proportion of preterm infants are cared for in community hospital-based neonatal intensive care units. Our objective was to examine the national trends in survival and other short-term outcomes among preterm infants born at ≤24 weeks gestational age (GA) in the United States from 2009 to 2018.

STUDY DESIGN

 This was a retrospective, repeated cross-sectional analysis of the National Inpatient Sample for preterm infants ≤24 weeks GA. The primary outcome was the trends in survival to discharge. Secondary outcomes were the trends in the composite outcome of death or one or more major morbidity (bronchopulmonary dysplasia, necrotizing enterocolitis stage ≥2, periventricular leukomalacia, severe intraventricular hemorrhage, and severe retinopathy of prematurity). The Cochran-Armitage trend test was used for trend analysis. p-Value <0.05 was considered significant.

RESULTS

 Among 71,854 infants born at ≤24 weeks GA, 34,251 (47.6%) survived less than 1 day and were excluded. Almost 93% of those who survived <1 day were of ≤23 weeks GA. Among the 37,603 infants included in the study cohort, 48.1% were born at 24 weeks GA. Survival to discharge at GA ≤ 23 weeks increased from 29.6% in 2009 to 41.7% in 2018 (p < 0.001), while survival to discharge at GA 24 weeks increased from 58.3 to 65.9% (p < 0.001). There was a significant decline in the secondary outcomes among all the periviable infants who survived ≥1 day of life.

CONCLUSION

 Survival to discharge among preterm infants ≤24 weeks GA significantly increased, while death or major morbidities significantly decreased from 2009 to 2018. The postdischarge survival, health care resource use, and long neurodevelopmental outcomes of these infants need further investigation.

KEY POINTS

· Survival increased significantly in infants ≤24 weeks GA in the United States from 2009 to 2018.. · Death or major morbidity in infants ≤24 weeks GA decreased significantly from 2009 to 2018.. · Death or surgical procedures including tracheostomy, VP shunt placement, and PDA surgical closure in infants <=24 weeks GA decreased significantly from 2009 to 2018..

Expectant management of preeclampsia with severe features diagnosed at less than 24 weeks

BACKGROUND

The recent American College of Obstetricians and Gynecologists Practice Bulletin offers no guidance on the management of preeclampsia with severe features at <24 weeks of gestation. Historically, immediate delivery was recommended because of poor perinatal outcomes and high maternal morbidity. Recently, advances in neonatal resuscitation have led to increased survival at periviable gestational ages.

OBJECTIVE

This study aimed to report perinatal and maternal outcomes after expectant management of preeclampsia with severe features at <24 weeks of gestation.

STUDY DESIGN

This was a retrospective case series of preeclampsia with severe features at <24 weeks of gestation at a level 4 center between 2017 and 2023. Individuals requiring delivery within 24 hours of diagnosis were excluded. Perinatal and maternal outcomes were analyzed. Categorical variables from our database were compared with previously published data using chi-square tests.

RESULTS

A total of 41 individuals were diagnosed with preeclampsia with severe features at <24 weeks of gestation. After the exclusion of delivery within 24 hours, 30 individuals (73%) were evaluated. The median gestational age at diagnosis was 22 weeks (interquartile range, 22-23). Moreover, 16% of individuals had assisted reproductive technology, 27% of individuals had chronic hypertension, 13% of individuals had pregestational diabetes mellitus, 30% of individuals had previous preeclampsia, and 73% of individuals had a body mass index of >30 kg/m2. The median latency periods at 22 and 23 weeks of gestation were 7 days (interquartile range, 4-23) and 8 days (interquartile range, 4-13). In preeclampsia with severe features, neonatal survival rates were 44% (95% confidence interval, 3%-85%) at 22 weeks of gestation and 29% (95% confidence interval, 1%-56%) at 23 weeks of gestation. There were 2 cases of acute kidney injury (7%) and 2 cases of pericardial or pleural effusions (7%). Overall perinatal survival at <24 weeks of gestation was 30% in our current study vs 7% in previous reports (P=.02).

CONCLUSION

For cases of expectant management of preeclampsia with severe features at <24 weeks of gestation, our findings showed an increased perinatal survival rate with decreased maternal morbidity compared with previously published data. This information may be used when counseling on expectant management of preeclampsia with severe features at <24 weeks of gestation.

Prognosis of 22- and 23-Gestational-Week-Old Infants at Our Facility: A Retrospective Cohort Study

OBJECTIVE

 This study aimed to compare inborn infants aged 22 and 23 gestational weeks at our hospital to assess for differences in survival and long-term prognosis.

STUDY DESIGN

 We retrospectively analyzed 22- and 23-gestational-weeks-old infants born in our hospital between January 2011 and December 2018. The prognosis of inborn infants in Japan was also calculated using the Neonatal Research Network of Japan (NRNJ) data during the same period.

RESULTS

 The survival rates at our institution's neonatal intensive care unit discharge, including stillbirth, were 72 and 89% at 22 and 23 gestational weeks, respectively. The mortality rate and neurodevelopmental impairment (NDI) rate at 3 years of age, including stillbirth, were 58 and 32% at 22 and 23 weeks, respectively. Cerebral palsy, mental developmental retardation, visual impairment, and hearing impairment defined NDI. The prognosis at our hospital was better than the average calculated using NRNJ data. Survival rates varied among facilities, and some facilities had survival rates similar to that of our hospital.

CONCLUSION

 The prognosis of 22-gestational-week-old inborn infants was inferior to that of 23 gestational weeks in our institution but was better than previously reported. If aggressive treatment is provided, survival without sequelae can be fully expected even for 22-gestational-week-old infants.

KEY POINTS

· We examined babies of gestation ages 22 and 23 weeks.. · We examined the survival and neurological prognoses.. · We compared our facility with that in entire Japan..

Two-year neurodevelopmental outcome in extremely preterm-born children: The Austrian Preterm Outcome Study Group

AIM

The current study determined the neurodevelopmental outcome of extremely preterm infants at 2 years of age.

METHODS

All live-born infants 23-27 weeks of gestation born between 2011 and 2020 in Austria were included in a prospective registry. Neurodevelopmental outcome at 2 years of corrected age was assessed using Bayley Scales of Infant Development for both motor and cognitive scores, along with a neurological examination and an assessment of neurosensory function.

RESULTS

2378 out of 2905 (81.9%) live-born infants survived to 2 years of corrected age. Follow-up data were available for 1488 children (62.6%). Overall, 43.0% had no, 35.0% mild and 22.0% moderate-to-severe impairment. The percentage of children with moderate-to-severe neurodevelopmental impairment decreased with increasing gestational age and was 31.4%, 30.5%, 23.3%, 19.0% and 16.5% at 23, 24, 25, 26 and 27 weeks gestational age (p < 0.001). Results did not change over the 10-year period. In multivariate analysis, neonatal complications as well as male sex were significantly associated with an increased risk of neurodevelopmental impairment.

CONCLUSION

In this cohort study, a 22.0% rate of moderate-to-severe neurodevelopmental impairment was observed among children born extremely preterm. This national data is important for both counselling parents and guiding the allocation of health resources.

Descriptive and Functional Genomics in Neonatal Respiratory Distress Syndrome: From Lung Development to Targeted Therapies

In this up-to-date study, we first aimed to highlight the genetic and non-genetic factors associated with respiratory distress syndrome (RDS) while also focusing on the genomic aspect of this condition. Secondly, we discuss the treatment options and the progressing therapies based on RNAs or gene therapy. To fulfill this, our study commences with lung organogenesis, a highly orchestrated procedure guided by an intricate network of conserved signaling pathways that ultimately oversee the processes of patterning, growth, and differentiation. Then, our review focuses on the molecular mechanisms contributing to both normal and abnormal lung growth and development and underscores the connections between genetic and non-genetic factors linked to neonatal RDS, with a particular emphasis on the genomic aspects of this condition and their implications for treatment choices and the advancing therapeutic approaches centered around RNAs or gene therapy.

One-year survival and outcomes of infants born at 22 and 23 weeks of gestation in Sweden 2004-2007, 2014-2016 and 2017-2019

OBJECTIVE

To explore associations between perinatal activity and survival in infants born at 22 and 23 weeks of gestation in Sweden.

DESIGN/SETTING

Data on all births at 22 and 23 weeks' gestational age (GA) were prospectively collected in 2004-2007 (T1) or obtained from national registers in 2014-2016 (T2) and 2017-2019 (T3). Infants were assigned perinatal activity scores based on 3 key obstetric and 4 neonatal interventions.

MAIN OUTCOME

One-year survival and survival without major neonatal morbidities (MNM): intraventricular haemorrhage grade 3-4, cystic periventricular leucomalacia, surgical necrotising enterocolitis, retinopathy of prematurity stage 3-5 or severe bronchopulmonary dysplasia. The association of GA-specific perinatal activity score and 1-year survival was also determined.

RESULTS

977 infants (567 live births and 410 stillbirths) were included: 323 born in T1, 347 in T2 and 307 in T3. Among live-born infants, survival at 22 weeks was 5/49 (10%) in T1 and rose significantly to 29/74 (39%) in T2 and 31/80 (39%) in T3. Survival was not significantly different between epochs at 23 weeks (53%, 61% and 67%). Among survivors, the proportions without MNM in T1, T2 and T3 were 20%, 17% and 19% for 22 weeks and 17%, 25% and 25% for 23 weeks' infants (p>0.05 for all comparisons). Each 5-point increment in GA-specific perinatal activity score increased the odds for survival in first 12 hours of life (adjusted OR (aOR) 1.4; 95% CI 1.3 to 1.6) in addition to 1-year survival (aOR 1.2; 95% CI 1.1 to 1.3), and among live-born infants it was associated with increased survival without MNM (aOR 1.3; 95% CI 1.1 to 1.4).

CONCLUSION

Increased perinatal activity was associated with reduced mortality and increased chances of survival without MNM in infants born at 22 and 23 weeks of GA.

Management and outcomes of periviable neonates born at 22 weeks of gestation: a single-center experience in Japan

OBJECTIVE

We aimed to present the active management and outcomes of infants born at 22 weeks of gestation.

STUDY DESIGN

This retrospective observational study presented the resuscitation methods, management during hospitalization, and outcomes of 29 infants born at 22 weeks of gestation who were actively resuscitated and admitted to our center during 2013-2020.

RESULTS

The survival rate was 82.8% (24/29). Tracheal intubation was performed in all patients, and surfactant was administered for 27 (93.1%). Conventional mechanical ventilation was introduced in 27 (93.1%), and this was changed to high-frequency oscillatory ventilation in more than half by day 4. Surgical treatments of patent ductus arteriosus, necrotizing enterocolitis, and retinopathy of prematurity were required in 4 (13.7%), 3 (10.3%), and 15 (51.7%) patients, respectively. No patient required a tracheostomy or ventriculoperitoneal shunt.

CONCLUSIONS

The overall survival rate and survival rate without morbidities were high among infants born at 22 weeks of gestation.

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.

Use of Fibrin Glue in the Treatment of Persistent Pneumothorax in Premature Infants at the Limit of Viability: Ethical Issues and Two and A Half Years Follow-Up

INTRODUCTION

Due to the extreme immaturity of many internal organs, including lungs, infants at the limit of viability are more predisposed to a pneumothorax (PTX). In some cases, PTX becomes persistent. Previously, only a few attempts of PTX treatment with fibrin glue were reported. However, its impact on further lung development is unknown.

CASE REPORT

We present a case of an extremely preterm infant with persistent PTX who was successfully treated with fibrin glue. In addition, we present a two-and-a-half-year corrected age follow-up focusing on respiratory problems, motor development and sensory organs. Furthermore, we touch upon the related ethical issues.

CONCLUSIONS

Fibrin glue should be used to treat persistent PTX even in an extremely preterm infant. No adverse effects were observed. At the two-and-a-half-year corrected age follow-up, despite severe bronchopulmonary dysplasia development, no serious pulmonary problems were observed. However, the child's development is uncertain. This situation raises important ethical issues concerning saving the lives of infants at the limit of viability.

Changes in In-Hospital Survival and Long-Term Neurodevelopmental Outcomes of Extremely Preterm Infants: A Retrospective Study of a Japanese Tertiary Center

OBJECTIVES

The objective of this study was to elucidate whether the survival and long-term neurodevelopmental outcomes of extremely preterm infants have improved in a Japanese tertiary center with an active treatment policy for infants born at 22-23 weeks of gestation.

STUDY DESIGN

This single-centered retrospective cohort study enrolled extremely preterm infants treated at Saitama Medical Center, Saitama Medical University, from 2003 to 2014. Patients with major congenital abnormalities were excluded. Primary outcomes were in-hospital survival and severe neurodevelopmental impairment (NDI) at 6 years of age, which was defined as having severe cerebral palsy, severe cognitive impairment, severe visual impairment, or deafness. We assessed the changes in primary outcomes between the first (period 1; 2003-2008) and the second half (period 2; 2009-2014) of the study period and evaluated the association between birth-year and primary outcomes using multivariate logistic regression models.

RESULTS

Of the 403 eligible patients, 340 (84%) survived to discharge. Among 248 patients available at 6 years of age, 43 (14%) were classified as having severe NDI. Between the 2 periods, in-hospital survival improved from 155 of 198 (78%) to 185 of 205 (90%), but severe NDI increased from 11 of 108 (10%) to 32 of 140 (23%). In multivariate logistic regression models adjusted for gestational age, birthweight, sex, singleton birth, and antenatal corticosteroids, the aOR (95% CI) of birth-year for in-hospital survival and severe NDI was 1.2 (1.1-1.3) and 1.1 (1.0-1.3), respectively.

CONCLUSION

Mortality among extremely preterm infants has improved over the past 12 years; nevertheless, no significant improvement was observed in the long-term neurodevelopmental outcomes.

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.

Regional differences of tracheostomy in extremely premature neonates across the United States

OBJECTIVE

To identify regional differences in tracheostomy rates and mortality in extremely premature neonates.

METHODS

The 1997-2019 Kids' Inpatient Databases (KID) were queried to identify children who completed 27 weeks gestation (27-wk) or less and 23 weeks gestation (23-wk) or less. Multivariable logistic regressions compared odds of tracheostomy and mortality by region (Midwest (MW), Northeast (NE), South (S), and West (W)) while controlling for demographic variables and comorbidities. Trend analyses were performed using Poisson Regressions.

RESULTS

There were 2433 27-wk or less infants and 259 23-wk or less who received a tracheostomy. The MW was the only region where higher odds of tracheostomy were seen for 27-wk or less (aOR 1.25 [95%CI 1.12-1.39]) and 23-wk or less (aOR 1.68 [95%CI 1.24-2.27]) neonates when compared to all other regions combined. The S and MW had the highest increase in tracheostomy rates of 27-wk or less (β = 5.1, r = 0.77, p = 0.025; β = 3.8, r = 0.93, p = 0.001), and the MW had the highest increased rate of tracheostomy for 23-wk or less (β = 1.9, r = 0.97, p = 0.008). There were no higher mortality odds by region in 27-wk or less. Mortality was the highest in the S for 23-wk or less (20.8%, p = 0.015).

CONCLUSIONS

This study identified regional differences in tracheostomy rates in extremely premature infants. Extremely premature neonates in the MW had higher odds of receiving a tracheostomy with comparable mortality rates to other regions. Further research is needed to analyze regional practice differences that may impact the decision to perform a tracheostomy.

Admission temperature of very low birth weight infants and outcomes at three years old

The lower body temperature of preterm newborns at admission to neonatal intensive care units (NICUs) is inversely associated with their morbidities and mortalities before discharge. This retrospective cohort study aimed to determine whether admission rectal temperature in very low birth weight infants (VLBWIs) is independently associated with a composite outcome of death or moderate-to-severe neurodevelopmental impairments as defined by a performance developmental quotient of < 70 at three years of age. VLBWIs admitted to the NICU between April 2010 and March 2016 were assesed. Developmental assessment was completed in 216 newborns. Nine and two infants died before and after discharge, respectively. A higher admission temperature was associated with a lower incidence of death or moderate-to-severe neurodevelopmental impairments with adjustment for gestational age, sex, antenatal steroid use, Apgar score, severe intraventricular hemorrhage, and severe bronchopulmonary dysplasia (odds ratio [OR] 0.424; 95% confidence interval [CI] 0.250-0.717; p = 0.001). The admission temperature remained as an independent variable of adverse outcome at three years of age even when the study cohort was limited to surviving infants (OR 0.448; 95% CI 0.259-0.774; p = 0.004). Further studies are needed to assess whether avoiding low body temperature at admission results in better long-term neurodevelopmental outcomes in VLBWIs.

Respiratory management for extremely premature infants born at 22 to 23 weeks of gestation in proactive centers in Sweden, Japan, and USA

Survival of preterm newborn infants have increased steadily since the introduction of surfactant treatment and antenatal steroids. In the absence of randomized controlled trials on ventilatory strategies in extremely preterm infants, we present ventilatory strategies applied during the initial phase and the continued ventilatory care as applied in three centers with proactive prenatal and postnatal management and well documented good outcomes in terms of mortality and morbidity in this cohort of infants.

Mortality, In-Hospital Morbidity, Care Practices, and 2-Year Outcomes for Extremely Preterm Infants in the US, 2013-2018

IMPORTANCE

Despite improvement during recent decades, extremely preterm infants continue to contribute disproportionately to neonatal mortality and childhood morbidity.

OBJECTIVE

To review survival, in-hospital morbidities, care practices, and neurodevelopmental and functional outcomes at 22-26 months' corrected age for extremely preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

Prospective registry for extremely preterm infants born at 19 US academic centers that are part of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. The study included 10 877 infants born at 22-28 weeks' gestational age between January 1, 2013, and December 31, 2018, including 2566 infants born before 27 weeks between January 1, 2013, and December 31, 2016, who completed follow-up assessments at 22-26 months' corrected age. The last assessment was completed on August 13, 2019. Outcomes were compared with a similar cohort of infants born in 2008-2012 adjusting for gestational age.

EXPOSURES

Extremely preterm birth.

MAIN OUTCOMES AND MEASURES

Survival and 12 in-hospital morbidities were assessed, including necrotizing enterocolitis, infection, intracranial hemorrhage, retinopathy of prematurity, and bronchopulmonary dysplasia. Infants were assessed at 22-26 months' corrected age for 12 health and functional outcomes, including neurodevelopment, cerebral palsy, vision, hearing, rehospitalizations, and need for assistive devices.

RESULTS

The 10 877 infants were 49.0% female and 51.0% male; 78.3% (8495/10848) survived to discharge, an increase from 76.0% in 2008-2012 (adjusted difference, 2.0%; 95% CI, 1.0%-2.9%). Survival to discharge was 10.9% (60/549) for live-born infants at 22 weeks and 94.0% (2267/2412) at 28 weeks. Survival among actively treated infants was 30.0% (60/200) at 22 weeks and 55.8% (535/958) at 23 weeks. All in-hospital morbidities were more likely among infants born at earlier gestational ages. Overall, 8.9% (890/9956) of infants had necrotizing enterocolitis, 2.4% (238/9957) had early-onset infection, 19.9% (1911/9610) had late-onset infection, 14.3% (1386/9705) had severe intracranial hemorrhage, 12.8% (1099/8585) had severe retinopathy of prematurity, and 8.0% (666/8305) had severe bronchopulmonary dysplasia. Among 2930 surviving infants with gestational ages of 22-26 weeks eligible for follow-up, 2566 (87.6%) were examined. By 2-year follow-up, 8.4% (214/2555) of children had moderate to severe cerebral palsy, 1.5% (38/2555) had bilateral blindness, 2.5% (64/2527) required hearing aids or cochlear implants, 49.9% (1277/2561) had been rehospitalized, and 15.4% (393/2560) required mobility aids or other supportive devices. Among 2458 fully evaluated infants, 48.7% (1198/2458) had no or mild neurodevelopmental impairment at follow-up, 29.3% (709/2419) had moderate neurodevelopmental impairment, and 21.2% (512/2419) had severe neurodevelopmental impairment.

CONCLUSIONS AND RELEVANCE

Among extremely preterm infants born in 2013-2018 and treated at 19 US academic medical centers, 78.3% survived to discharge, a significantly higher rate than for infants born in 2008-2012. Among infants born at less than 27 weeks' gestational age, rehospitalization and neurodevelopmental impairment were common at 2 years of age.

Evaluation of the social skills of low birthweight infants using the Interaction Rating Scale

[Purpose] This study aimed to examine, using the Interaction Rating Scale, the effect of social skills at 18 months of life on the subsequent development of low birthweight infants. [Participants and Methods] The study participants were made up of a total of 23 infants who were admitted to the neonatal intensive care unit of Hospital A and whose developmental indexes were followed up at the outpatient clinic for up to 3 years of age. The survey was conducted twice in each infant, at a corrected age of 18 months and at 36 full months of age. Social skills and developmental indexes were assessed at the corrected age of 18 months, meanwhile only developmental indexes were assessed at 36 full months, to examine associations. The Interaction Rating Scale was used to assess social skills. This scale measures various aspects of social development by observing caregiver-child interactions in situations wherein children are engaged in tasks more difficult for their age. [Results] The results demonstrated that social skills at 18 months were associated with the developmental indexes at 18 and 36 months, whereas more items were associated with the developmental index at 36 months. [Conclusion] The results indicate the need for early prediction of developmental delay and timely intervention, by assessing social skills in low birthweight infants.

Foetal growth, birth transition, enteral nutrition and brain light scattering

If the brain structure is assessed at neonatal intensive care units, covert clinical events related with subtle brain injury might be identified. The reduced scattering coefficient of near-infrared light (μ_S’) obtained using time-resolved near-infrared spectroscopy from the forehead of infants is associated with gestational age, body weight and Apgar scores, presumably reflecting subtle changes of the brain related to foetal growth and birth transition. One hundred twenty-eight preterm and term infants were studied to test whether μ_S’ obtained from the head at term-equivalent age is associated with foetal growth, birth transition and nutritional status after birth, which are key independent variables of developmental outcomes. As potential independent variables of μ_S’, birth weight, Apgar scores, age at full enteral feeding and post-conceptional age at the study were assessed to represent foetal growth, birth transition and nutritional status after birth. Subsequently, higher μ_S’ values were associated with higher Apgar scores (p = 0.003) and earlier establishment of enteral feeding (p < 0.001). The scattering property of near-infrared light within the neonatal brain might reflect changes associated with birth transition and nutritional status thereafter, which might be used as a non-invasive biomarker to identify covert independent variables of brain injury in preterm infants.

Does a Split-Week Gestational Age Model Provide Valuable Information on Neurodevelopmental Outcomes in Extremely Preterm Infants?

Our primary objective for this follow-up study was to compare the neurodevelopmental outcomes of a surviving cohort of infants using a split-week gestational model (early versus late) gestational age (GA) and the standard completed GA categorization. Neurodevelopmental outcomes using a split-week GA model defined as early (X, 0–3) and late (X, 4–6), with X being 23–26 weeks GA, were compared to outcomes using completed weeks GA. In total, 1012 infants were included in the study. Statistically significant differences were noted in outcomes between the early and late split of the gestational week at 23 weeks (early vs. late), with 13.3% vs. 54.5% for no neurodevelopmental impairment, and 53.3% vs. 22.7% for significant impairment (p = 0.034), respectively. There were no differences seen in the split week model for 24, 25, and 26 weeks. A trend towards improved neurodevelopmental outcomes was seen with each increasing gestation week. The split-week model did not provide additional information for pregnancies and infants between 24 and 26 weeks gestation. It did, however, provide information for counsel for infants at 23 weeks gestation, showing benefits in the late versus early half of the week.

AK, Murki S, Roehr CC. ELBW and ELGAN outcomes in developing nations-Systematic review and meta-analysis

Context

Morbidity and mortality amongst extremely low birth weight (ELBW) and extremely low gestational age neonates (ELGANs) in developing nations has not been well studied.

Objectives

Evaluate survival until discharge, short- and long-term morbidities of ELBW and ELGANs in LMICs.

Data sources

CENTRAL, EMBASE, MEDLINE and Web of Science.

Study selection

Prospective and retrospective observational studies were included.

Data extraction and synthesis

Four authors extracted data independently. Random-effects meta-analysis of proportions was used to synthesize data, modified QUIPS scale to evaluate quality of studies and GRADE approach to ascertain the certainty of evidence (CoE).

Results

192 studies enrolling 22,278 ELBW and 18,338 ELGANs were included. Survival was 34% (95% CI: 31% - 37%) (CoE–low) for ELBW and 39% (34% - 44%) (CoE—moderate) for ELGANs. For ELBW neonates, the survival for low-income (LI), lower middle-income (LMI) and upper middle income (UMI) countries was 18% (11% - 28%), 28% (21% - 35%) and 39% (36% - 42%), respectively. For ELGANs, it was 13% (8% - 20%) for LI, 28% (21% - 36%) for LMI and 48% (42% - 53%) for UMI countries. There was no difference in survival between two epochs: 2000–2009 and 2010–2020. Except for necrotising enterocolitis [ELBW and ELGANs—8% (7% - 10%)] and periventricular leukomalacia [ELBW—7% (4% - 11%); ELGANs—6% (5%-7%)], rates of all other morbidities were higher compared to developed nations. Rates of neurodevelopmental impairment was 17% (7% - 34%) in ELBW neonates and 29% (23% - 37%) in ELGANs.

Limitations

CoE was very low to low for all secondary outcomes.

Conclusions

Mortality and morbidity amongst ELBW and ELGANs is still a significant burden in LMICs. CoE was very low to low for all the secondary outcomes, emphasizing the need for high quality prospective cohort studies.

Trial registration

PROSPERO (CRD42020222873).

Gestation-Based Viability-Difficult Decisions with Far-Reaching Consequences

Most clinicians rely on outcome data based on completed weeks of gestational of fetal maturity for antenatal and postnatal counseling, especially for preterm infants born at the margins of viability. Contemporary estimation of gestational maturity, based on ultrasounds, relies on the use of first-trimester scans, which offer an accuracy of ±3-7 days, and depend on the timing of the scans and the measurements used in the calculations. Most published literature on the outcomes of babies born prematurely have reported on short- and long-term outcomes based on completed gestational weeks of fetal maturity at birth. These outcome data change significantly from one week to the next, especially around the margin of gestational viability. With a change in approach solely from decisions based on survival, to disability-free survival and long-term functional outcomes, the complexity of the parental and care provider's decision-making in the perinatal and postnatal period for babies born at less than 25 weeks gestation remains challenging. While sustaining life following birth at the margins of viability remains our priority-identifying and mitigating risks associated with extremely preterm birth begins in the perinatal period. The challenge of supporting the normal maturation of these babies postnatally has far-reaching consequences and depends on our ability to sustain life while optimizing growth, nutrition, and the repair of organs compromised by the consequences of preterm birth. This article aims to explore the ethical and medical complexities of contemporary decision-making in the perinatal and postnatal periods. We identify gaps in our current knowledge of this topic and suggest areas for future research, while offering a perspective for future collaborative decision-making and care for babies born at the margins of viability.

Neurodevelopmental outcomes of very low birth weight infants in the Neonatal Research Network of Japan: importance of neonatal intensive care unit graduate follow-up

Here we describe the neurodevelopmental outcomes of very low birth weight (VLBW) infants (birth weight ≤1,500 g) at 3 years of age in the Neonatal Research Network of Japan (NRNJ) database in the past decade and review the methodological issues identified in follow-up studies. The follow-up protocol for children at 3 years of chronological age in the NRNJ consists of physical and comprehensive neurodevelopmental assessments in each participating center. Neurodevelopmental impairment (NDI)-moderate to severe neurological disability-is defined as cerebral palsy (CP) with a Gross Motor Function Classification System score ≥2, visual impairment such as uni- or bilateral blindness, hearing impairment requiring hearing amplification, or cognitive impairment with a developmental quotient (DQ) of Kyoto Scale of Psychological Development score <70 or judgment as delayed by pediatricians. We used death or NDI as an unfavorable outcome in all study subjects and NDI in survivors using number of assessed infants as the denominator. Follow-up data were collected from 49% of survivors in the database. Infants with follow-up data had lower birth weights and were of younger gestational age than those without followup data. Mortality rates of 40,728 VLBW infants born between 2003 and 2012 were 8.2% before discharge and 0.7% after discharge. The impairment rates in the assessed infants were 7.1% for CP, 1.8% for blindness, 0.9% for hearing impairment, 15.9% for a DQ <70, and 19.1% for NDI. The mortality or NDI rate in all study subjects, including infants without followup data, was 17.4%, while that in the subjects with outcome data was 32.5%. The NRNJ follow-up study results suggested that children born with a VLBW remained at high risk of NDI in early childhood. It is important to establish a network followup protocol and complete assessments with fewer dropouts to enable clarification of the outcomes of registered infants.

Care practices and outcomes of extremely preterm neonates born at 22-24 weeks -A single centre experience

BACKGROUND

Wide variation in the care practices and survival rates of neonates born at peri-viable gestational ages of 22 +0 -24 +6 weeks exists. This study elucidates the postnatal risk factors for morbidity/mortality, contrasts the care practices and short-term outcomes of this vulnerable group of preterm neonates from a single center with others.

METHODS

Retrospective study of neonates born at 22 +0 -24 +6 weeks in a level 3 neonatal intensive care unit in UK, over a period of 4 years (2016-2019).

RESULTS

94 neonates given active care studied. Survival until discharge was 51.1%(22-23 wks -44%, 24 wks -59.1%) and survival with no major brain injury (MBI) [grade III/IV IVH, cystic periventricular leukomalacia] was 38.3%(22-23 wks -32%, 24 wks -45.4%). Of those who survived until discharge, 75%had no MBI (22-23 wks -72.7%, 24 wks -76.9%). Neonates requiring significant respiratory support within first 72 hours as well as needing rescue high frequency ventilation had significantly high risk of mortality or MBI [aOR -7.17 (2.24-25.79), p = 0.00; 4.76 (1.43-20.00), p = 0.01].

CONCLUSIONS

Survival rate differed from other centres. MBI was low amongst survivors. Severe respiratory disease in the initial days was associated with a higher risk of death or MBI.

Association between mode of delivery and infant survival at 22 and 23 weeks of gestation

BACKGROUND

Cesarean delivery is currently not recommended before 23 weeks' gestation unless for maternal indications, even in the setting of malpresentation. These recommendations are based on a lack of evidence of improved neonatal outcomes and survival following cesarean delivery and the maternal risks associated with cesarean delivery at this early gestational age. However, as neonatal resuscitative measures and obstetrical interventions improve, studies evaluating the potential neonatal benefit of periviable cesarean delivery have reported inconsistent findings.

OBJECTIVE

This study aimed to compare the survival rates at 1 year of life among resuscitated infants delivered by cesarean delivery with those delivered vaginally at 22 and 23 weeks of gestation.

STUDY DESIGN

We conducted a population-based cohort study of all resuscitated livebirths delivered between 22 0/7 and 23 6/7 weeks of gestational age in the United States between 2007 and 2013. The primary outcome was the rate of infant survival at 1 year of life for different routes of delivery (cesarean vs vaginal delivery) at both 22 and 23 weeks of gestation. The secondary outcome variables included infant survival rates for neonates who survived beyond 24 hours of life, neonatal survival, and the length of survival. A secondary analysis also included a comparison of the infant survival rates between the different routes of delivery cohorts stratified by fetal presentation, steroid exposure, and ventilation. Information about composite adverse maternal outcomes were limited to infants who were delivered between 2011 and 2013 (when these items were first reported) and were defined as a requirement for blood transfusion, an unplanned operating room procedure following delivery, unplanned hysterectomy, and intensive care unit admission; the composite adverse maternal outcomes were also compared between the different delivery route cohorts for deliveries occurring between 22 and 23 weeks of gestation. Multivariable logistic regression analysis was used to determine the association between cesarean delivery and infant survival and other neonatal and maternal outcomes.

RESULTS

Resuscitated infants delivered by cesarean delivery had higher rates of survival at 22 weeks (44.9 vs 23.0%; P<.001) and at 23 weeks (53.3 vs 43.4%; P<.001) of gestation regardless of fetal presentation. Multivariable logistic regression analysis demonstrated that infants who were delivered by cesarean delivery at 22 weeks (adjusted relative risk, 2.3; 95% confidence interval, 1.9-2.8) and 23 weeks (adjusted relative risk, 1.4; 95% confidence interval, 1.2-1.5) of gestation were more likely to survive than those delivered vaginally. When the cohort was limited to neonates who survived beyond the first 24 hours of life, vertex neonates born by cesarean delivery were not more likely to survive at 22 weeks (adjusted relative risk, 1.2; 95% confidence interval, 0.9-1.7) or 23 weeks (adjusted relative risk, 1.1; 95% confidence interval, 0.9-1.3) of gestation. An increased risk for composite adverse maternal outcomes (adjusted relative risk, 1.7; 95% confidence interval, 1.1-2.7) was associated with cesarean delivery at 22 to 23 weeks of gestation.

CONCLUSION

Cesarean delivery is associated with increased survival at 1 year of life among resuscitated, periviable infants born between 22 0/7 and 23 6/7 weeks of gestation, especially in the setting of nonvertex presentation. However, cesarean delivery is associated with increased maternal morbidity.

Promoting sound development of preterm infants in the name of developmental neuroscience: Beyond advanced life support and neuroprotection

Despite the increased survival opportunities for extremely preterm infants, their long-term cognitive outcomes remain poor, with increased incidence of cognitive impairments in childhood and reduced opportunities to attend higher education in young adulthood compared to their term-born peers. Given that a considerable fraction of preterm infants develop cognitive impairments even without apparent sentinel events at birth and cerebral lesions on MRI assessed at term equivalent age, future strategies to improve the outcome may need to address cerebral dysfunction, which cannot be explained by the classical understanding of the injury cascade triggered by hypoxia-ischaemia around birth. Developmental care has been proposed to minimize neurodevelopmental impairments related to preterm birth. However, considerable modes of cares, environmental settings and procedures provided by the developmental care of current style appear to offer little benefit to the sound development of infants. Although it is obvious that advanced life support and neuroprotective treatments fall far short in compensating for the burden of preterm birth, researchers need to make further effort to fill the knowledge gap in the cerebral function of foetuses and newborn infants before establishing evidence-based developmental care. Clinicians need to develop an ability to translate the findings from basic and translational studies incorporating their potential biases and limitations. Care for newborn infants needs to be reassessed, including but not limited to developmental care, in the context that any sensory input and motor reaction of preterm infants may ultimately affect their cognitive functioning.

Improved Survival of Periviable Infants after Alteration of the Threshold of Viability by the Neonatal Resuscitation Program 2015

Periviable infants (PIs) born at 22–25 weeks gestational age (wGA) have a variable survival rate (49.7–86.2%) among hospitals. One factor involved in this difference may be the definition of the threshold of viability. The American Academy of Pediatrics revised the neonatal resuscitation program in late 2015 (NRP 2015) and altered the threshold of viability from 23 to 22 wGA. The impact on the survival of PIs after the guideline alteration has seldom been discussed. Since 2016, the unit of this study has implemented the renewed guideline for PIs. We retrospectively reviewed and analyzed the survival and clinical variables of PIs before and after implementation of the guideline, which included a 10-year cohort in a single center in Taiwan. There were 168 PIs enrolled between 2010 and 2019 (Epoch-I, 2010–2015; Epoch-II, 2016–2019), after excluding those with congenital anomalies and parent-decided comfort care. Compared to those in Epoch-I, the PIs in Epoch-II had significantly higher odds ratios (2.602) (95% confidence interval: 1.170–5.789; p = 0.019) for survival. Younger gestational age, small size for gestational age, cesarean delivery, low blood pH at birth, and surfactant therapeutic treatment were found to be significant risk factors associated with the survival of PIs (p < 0.05 for each). The altered threshold of viability by NRP 2015 may impact the survival of PIs. However, long-term follow-up for surviving PI is required in the future.

Frühgeborene an der Grenze der Lebensfähigkeit (Entwicklungsstufe S2k, AWMF-Leitlinien-Register Nr. 024/019, Juni 2020)

Redaktionskomitee Federführende Fachgesellschaft

Prematurity at less than 24 weeks of gestation is a risk for prolonged hyperglycemia in extremely low-birth weight infants

Hyperglycemia in extremely low-birth weight infants (ELBWIs) is frequently observed during the acute perinatal phase, (i.e., first 1-2 weeks postnatal period); however it can occasionally persists for >2 weeks, extending to the post-acute phase. Since such prolonged hyperglycemia (PH) is not typical for ELBWIs, the aim of the present study was to further understand the clinical details of PH. Twenty-five hyperglycemic ELBWIs born before 28 weeks of gestation from 2015 to 2018 were included in the study. Based on the duration of hyperglycemia, we separated the subjects into two groups: non-prolonged hyperglycemia (NPH) who achieved remission within ≤2 weeks [n = 18, median 3.0 (range, 2.0-4.0) days], and PH, whose hyperglycemia persisted for >2 weeks [n = 7, median 50.0 (range, 33.5-66.0) days]. Compared to the NPH group, glucose metabolism of the PH group was more deteriorate. The peak blood glucose level was significantly higher in the PH group [PH: median 472 mg/dL, NPH: median 275 mg/dL, p < 0.001], and a higher proportion of subjects in the PH group required insulin therapy [PH: 100% (7/7) vs. NPH: 22% (4/22)]. Multivariate analysis revealed that among perinatal factors, prematurity was the only independent risk factor for PH (glucocorticoid therapy: p = 0.884, gestational age: p = 0.006), with a cutoff of 23W4D determined by receiver operating characteristic analysis. Our data revealed distinctive clinical features of PH, suggesting a type different from the previously reported hyperglycemia in ELBWIs. Specifically, extreme prematurity, less than 24 weeks of gestation, is a risk for PH, and aggressive interventions, such as insulin would be required.

Analysis of neurodevelopmental outcomes of preadolescents born with extremely low weight revealed impairments in multiple developmental domains despite absence of cognitive impairment

BACKGROUND AND AIMS

Children with extremely low-birth weight (ELBW) have a high risk for cognitive, motor, and attention impairments and learning disabilities. Longitudinal follow-up studies to a later age are needed in order to increase understanding of the changes in neurodevelopmental trajectories in targeting timely intervention. The aims of this study were to investigate cognitive and motor outcomes, attention-deficit hyperactivity (ADHD) behaviour, school performance, and overall outcomes in a national cohort of ELBW children at preadolescence, and minor neuromotor impairments in a subpopulation of these children and to compare the results with those of full-term controls. The additional aim was to report the overall outcome in all ELBW infants born at 22 to 26 gestational weeks.

METHODS

This longitudinal prospective national cohort study included all surviving ELBW (birth weight <1000 g) children born in Finland in 1996 to 1997. No children were excluded from the study. Perinatal, neonatal, and follow-up data up to the age of 5 years of these children were registered in the national birth register. According to birth register, the study population included all infants born at the age under 27 gestational weeks. At 11 years of age general cognitive ability was tested with the Wechsler Intelligence Scale for Children, ADHD behavior evaluated with a report from each child's own teacher (ADHD Rating Scale IV), and school performance with a parental questionnaire. An ELBW subpopulation consisting of a cohort representative children from the two university hospitals from two regions (n = 63) and the age-matched full-term born controls born in Helsinki university hospital (n = 30) underwent Movement Assessment Battery for Children and Touwen neurological examination comprising developmental coordination disorder (DCD) and minor neurological dysfunction (MND), respectively.

RESULTS

Of 206 ELBW survivors 122 (73% of eligible) children and 30 (100%) full-term control children participated in assessments. ELBW children had lower full-scale intellectual quotient than controls (t-test, 90 vs 112, P < .001), elevated teacher- reported inattention scores (median = 4.0 vs 1.0, P = .021, r = .20) and needed more educational support (47% vs 17%, OR 4.5, 95% CI 1.6-12.4, P = .02). In the subpopulation, the incidences of DCD were 30% in ELBW and 7% in control children (P = .012, OR 6.0 CI 1.3-27.9), and complex MND 12.5% and 0%, (P = .052; RR 1.1 95% CI 1.04-1.25), respectively. Of survivors born in 24 to 26 gestational weeks, 29% had normal outcome.

CONCLUSION

As the majority of the extremely preterm born children had some problems, long-term follow-up is warranted to identify those with special needs and to design individual multidisciplinary support programs.

Outcomes of neonates born at <26 weeks gestational age who receive extensive cardiopulmonary resuscitation compared with airway and breathing support

OBJECTIVE

To evaluate outcomes of preterm infants <26 weeks gestational age (GA) following postdelivery extensive cardiopulmonary resuscitation (ECPR) compared with airway and breathing support (ABS).

STUDY DESIGN

Retrospective review of Canadian Neonatal Network data during January 2010 to December 2016. The primary outcome was death or severe morbidity (intraventricular hemorrhage ≥grade 3 or periventricular leucomalacia, retinopathy of prematurity ≥stage 3, bronchopulmonary dysplasia, or necrotizing enterocolitis).

RESULT

Among 3633 infants analyzed, 433 (11.9%) received ECPR. In multivariable analysis, death or severe morbidity was higher in the ECPR versus ABS group [adjusted odds ratio 2.26 (95% confidence interval 1.49, 3.43)]. The majority of the difference was due to increased mortality, which occurred mostly during the first week of life.

CONCLUSION

These data from a recent cohort of infants near the limits of viability may be useful for prognostication for health care providers and counseling of parents.

Outcomes at 18 to 22 Months of Corrected Age for Infants Born at 22 to 25 Weeks of Gestation in a Center Practicing Active Management

OBJECTIVE

To assess the outcomes in actively managed extremely preterm infants after admission to a neonatal intensive care unit.

STUDY DESIGN

Retrospective cohort of 255 infants born at 22-25 weeks of gestation between 2006 and 2015 at a single study institution. Infants were excluded for congenital anomaly, death in delivery room, or parental request for palliation (n = 7). Neurodevelopmental outcomes were analyzed for 169 of 214 survivors (78.9%) at 18-22 months of corrected age. Outcomes were evaluated using the Mann-Whitney U, χ², or Fisher exact test, where appropriate. In addition, cognitive scores of the Bayley Scales of Infant-Toddler Development (3rd edition) were assessed using generalized estimating equations.

RESULTS

Seventy infants born at 22-23 weeks of gestation (22 weeks, n = 20; 23 weeks, n = 50) and 178 infants born at 24-25 weeks of gestation (24 weeks, n = 79; 25 weeks, n = 99 infants) were included. Survival to hospital discharge of those surviving to NICU admission was 78% (55/70; 95% CI, 69%-88%) at 22-23 weeks and 89% (159/178; 95% CI, 84%-93% at 24-25 weeks; P = .02). No or mild neurodevelopmental impairment in surviving infants was 64% (29/45; 95% CI, 50%-77%) at 22-23 weeks and 76% (94/124; 95% CI, 68%-83%; P = .16) at 24-25 weeks.

CONCLUSIONS

Although survival was lower in infants born at 22-23 weeks than at 24-25 weeks of gestation, the majority of survivors in both groups had positive outcomes with no or mild neurodevelopmental impairments. Further evaluation of school performance is warranted.

Prognosis of preterm premature rupture of membranes between 20 and 24 weeks of gestation: A retrospective cohort study

Background

The previous study on prognosis of preterm premature rupture of fetal membranes (pPROM) near the limit of viability showed various survival rate raging from 26 to 57 %%. This may be partly due to the fact that treatment of prematurely born babies vary from one country to another, or sometimes within a single country. In Japan, resuscitation efforts are made to newborns of early gestational age, normally from 22 weeks of gestation.

Objective

To assess the natural history and short- and long-term prognosis in pregnancies complicated by preterm premature rupture of membranes (pPROM) near the limit of viability in a hospital in Japan.

Method

We conducted a single-center retrospective cohort study. Cases with diagnosis of pPROM at a gestational age of 20–23 6/7 weeks and delivered in our hospital between April 2007 and December 2017 were examined.

Result

66 cases were included and of those, 54 (81.1 %) newborns survived to discharge. Of the neonates who survived to discharge, 42 (77.8 % of survivors) experienced severe morbidity at the time of discharge. Multivariate logistic regression analysis showed that later gestational age at pPROM and longer latency period were significantly associated with survival with no severe morbidities (per one day increase, adjusted odds ratio (OR) 1.37, 95 % CI 1.03–1.83, p = 0.033 and per one day increase, adjusted OR 1.11, 95 % CI 1.02–1.21, p = 0.015). Of 23 cases followed at 36 months, 8 (34.8 %) showed developmental delay.

Conclusion

The survival rate was significantly higher than the previous studies, yet many of the survivors experienced short-term severe morbidity. Of those who experienced short-term severe morbidity, however, more than half showed normal range development at 36 months.

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.