Changes in Survival Rate for Very-Low-Birth-Weight Infants in Korea: Comparison with Other Countries

Evaluation of timed dexamethasone eye drops to prevent proliferative retinopathy of prematurity: a study protocol for a randomized intervention, multi-centre, double-blinded trial (DROPROP)

BACKGROUND

As the survival rate of preterm infants continues to rise worldwide, more infants are at risk of developing sight-threatening retinopathy of prematurity (ROP). Destructive retinal laser treatment and intravitreal injections of anti-vascular endothelial growth factor (VEGF), factor, which have potential systemic side effects, are necessary to prevent blindness in severe cases of ROP. Off-label use in clinical settings suggests that dexamethasone eye drops, 1 mg/ml, may prevent the progression of ROP to severe disease (Type 1 ROP) requiring treatment. Our current study aims to assess the efficacy and safety of timely administered dexamethasone eye drops to reduce the need for laser or anti-VEGF ROP treatment in preterm infants.

METHODS

In a randomized prospective interventional, multi-centre, double-blinded trial, we plan to include 100 infants with severe ROP born before gestational age 30 weeks in Sweden. Infants will be randomized to intervention with dexamethasone eye drops (1 mg/ml) (n = 50) or placebo, saline (n = 50) until either ROP is resolved or severe ROP (Type 1 ROP) development occurs, fulfilling ROP treatment criteria. Eye drops will be administered one drop per day or every other day, depending on the severity of ROP, with a maximum duration of 12 weeks. The primary objective is to evaluate whether dexamethasone intervention reduces the proportion of infants developing Type 1 ROP compared to infants receiving a placebo. Adverse events and potential side effects will be recorded, such as high intraocular pressure and growth restriction. Levels of cortisol in saliva and glucose in urine will be measured repeatedly. Secondary outcomes will include the timing of ROP progression, the recurrence rate after ROP treatment and retinal morphology. An ophthalmological follow-up will be initiated at 2 and 5.5 years of age, evaluating visual acuity, refractive errors, strabismus, retinal morphology and ophthalmological complications. All outcomes in the study will be compared between the infants receiving dexamethasone intervention and those receiving placebo.

DISCUSSION

Timely administration of dexamethasone eye drops may prevent severe ROP from progressing to Type 1 ROP, which requires treatment. This study aims to assess the efficacy and safety of dexamethasone intervention to support its clinical use and national guidelines.

TRIAL REGISTRATION

EudraCT, 2020-004933-19, registered in January 2021 and CTIS, 2023-505318-97-00, registered in August 2023.

CLINICAL TRIAL NUMBER

Not applicable.

Rising public costs of preterm infant hospitalization in South Korea from a nationwide observational study

Despite the decline in the overall birth rate, increasing preterm births and associated medical costs pose a national concern. We analyze hospitalization costs covered by national public insurance for preterm infants. Population-based data, obtained from the National Health Insurance Service (NHIS), which is operated by the Health Insurance Review and Assessment Service, were used for the study. Preterm births from January 1, 2008 to December 31, 2020 were included, using International Classification of Diseases and Related Health Problems, 10th edition (P07.2, extremely preterm < 28 weeks gestational age, P07.3, non-extremely preterm). The primary outcomes related to cost from the first hospitalization due to preterm births and medication, and laboratory, radiological, and functional tests by gestational age and birth weight. Additionally, we assessed the readmission rates of preterm infants and the associated medical costs. A total of 5,312,886 live infants were born, of which 90,575 were claimed as preterm birth hospitalization. The total medical cost per patient increased almost three-fold from $7,390.90 to $20,209.59 from 2008 to 2020; for the extremely preterm group, it increased four-fold ($13,961.03 to $55,984.47). The readmission rate within 90 days of discharge was 62.5%; however, a greater proportion of the extremely preterm, as compared to the non-extremely preterm (16.1% vs. 8.32%, P < 0.001) group was readmitted within 30 days. The extremely preterm group also incurred higher costs associated with readmission (mean $4293.8 vs. $2975.4, P < 0.001). This study reveals not only the increase in preterm birth rate in South Korea, but also in the associated medical costs. Further attention should be paid to efficient resource allocation at the national level to relieve the medical burden of preterm births.

Survival outcomes among periviable infants: a systematic review and meta-analysis comparing different income countries and time periods

Background

Periviable infants are a highly vulnerable neonatal group, and their survival rates are considerably affected by patient-, caregiver-, and institution-level factors, exhibiting wide variability across different income countries and time periods. This study aims to systematically review the literature on the survival rates of periviable infants and compare rates among countries with varied income levels and across different time periods.

Methods

Comprehensive searches were conducted across MEDLINE, Embase, CENTRAL, and Web of Science. Cohort studies reporting survival outcomes by gestational age (GA) for periviable infants born between 22 + 0 and 25 + 6 weeks of gestation were considered. Paired reviewers independently extracted data and assessed the risk of bias and quality of evidence. Data pooling was achieved using random-effects meta-analyses.

Results

Sixty-nine studies from 25 countries were included, covering 56,526 live births and 59,104 neonatal intensive care unit (NICU) admissions. Survival rates for infants born between 22 and 25 weeks of GA ranged from 7% (95% CI 5-10; 22 studies, n = 5,658; low certainty) to 68% (95% CI 63-72; 35 studies, n = 21,897; low certainty) when calculated using live births as the denominator, and from 30% (95% CI 25-36; 31 studies, n = 3,991; very low certainty) to 74% (95% CI 70-77; 48 studies, n = 17,664, very low certainty) for those admitted to NICUs. The survival rates improved over the two decades studied; however, stark contrasts were evident across countries with varying income levels.

Conclusion

Although the survival rates for periviable infants have improved over the past two decades, substantial disparities persist across different economic settings, highlighting global inequalities in perinatal health. Continued research and collaborative efforts are imperative to further improve the global survival and long-term outcomes of periviable infants, especially those in Low- and Middle-Income Countries.

Systematic review registration

PROSPERO, CRD42022376367, available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022376367.

Machine-learning-based evaluation of the usefulness of lactate for predicting neonatal mortality in preterm infants

BACKGROUND

Unlike in adult and pediatric patients, the usefulness of lactate in preterm infants has not been thoroughly discussed. This study aimed to evaluate whether the lactate level in the first hours of life is an important factor associated with neonatal death in very-low-birth-weight (VLBW) preterm infants.

METHODS

Electronic medical records from a level 4 neonatal intensive care unit in South Korea were reviewed to obtain perinatal and neonatal outcomes. Data on lactate levels of preterm infants in the first 12 h of life were collected. Neonatal mortality and morbidities were compared based on lactate levels. Subsequently, machine-learning models incorporating 20 independent variables, both with and without lactate, were compared for model performances and feature importance of lactate for predicting in-hospital mortality in the applicable models.

RESULTS

One hundred and sixty-eight preterm infants were included. Death rates on days 7 and 30 of life (D30-mortality) were significantly higher in infants with high lactate levels (≥3rd interquartile range) than in those with lower levels (<3rd interquartile range). Though statistically insignificant, the overall in-hospital mortality was more than twice as high in the high lactate level group than in the lower lactate level group. Based on the machine learning results, Random Forest, Gradient Boosting, and LightGBM models all showed greater area under the curves when lactate was included. Lactate consistently ranked in the variables of top five feature importance, particularly showing the greatest value in the Gradient Boosting model.

CONCLUSION

Lactate levels during the early hours of life may be an important factor associated with in-hospital death of preterm VLBW infants. Based on the enhanced performance of the above-mentioned machine learning models, lactate levels in the early postnatal period may add to assessing the clinical status and predicting the hospital course in this population.

Trends in Prevalence and Incidence of Epilepsy and Drug-Resistant Epilepsy in Children: A Nationwide Population-Based Study in Korea

Population-based data on drug-resistant epilepsy (DRE) are lacking. This retrospective study aimed to determine the prevalence and incidence of pediatric epilepsy and DRE in South Korea using health insurance claims data from the Health Insurance Review and Assessment Service (2013-2022). Epilepsy and DRE prevalence and incidence in children <18 years old were estimated over time and by age and sex. Results showed that the age-standardized prevalence and incidence rates of epilepsy increased. The age-standardized prevalence rate of DRE increased, while the age-standardized incidence rate remained unchanged. The standardized prevalence rate of DRE was 0.26 per 1000 persons, and the average standardized incidence rate of DRE was 0.06 per 1000 persons. The prevalence rate of DRE gradually increased with age, with age 0 demonstrating the highest incidence rate. The prevalence of generalized DRE was the highest across all ages, and incidence was the highest at 0 years. Conversely, the incidence of focal DRE did not change with age. Our study revealed a stable incidence rate of DRE in Korea, despite increased prevalence. DRE incidence was the highest in the first year of life, with the generalized type being the most prevalent.

Pediatric Extracorporeal Membrane Oxygenation in Korea: A Multicenter Retrospective Study on Utilization and Outcomes Spanning Over a Decade

BACKGROUND

Over the last decade, extracorporeal membrane oxygenation (ECMO) use in critically ill children has increased and is associated with favorable outcomes. Our study aims to evaluate the current status of pediatric ECMO in Korea, with a specific focus on its volume and changes in survival rates based on diagnostic indications.

METHODS

This multicenter study retrospectively analyzed the indications and outcomes of pediatric ECMO over 10 years in patients at 14 hospitals in Korea from January 2012 to December 2021. Four diagnostic categories (neonatal respiratory, pediatric respiratory, post-cardiotomy, and cardiac-medical) and trends were compared between periods 1 (2012-2016) and 2 (2017-2021).

RESULTS

Overall, 1065 ECMO runs were performed on 1032 patients, with the annual number of cases remaining unchanged over the 10 years. ECMO was most frequently used for post-cardiotomy (42.4%), cardiac-medical (31.8%), pediatric respiratory (17.5%), and neonatal respiratory (8.2%) cases. A 3.7% increase and 6.1% decrease in pediatric respiratory and post-cardiotomy cases, respectively, were noted between periods 1 and 2. Among the four groups, the cardiac-medical group had the highest survival rate (51.2%), followed by the pediatric respiratory (46.4%), post-cardiotomy (36.5%), and neonatal respiratory (29.4%) groups. A consistent improvement was noted in patient survival over the 10 years, with a significant increase between the two periods from 38.2% to 47.1% (P = 0.004). Improvement in survival was evident in post-cardiotomy cases (30-45%, P = 0.002). Significant associations with mortality were observed in neonates, patients requiring dialysis, and those treated with extracorporeal cardiopulmonary resuscitation (P < 0.001). In pediatric respiratory ECMO, immunocompromised patients also showed a significant correlation with mortality (P < 0.001).

CONCLUSION

Pediatric ECMO demonstrated a steady increase in overall survival in Korea; however, further efforts are needed since the outcomes remain suboptimal compared with global outcomes.

Factors Associated with Spontaneous Preterm Birth after Ultrasound-Indicated Cerclage

Ultrasound-indicated cerclage (UIC) is recommended to prevent spontaneous preterm birth (sPTB) in women with a short cervix at mid-trimester and a history of PTB. We assessed the factors related to sPTB after UIC and determined the corresponding risks. This retrospective cohort study was conducted at a university hospital. UIC was performed between 15 and 26 weeks of gestation in women with a cervical length of <2.5 cm. Univariate and multivariate analyses were used to examine factors associated with sPTB after UIC. An earlier gestational age and shorter cervical length at UIC were associated with sPTB after UIC. While PTB history was not associated with an increased risk of sPTB, it did increase the risk of repeat cerclage after UIC. Higher levels of preoperative serum inflammatory markers and obesity significantly increased the risk of sPTB after UIC. These findings provide helpful guidance for patient counseling and management in predicting the delivery timing after UIC in women with a short cervix in the mid-trimester.

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.

Evaluation of Morbidities and Complications of Neonatal İntensive Care Unit Patients with Respiratory Disorders at Different Gestational Ages

OBJECTIVE

Respiratory distress presented within the first few days of life is life-threatening and common problem in the neonatal period. The aim of this study is to estimate (1) the incidence of respiratory diseases in newborns and related mortality; (2) the relationship between acute neonatal respiratory disorders rates and gestational age, birth weight, and gender; and (3) the incidence of complications associated with respiratory disturbances.

STUDY DESIGN

Only inborn patients with gestational age between 23^0/7 and 41^6/7 weeks having respiratory distress were included in the study. The data were collected from the medical records and gestational age was based on the menstrual dating.

RESULTS

There were 8,474 live births between January 1, 2013, and June 30, 2013, in our hospital. A total of 1,367 newborns were hospitalized and oxygen therapy was applied in 903 of them because of respiratory distress. An acute respiratory disorder was found to be in 10.6% (903/8,474) among all live births. Mortality was 0.76% (66/8,474). The incidence of respiratory distress syndrome was 2.8% (n = 242). The occurrence of transient tachypnea of newborn was 3.1% (n = 270). Meconium aspiration syndrome, pneumonia, congenital diaphragmatic hernia, and pulmonary maladaptation and primary persistent pulmonary hypertension rates were 0.1, 0.7, 2.2, and 0%, respectively. Overall, 553 (61%) of the 903 newborns having respiratory diseases had complications. The occurrence of necrotizing enterocolitis, patent ductus arteriosus, bronchopulmonary dysplasia, intraventricular hemorrhage and air leak was 6.8, 19.8, 4.7, 24.9, and 5%, respectively.

CONCLUSION

This study offers an epidemiological perspective for respiratory disorders from a single-center level-III neonatal intensive care unit. Although number of births, premature newborns, extremely low birth weight/very low birth weight infants, and complicated pregnancies increase in years, decreasing rates of mortality and complications are very promising. As perinatal and neonatal cares are getting better in every day, we think that more promising results can be achieved over the coming years.

KEY POINTS

· Respiratory distress in the newborn is life-threatening.. · Pulmonary or extrapulmonary diseases may be underlying cause.. · More promising results can be achieved over the coming years with advanced care..

National cohort of infants born before 24 gestational weeks showed increased survival rates but no improvement in neonatal morbidity

AIM

To describe survival and neonatal morbidities in infants born before 24 weeks of gestation during a 12-year period.

METHODS

Data were retrieved from national registries and validated in medical files of infants born before 24 weeks of gestation 2007-2018 in Sweden. Temporal changes were evaluated.

RESULTS

In 2007-2018, 282 live births were recorded at 22 weeks and 460 at 23 weeks of gestation. Survival to discharge from hospital of infants born alive at 22 and 23 weeks increased from 20% to 38% (p = 0.006) and from 45% to 67% (p < 0.001) respectively. Caesarean section increased from 12% to 22% (p = 0.038) for infants born at 22 weeks. Neonatal morbidity rates in infants alive at 40 weeks of postmenstrual age (n = 399) were unchanged except for an increase in necrotising enterocolitis from 0 to 33% (p = 0.017) in infants born at 22 weeks of gestation. Bronchopulmonary dysplasia was more common in boys than girls, 90% versus 82% (p = 0.044). The number of infants surviving to 40 weeks doubled over time.

CONCLUSION

Increased survival of infants born before 24 weeks of gestation resulted in increasing numbers of very immature infants with severe neonatal morbidities likely to have a negative impact on long-term outcome.

Serial Short-Term Outcomes of Very-Low-Birth-Weight Infants in the Korean Neonatal Network From 2013 to 2020

BACKGROUND

We aimed to determine the current survival rate and short-term outcomes of very-low-birth-weight infants (VLBWIs) in Korea, as well as whether the survival rate and short-term outcomes have improved over time since 2013, which was when the Korean Neonatal Network (KNN) was launched.

METHODS

This study used data from the annual reports of the KNN from 2013 to 2020. A total of 16,351 VLBWIs born at gestational age (GA) ≥ 22 weeks between January 1, 2013, and December 31, 2020, and who were registered in the KNN were enrolled. Serial outcomes were analyzed according to era (2013-14, 2015-16, 2017-18, and 2019-20).

RESULTS

More mothers delivered by cesarean section, had diabetes or hypertension during their pregnancy, and received antenatal steroids when analyzed by era. Fewer infants were intubated at birth and had air leaks when analyzed by era. The overall survival rate of VLBWIs between 2013 and 2020 was 87%. The rate of respiratory distress syndrome was 77% and that of bronchopulmonary dysplasia was 32% between 2013 and 2020. The rates of intraventricular hemorrhage (grade ≥ 3), periventricular leukomalacia, and sepsis decreased over time. The survival rate of infants with a GA of 26 weeks has improved serially according to era.

CONCLUSION

Since the launch of the KNN in 2013, the survival rates of infants with GA 26 weeks and short-term outcomes have improved, which implies a quality improvement in antenatal and delivery room care. Further studies on the long-term neurodevelopmental outcomes of these KNN registrants are warranted.

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.

Short term outcomes of extremely low birth weight infants from a multicenter cohort study in Guangdong of China

With the increase in extremely low birth weight (ELBW) infants, their outcome attracted worldwide attention. However, in China, the related studies are rare. The hospitalized records of ELBW infants discharged from twenty-six neonatal intensive care units in Guangdong Province of China during 2008-2017 were analyzed. A total of 2575 ELBW infants were enrolled and the overall survival rate was 55.11%. From 2008 to 2017, the number of ELBW infants increased rapidly from 91 to 466, and the survival rate improved steadily from 41.76% to 62.02%. Increased survival is closely related to birth weight (BW), regional economic development, and specialized hospital. The incidence of complications was neonatal respiratory distress syndrome (85.2%), oxygen dependency at 28 days (63.7%), retinopathy of prematurity (39.3%), intraventricular hemorrhage (29.4%), necrotizing enterocolitis (12.0%), and periventricular leukomalacia (8.0%). Among the 1156 nonsurvivors, 90.0% of infants died during the neonatal period (≤ 28 days). A total of 768 ELBW infants died after treatment withdrawal, for reasons of economic and/or poor outcome. The number of ELBW infants is increasing in Guangdong Province of China, and the overall survival rate is improving steadily.

Association among postpartum posttraumatic stress disorder, family coping, neurodevelopment, and language development in high-risk infants: a retrospective study

BACKGROUND

A high-risk infant (HRI) is a child whose fetal, neonatal, and infant development is impacted by adverse factors that may cause cognitive, sensory, behavioral, or language defects. The complex situation in the treatment process is a continuous challenge and stressor for parents. If parents fail to take appropriate coping styles, it will have an adverse impact on the health of parents and the growth and development of children. The purpose of this study was to explore the impact of clinical characteristics, postpartum posttraumatic stress disorder (PTSD), and family coping on the neurodevelopment and language development of HRIs as a reference for targeted intervention.

METHODS

This study retrospectively recruited 211 children who were hospitalized in the neonatal intensive care unit (NICU) of Suzhou Kowloon Hospital from January 2018 to December 2021. HRI and their mother were interviewed by telephone with general information questionnaire, Perinatal Post-traumatic Stress Disorder Questionnaire, medical coping modes questionnaire, Bayley Scales of Infant Development the Early Language Milestone Scale to investigate HRI and their mothers; Logistic regression was used to analyze the relationship between HRI mothers' emotions and family coping with neurodevelopment and language development.

RESULTS

The neurodevelopmental scores of HRIs differed according to gestational week of delivery, birth weight, and disease diagnosis. The language development scores of HRIs differed according to gestational week of delivery, birth weight, disease diagnosis, and maternal education. Multiple stepwise regression analysis showed that the neurodevelopmental scores were affected by gestational week of delivery, postpartum PTSD score, and family coping. Logistic regression analysis showed that the language development scores were affected by maternal education and neurodevelopmental level. The correlation analysis showed that the postpartum PTSD scores were negatively correlated with family coping, neurodevelopment, and language development, and that family coping was positively correlated with the neurodevelopment and language development scores (P<0.05).

CONCLUSIONS

The neurodevelopment and language development of HRIs were affected by the gestational week of delivery, maternal education, the child's birth weight, and disease diagnosis. NICU wards can promote the healthy development of HRIs by providing mothers with targeted health education concerning the child's condition, postpartum PTSD, and family coping strategies.

Dose completion of antenatal corticosteroids and neonatal outcomes in non-small-for-gestational age or small-for-gestational age very-low-birthweight infants: A Korean population-based cohort study

BACKGROUND

The protective effect of antenatal corticosteroids (ACS) in preterm infants has been well established but it remains unclear in growth-restricted fetuses. Furthermore, a substantial number of pregnant women receive only incomplete ACS treatment because of late presentation or imminent delivery at arrival to the delivery site. How this affects neonatal outcomes in small for gestational age (SGA) infants is not rigorously described. We evaluated the influence of ACS completion on in-hospital neonatal outcomes in very low birthweight (VLBW) infants, depending on appropriately or inappropriately grown singletons.

METHODS

Electronic data were retrieved from the Korean Neonatal Network database between 2013 and 2017. We assessed perinatal and neonatal characteristics and neonatal mortality and morbidities. Multivariable logistic regression analyses were performed to evaluate neonatal outcome variables influenced by an incomplete as compared to a complete course of ACS in non-SGA and SGA infants.

RESULTS

In total, 4441 VLBW infants were included in the study. Complete ACS treatment significantly reduced the risk for death before 28 days of life [odds ratio (OR) = 0.525, 95% confidence interval (CI) = 0.414-0.666], death before neonatal intensive care unit discharge (OR = 0.606, 95% CI = 0.489-0.750), respiratory distress syndrome (OR = 0.634, 95% CI = 0.507-0.793), severe intraventricular hemorrhage (OR = 0.539, 95% CI = 0.424-0.684)], and necrotizing enterocolitis (OR = 0.720, 95% CI = 0.561-0.924) in non-SGA infants. ACS completion did not change the risk for neonatal outcomes in SGA infants.

CONCLUSIONS

This study suggests that a complete course of ACS has a favorable effect on several neonatal outcomes in non-SGA VLBW infants. There were no significant differences between the complete exposure and incomplete exposure group in SGA infants.

Cognitive and Behavioral Outcomes of School-aged Children Born Extremely Preterm: a Korean Single-center Study with Long-term Follow-up

BACKGROUND

School-aged children born very preterm have been suggested to have worse cognitive and behavioral outcomes than children born full-term. Executive function (EF) is a higher level of cognitive function related to academic achievement. The present study aimed to evaluate the cognitive (including EF) and behavioral outcomes of Korean children born extremely preterm (EP) and to analyze any biological or socioeconomic risk factors for poor cognitive outcomes in this population.

METHODS

A total of 71 infants weighing < 1,000 g at birth or born before 30 weeks of gestation (EP group) who were admitted to the neonatal intensive care unit from 2008 to 2009 were included in this study and compared with 40 term-birth controls. The Korean Wechsler Intelligence Scale for Children-Fourth Edition, Advanced Test of Attention (ATA), Stroop test, Children's Color Trails Test (CCTT), and Wisconsin Card Sorting Test (WCST) were used. Additionally, the Korean Child Behavior Checklist (K-CBCL) and Korean ADHD Rating Scale (K-ARS) were completed. Perinatal and demographic data were collected and analyzed.

RESULTS

The mean full-scale intelligence quotient (FSIQ) score in the EP group was significantly lower than that of the term control group (89.1 ± 18.3 vs. 107.1 ± 12.7; P < 0.001). In the EP group, 26 (37%) children had an FSIQ score below 85, compared to only one child (3%) in the control group. Furthermore, the EP group showed significantly worse EF test results (ATA, Stroop test, CCTT, WCST). Except for the higher social immaturity subscore in the EP group, the K-CBCL and K-ARS scores were not different between the two groups. EP children who received laser treatment for retinopathy of prematurity (ROP) had an 8.8-fold increased risk of a low FSIQ score, and a 1-point increase in the discharge weight Z-score decreased the risk of a low FSIQ score by approximately half in this EP cohort.

CONCLUSION

This is the first Korean study to investigate the cognitive and behavioral outcomes of school-aged children born EP. In the study cohort, EP children exhibited significantly lower FSIQ scores and EF than their full-term peers, and 37% of them had cognitive problems. Nonetheless, except for social immaturity, the behavioral problems were not different in EP children. Severe ROP and low discharge weight Z-score were identified as independent risk factors for low FSIQ score after adjusting for birth weight.

Survival and Morbidities in Infants with Birth Weight Less than 500 g: a Nationwide Cohort Study

BACKGROUND

This study aimed to investigate the survival and morbidities of infants in the Korean Neonatal Network (KNN) with birth weight (BW) < 500 g.

METHODS

The demographic and clinical data of 208 live-born infants with a BW < 500 g at a gestational age of ≥ 22 weeks who were treated in the neonatal intensive care units of the KNN between 2013 and 2017 were reviewed.

RESULTS

The survival rate of the infants was 28%, with a median gestational age and BW of 243/7 weeks (range, 220/7-336/7) and 440 g (range, 220-499), respectively. Multivariable Cox proportional hazards analysis demonstrated that survival to discharge was associated with longer gestation, higher BW, female sex, singleton gestation, use of any antenatal corticosteroids, and higher Apgar scores at 5 minutes. The overall survival rates were significantly different between the BW categories of < 400 g and 400-499 g. However, there was no significant difference in the incidence of any morbidity between the BW groups. Half of the deaths of infants with BW < 500 g occurred within a week of life, mainly due to cardiopulmonary and neurologic causes. The major causes of death in infants after 1 week of age were infection and gastrointestinal disease. Among the surviving infants, 79% had moderate to severe bronchopulmonary dysplasia, 21% underwent surgical ligation of patent ductus arteriosus, 12% had severe intraventricular hemorrhage (grade III-IV), 38% had sepsis, 9% had necrotizing enterocolitis (stage ≥ 2), and 47% underwent laser treatment for retinopathy of prematurity. The median length of hospital stay was 132 days (range, 69-291), and 53% required assistive devices at discharge.

CONCLUSION

Despite recent advances in neonatal intensive care, the survival and morbidity rates of infants with BW < 500 g need further improvement.

Neonatal Outcomes according to the Latent Period from Membrane Rupture to Delivery among Extremely Preterm Infants Exposed to Preterm Premature Rupture of Membrane: a Nationwide Cohort Study

BACKGROUND

In accordance with the guidelines for the expectant management of women exposed to previable preterm premature rupture of membrane, we compared neonatal outcomes according to the latent period from membrane rupture to delivery among extremely preterm infants exposed to maternal preterm premature rupture of membrane using the Korean Neonatal Network database.

METHODS

Of the 3,305 extremely preterm infants born at 23-27 weeks' gestation between 2014 and 2017 who were registered in the Korean Neonatal Network, 1,464 infants were born to pregnant women who were exposed to preterm premature rupture of membrane. The short latency group was defined as infants born with a latent period between membrane rupture and delivery < 7 days (n = 450), whereas the prolonged latency group was defined as infants born with a latent period of ≥ 7 days (n = 434). Using well-established risk factors for adverse short-term outcomes, multivariate logistic regression analysis was performed to assess a prolonged latent period in preterm premature rupture of membrane as an independent risk factor for neonatal outcomes in extremely preterm infants exposed to preterm premature rupture of membrane.

RESULTS

The mean gestational age at membrane rupture in the prolonged latency group was significantly lower than that in the short latency group (22.7 ± 2.5 vs. 25.4 ± 1.3 weeks, P < 0.001). Nevertheless, the mean gestational age at delivery and birth weight were not significantly different between the two groups. The incidence of oligohydramnios and histologic chorioamnionitis in the prolonged latency group was significantly higher than that in the short latency group (38.7 [155/401] vs. 26.1 [105/403], 69.8 [270/384] vs. 61.0 [242/397], respectively, P < 0.05). The survival rate in the prolonged latency group did not differ from that in the short latency group (71.2 [309/434] vs. 73.3 [330/450], P = 0.478). Although the prolonged latency group was not associated with mortality during hospitalization in the multivariate logistic regression analysis, the prolonged latency group's early pulmonary hypertension and bronchopulmonary dysplasia rates were increased by 1.8 and 1.5 times, respectively.

CONCLUSION

A prolonged latent period of 7 days or more does not affect the survival rate but increases the risk of bronchopulmonary dysplasia occurrence among extremely preterm infants who are exposed to maternal preterm premature rupture of membrane.

Predictors of cerclage failure in singleton pregnancies with a history of preterm birth and a sonographic short cervix

OBJECTIVE

To identify predictors of ultrasound-indicated cerclage failure in singleton pregnancies for preventing extremely preterm birth.

METHODS

A retrospective cohort study included 96 singleton pregnancies with ultrasound-indicated McDonald cerclage in women with previous preterm birth (PTB) and cervical shortening. Descriptive statistics were calculated at baseline and logistic regression analyses were performed to identify the factors associated with cerclage failure.

RESULTS

In all, 28 (29%) of the women had a preterm delivery at before 28 weeks. Multivariate analysis identified cervical dilatation, non-cephalic presentation, and platelet-lymphocyte ratio (PLR) as independent predictors of cerclage failure (odds ratio [OR] 3.12, 95% CI [confidence interval] 1.01-9.66; OR 5.81, 95% CI 1.04-32.53; OR 1.02, 95% CI 1.01-1.03, respectively). The efficacy of these predictors was evaluated using a receiver operating characteristics curve. The area under the curve was 0.87 (95% CI 0.78-0.96, P < 0.001) with a sensitivity of 78.6% and specificity of 88.2%.

CONCLUSION

Our findings indicated that cervical dilatation, fetal presentation, and PLR were valuable predictors of cerclage failure in singleton pregnancies with a history of PTB and a sonographic short cervix. The results can be potentially used to assess the prognosis of patients after cerclage and alert clinicians to consider enhanced surveillance and administration of individuals at an increased risk.

Development of the Parental Questionnaire for Cerebral Visual Impairment in Children Younger than 72 Months

Background and Purpose

Cerebral visual impairment (CVI) is an underdiagnosed condition in children, and its assessment tools have focused on older children. We aimed to develop a parental questionnaire for cerebral visual impairment (PQCVI) for screening CVI in young children.

Methods

The PQCVI comprised 23 questions based on a modified version of Houliston and Dutton's questionnaire for older children. The PQCVI with neurocognitive function tests was applied to 201 child-parent pairs with typically developing children younger than 72 months (age 32.4±20.1 months, mean±standard deviation). The children were classified into six age groups. The normative data, cutoff scores, and internal reliability were assessed and item analysis was performed. We referred to the total score for all questions as the cerebral visual function (CVF) score.

Results

The normative data showed that the CVF score and the scores corresponding to ventral-stream and dorsal-stream visual functions plausibly increased with age. The scores rapidly reached 90% of their maximum values up to the age of 36 months, after which they increased slowly. Cronbach's alpha for all questions across all age groups was 0.97, showing excellent consistency. The item difficulty and item discrimination coefficients showed that the questions were generally adequate for this age stage.

Conclusions

The PQCVI items produced reliable responses in children younger than 72 months. The rapid increase in scores before the age of 3 years supports the importance of early identification of CVI. Following additional clinical verification, the PQCVI may be useful for CVI screening.

The short-term mortality and morbidity of very low birth weight infants with trisomy 18 or trisomy 13 in Japan

Trisomy 18 (T18) and trisomy 13 (T13) are major concerns in prenatal genetic testing due to their poor prognosis; very low birth weight (VLBW) is also a concern in neonatology. The aim of this study was to investigate the mortality and morbidity of VLBW infants diagnosed with T18/T13 in Japan, compared with those with no birth defects (BD-). Maternal and neonatal data were collected prospectively from infants weighing <1501 g and were admitted to centers of the Neonatal Research Network of Japan during 2003 to 2016. Among 60,136 infants, 563 and 60 was diagnosed with T18 and T13, respectively. Although the age of mothers of infants with T18/T13 was higher, the frequency of maternal complications was lower than those with BD-. With maternal and neonatal characteristic adjustments, T18/T13 had a higher incidence of each morbidity when compared with BD-. Mortality rates in the NICU were 70, 77, and 5.8% for T18, T13, and BD-, respectively, while the survival discharge rates of T18 and T13 were 29.5 and 23.3%, respectively, which was significantly higher than previous reports. This was the first nationwide survey for VLBW infants with T18/T13 in Japan; this novel data will be relevant and useful for prenatal genetic counseling and perinatal management. Although T18/T13 were considered to be fatal in the past, with proper epidemiological information, discussions with affected families, and compassionate patient care, the mortality rate of T18/T13 can be improved.

Pulmonary Surfactant Replacement Therapy for Respiratory Distress Syndrome in Neonates: a Nationwide Epidemiological Study in Korea

BACKGROUND

Pulmonary surfactant (PS) replacement therapy, as a safe and effective treatment for respiratory distress syndrome (RDS) may have further increased with the extended insurance coverage since 2011 in Korea. Thus, this study aimed to investigate the epidemiologic data of PS replacement therapy for RDS in Korea and to analyze the complications associated with RDS.

METHODS

We included 19,442 infants who were treated with PS and diagnosed with RDS (International Classification of Diseases-10 codes: P22.0) between 2014 and 2018 from the Health Insurance Review and Assessment database. Birth certificate data from Statistics Korea were used to estimate the incidence of RDS.

RESULTS

The average incidence of RDS within the study period was 0.99% among live births. Repeated doses of PS were administered to 1,688 infants (8.7%), ranging from 2 doses in 929 infants (4.8%) to 9 doses in 1 infant (0.01%). The incidence of RDS in term infants markedly increased over 5 years from 0.2% to 0.34%. The incidence was similarly increased among the preterm infants. The RDS mortality rate was 6.3% and showed a decreasing trend according to year. The mortality rate was significantly higher in the lower gestational age group. A decreasing trend was observed in the incidence of the complications, such as patent ductus arteriosus, intraventricular hemorrhage, and bronchopulmonary dysplasia, except for pneumothorax in term infants. The complications were also higher in the lower gestational age group and the lower birth weight group. However, pneumothorax was the most frequent complication in the term infant group and in infants with birth weight ≥ 2,500 g.

CONCLUSION

Advancements in neonatal care and extended insurance coverage have increased the use of PS replacement therapy for RDS. This, in turn, decreased neonatal mortality and the incidence of the associated complications. The appropriate therapeutic strategy for RDS should be decided according to the gestational age and lung pathology.

Incidence, Long-Term Visual Outcomes, and Mortality in Retinopathy of Prematurity in Korea: A Nationwide Population-Based Study

Purpose

To evaluate the incidence, visual prognosis, and mortality in retinopathy of prematurity (ROP) in Korea.

Methods

We used the National Health Insurance and the Korean Disability Registry database, which covers the entire newborn population in 2006 to 2014 and includes information on all newborns diagnosed with ROP until 2016. Using these databases, we evaluated the incidence, rate of visual impairment (VI), and mortality in patients with ROP according to the birth weight categories and treatment modalities.

Results

The ROP incidence per 1000 newborns was 1.99, which broke down into 317.14 in the very low birth weight (VLBW) less than 1500 g population, 25.45 in the 1500 to 2499 g population, and 0.29 in the 2500 g or greater population. When assessed at age 10, the VI rate was 2.2 per 100 person-years, which was highest at 4.5 per 100 person-years in the VLBW population compared with the population in other birth weight categories. Among treated cases, the proportion of VI in patients undergoing laser photocoagulation or cryotherapy was 1.6% (42/2595), which was lower than the 2.9% (2/68) of patients treated with anti-vascular endothelial growth factor injection, and 32.2% (82/255) of patients undergoing vitrectomy or scleral buckling. The mortality rate was 4.8 per 1000 person-years, which was highest in the VLBW population, but similar across treatment modalities.

Conclusions

The ROP incidence in Korea was approximately 1 in 500 among all newborns, and 1 in 3 in the VLBW population. As the first nationwide population-based study of long-term visual prognosis in ROP, we report the higher VI rate in ROP than previously determined in other studies. Differences in visual outcomes and comparable mortality risks between treatment modalities require further verification.

International Perspectives: Implementation of the Korean Neonatal Network

Although there has been a marked increase in the number of NICUs in Korea, the gap in quality improvement has remained a national focus. The Korean Neonatal Network (KNN) was established in 2013 by the Korean Society of Neonatology with support from the Korea Centers for Disease Control and Prevention, with the aim of improving neonatal outcomes by offering data-driven interactive tools to all participating NICUs. Approximately 2,000 very-low-birthweight (VLBW) infants from 70 participating hospital NICUs are registered annually in the KNN, with a total of over 12,000 to date. In addition to providing a national registry of VLBW infants, this unique system also leads to an infrastructure for quality improvement in neonatal care, which in turn has an effect on the development of evidence-based neonatal medicine in Korea. Furthermore, it is encouraging that the KNN plans to develop tools to facilitate multicenter clinical trials and to join the global international network for international collaboration.

Risk factors for fungal infection in extremely low birthweight infants registered in the Korean neonatal network from 2013 to 2015: Male sex and hypotension

BACKGROUND

In Korea, improvement in the survival rates of extremely low birthweight (<1,000 g) infants has led to neonatal infection, especially fungal infection (FI), in the neonatal intensive care unit. The purpose of this study was to determine the risk factors for FI by analyzing the incidence of FI in extremely low birthweight infants in Korea.

METHODS

Data from 5,320 very low birthweight (<1,500 g) infants registered from 2013 to 2015 in the Korean Neonatal Network were analyzed. The infants were divided into two groups based on the presence or absence of FI.

RESULTS

Among infants, 1,524 with gestational ages of <27 weeks and birthweights of <1,000 g were included. The incidence of FI was 7.3% (111/1,524) and mortality of the infants with FI was 40% (44/111). The mean gestational age of infants with FI was 24.8 ± 1.0 weeks, which was significantly lower than those without FI. After logistic regression, being male, and having hypotension within 7 days of birth were independent risk factors for FI. Moreover, hypotension was strongly associated with mortality in FI. Adverse outcomes such as severe bronchopulmonary dysplasia, bacteremia, and abnormal hearing test occurred more frequently in infants with FI than non-FI.

CONCLUSIONS

As male sex and hypotension within 7 days of birth increased the risk of developing FI in infants with gestational ages of <27 weeks and birthweights of <1,000 g, preventive strategies to reduce the incidence of FI are required for infants with risk factors for the development of FI.

Effect of red blood cell transfusion on short-term outcomes in very low birth weight infants

BACKGROUND

Red blood cell (RBC) transfusion improves cardiorespiratory status of preterm infants by increasing circulating hemoglobin, improving tissue oxygenation, and reducing cardiac output. However, RBC transfusion itself has also been suggested to negatively affect short-term outcomes such as intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and necrotizing enterocolitis (NEC) in premature infants.

PURPOSE

This study aimed to analyze the relationship between RBC transfusion and short-term outcomes in very low birth weight (VLBW) infants (birth weight, <1,500 g).

METHODS

We retrospectively reviewed the medical records of VLBW infants admitted to the Soonchunhyang University Bucheon Hospital between October 2010 and December 2017. Infants who died during hospitalization were excluded. The infants were divided into 2 groups according to RBC transfusion status. We investigated the relationship between RBC transfusion and short-term outcomes including BPD, ROP, NEC, and IVH.

RESULTS

Of the 250 enrolled VLBW infants, 109 (43.6%) underwent transfusion. Univariate analysis revealed that all shortterm outcomes except early-onset sepsis and patent ductus arteriosus were associated with RBC transfusion. In multivariate analysis adjusted for gestational age, birth weight and Apgar score at 1 minute, RBC transfusion was significantly correlated with BPD (odds ratio [OR], 5.42; P<0.001) and NEC (OR, 3.40; P= 0.009).

CONCLUSION

RBC transfusion is significantly associated with adverse clinical outcomes such as NEC and BPD in VLBW infants. Careful consideration of the patient's clinical condition and appropriate guidelines is required before administration of RBC transfusions.

Comparison of Acute Abdominal Surgical Outcomes of Extremely-Low-Birth-Weight Neonates according to Differential Diagnosis

BACKGROUND

Improvements in perinatal intensive care have improved survival of extremely-low-birth-weight (ELBW) neonates, although the risk of acute abdomen has increased. The differential diagnosis resulting in abdominal surgery can be categorized into necrotizing enterocolitis (NEC), spontaneous intestinal perforation (SIP), meconium-related ileus (MRI), and meconium non-related ileus (MNRI). The purpose of this study was to review our experience with abdominal surgery for ELBW neonates, and to evaluate characteristics and prognosis according to the differential diagnosis.

METHODS

Medical records of ELBW neonates treated between 2003 and 2015 were retrospectively reviewed.

RESULTS

Of 805 ELBW neonates, 65 (8.1%) received abdominal surgery. The numbers of cases by disease category were 29 for NEC, 18 for SIP, 13 for MRI, and 5 for MNRI. Ostoma formation was performed in 61 (93.8%) patients; primary anastomosis without ostoma was performed in 4 (6.2%). All patients without ostoma formation experienced re-perforation of the anastomosis site. Seven patients had 30-day postoperative mortality (6 had NEC). Long-term survival of the surgical and non-surgical groups was not statistically different. NEC was a poor prognostic factor for survival outcome (P = 0.033).

CONCLUSION

Abdominal surgery for ELBW neonates is feasible. Ostoma formation can lead to reduced complications compared to primary anastomosis.

SURVIVAL UNTIL DISCHARGE OF VERY-LOW-BIRTH-WEIGHT INFANTS IN TWO CROATIAN PERINATAL CARE REGIONS: A RETROSPECTIVE COHORT STUDY OF TIME AND CAUSE OF DEATH

We investigated mortality, causes, timing and risk factors for death until hospital discharge in very-low-birth-weight (VLBW) infants born in two Croatian perinatal care regions. This retrospective study included 252 live born VLBW infants. The mortality rate until hospital discharge was 30.5% (77/252). VLBW infants who died had by 4 weeks lower gestational age (GA) than surviving infants (median GA, 25 vs. 29 weeks), lower birth weight (BW) (mean BW, 756.4 vs. 1126.4 g), lower 5-minute Apgar score (median 5 vs. 8) and were more often resuscitated at birth (41.6 vs. 19.4%; p<0.001 all). Infants who survived were more often small-for-gestational age (SGA) (28.0 vs. 15.6%; p=0.04) and more often received continuous-positive-airway-pressure (CPAP) in delivery room (13.1 vs. 2.6%; p=0.01). Multivariate logistic regression revealed that parameters influencing death until hospital discharge were 5-minute Apgar score (OR 0.780, 95% CI 0.648-0.939) and higher Clinical Risk Index for Babies (CRIB) score (OR 1.677, 95% CI 1.456-1.931). ROC analysis showed that CRIB score (AUC 0.927, sensitivity 92.2, specificity 81.1; p<0.001) was the strongest predictor of death until hospital discharge. In infants who died within 12 hours, death was most commonly attributed to immaturity and in those surviving >12 hours to necrotizing enterocolitis.

History of Pulmonary Surfactant Replacement Therapy for Neonatal Respiratory Distress Syndrome in Korea

Neonatal respiratory distress syndrome (RDS) is a disease that is unique to newborn infants. It is caused by a deficiency of pulmonary surfactant (PS), which is usually ready to be activated around the perinatal period. Until RDS was more clearly understood, it was not known why premature infants died from respiratory failure, although pathology revealed hyaline membranes in the alveoli. Surprisingly, the era of PS replacement therapy began only relatively recently. The first clinical trial investigating neonatal RDS was conducted in 1980. Since then, newborn survival has improved dramatically, which has led to significant advances in the field of neonatology. The present comprehensive review addresses PS, from its discovery to the application of artificial PS in newborns with RDS. It also reviews the history of PS in Korea, including its introduction, various commercial products, present and past research, newborn registries, and health insurance issues. Finally, it describes the inception of the Korean Society of Neonatology and future directions of research and treatment.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Survival and Impairment of Extremely Premature Infants: A Meta-analysis

CONTEXT

Survival of infants born at the limit of viability varies between high-income countries.

OBJECTIVE

To summarize the prognosis of survival and risk of impairment for infants born at 22 + 0/7 weeks' to 27 + 6/7 weeks' gestational age (GA) in high-income countries.

DATA SOURCES

We searched 9 databases for cohort studies published between 2000 and 2017 in which researchers reported on survival or neurodevelopmental outcomes.

STUDY SELECTION

GA was based on ultrasound results, the last menstrual period, or a combination of both, and neurodevelopmental outcomes were measured by using the Bayley Scales of Infant Development II or III at 18 to 36 months of age.

DATA EXTRACTION

Two reviewers independently extracted data and assessed the risk of bias and quality of evidence.

RESULTS

Sixty-five studies were included. Mean survival rates increased from near 0% of all births, 7.3% of live births, and 24.1% of infants admitted to intensive care at 22 weeks' GA to 82.1%, 90.1%, and 90.2% at 27 weeks' GA, respectively. For the survivors, the rates of severe impairment decreased from 36.3% to 19.1% for 22 to 24 weeks' GA and from 14.0% to 4.2% for 25 to 27 weeks' GA. The mean chance of survival without impairment for infants born alive increased from 1.2% to 9.3% for 22 to 24 weeks' GA and from 40.6% to 64.2% for 25 to 27 weeks' GA.

LIMITATIONS

The confidence in these estimates ranged from high to very low.

CONCLUSIONS

Survival without impairment was substantially lower for children born at <25 weeks' GA than for those born later.

Continuous amnioinfusion in women with PPROM at periviable gestational ages

Objective: To elucidate the efficacy of continuous amnioinfusion on perinatal outcome in women with preterm premature rupture of membranes (PPROM) at periviable gestational ages.Methods: A database was reviewed to identify women with singleton pregnancies who were admitted to the Japanese Red Cross Nagoya Daiichi Hospital due to PPROM before 26 + 0-week gestation between July 2009 and July 2017.Results: A total of 81 women met the criteria for inclusion in this study including 70 and 11 women with and without amnioinfusion, respectively. The latency period between PPROM and delivery was significantly longer in women who underwent amnioinfusion compared with women without amnioinfusion (median: 13 versus 4 days, p < .001). In the survival analysis, the number of women who remained undelivered was significantly higher in the amnioinfusion group than in the non-amnioinfusion group for each gestational age after PPROM (p < .001). Cox's proportional hazards analysis with stepwise backward selection showed that both white blood cell counts on admission and amnioinfusion finally remained as variables that affected the time interval between PPROM and delivery [hazard ratio (95% confidence interval): 1.12 (1.06-1.18) and 0.34 (0.12-0.98), respectively].Conclusions: Continuous amnioinfusion in women with PPROM at periviable gestational ages resulted in significant prolongation of pregnancy and may help improve neonatal outcomes.

[A single-center study on the incidence and mortality of preterm infants from 2006 to 2016]

OBJECTIVE

To investigate the incidence and mortality rates of preterm infants and the main causes of death.

METHODS

The basic information of preterm infants was collected from their medical records and admission/discharge records to analyze the incidence and mortality rates of preterm infants and the causes of their death.

RESULTS

There were 76 812 neonates born in the Xuzhou Maternal and Child Health Hospital from January 2006 to December 2016, among whom 5 585 (7.27%) were preterm infants. The incidence rate of preterm infants tended to increase over these years (P&lt;0.001). The overall mortality rate was 5.01% (280/5 585), and the mortality rate tended to decrease over these years (P&lt;0.001). The mortality rate increased with the reductions in birth weight and gestational age (P&lt;0.001). The top four causes of death in preterm infants were respiratory distress syndrome (44.3%), severe asphyxia (12.9%), neonatal malformation (4.3%), and pulmonary hemorrhage (2.9%) respectively. With the increase in birth weight, there were significant reductions in the constituent ratios of death due to respiratory distress syndrome and severe asphyxia (P&lt;0.001).

CONCLUSIONS

The incidence rate of preterm infants tended to increase and their mortality rate tended to decrease from 2006 to 2016. The mortality rate of preterm infants is associated with gestational age and birth weight. Respiratory distress syndrome and severe asphyxia are the main causes of death in preterm infants.

[A single-center study on the incidence and mortality of preterm infants from 2006 to 2016]

OBJECTIVE

To investigate the incidence and mortality rates of preterm infants and the main causes of death.

METHODS

The basic information of preterm infants was collected from their medical records and admission/discharge records to analyze the incidence and mortality rates of preterm infants and the causes of their death.

RESULTS

There were 76 812 neonates born in the Xuzhou Maternal and Child Health Hospital from January 2006 to December 2016, among whom 5 585 (7.27%) were preterm infants. The incidence rate of preterm infants tended to increase over these years (P<0.001). The overall mortality rate was 5.01% (280/5 585), and the mortality rate tended to decrease over these years (P<0.001). The mortality rate increased with the reductions in birth weight and gestational age (P<0.001). The top four causes of death in preterm infants were respiratory distress syndrome (44.3%), severe asphyxia (12.9%), neonatal malformation (4.3%), and pulmonary hemorrhage (2.9%) respectively. With the increase in birth weight, there were significant reductions in the constituent ratios of death due to respiratory distress syndrome and severe asphyxia (P<0.001).

CONCLUSIONS

The incidence rate of preterm infants tended to increase and their mortality rate tended to decrease from 2006 to 2016. The mortality rate of preterm infants is associated with gestational age and birth weight. Respiratory distress syndrome and severe asphyxia are the main causes of death in preterm infants.

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

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

The Youngest Survivor with Gestational Age of 21⁵/₇ Weeks

The decision whether or not to resuscitate extremely low gestational age (GA) infants is recommended to be individualized according to antenatal counseling with parents, neonatologists, and obstetricians. A GA of 22⁰/₇-23⁶/₇ weeks is generally considered as the lower end of the range where infants can be candidates for selective resuscitation. Below this lower end of periviable gestation, resuscitation is usually not considered and survivors are rarely reported. To date, the youngest survivor is an infant with a GA of 21⁶/₇ weeks reported in the English medical literature. Here, we report the case of a female infant, the first twin conceived through in vitro fertilization, with a GA of 21⁵/₇ weeks, who was resuscitated initially according to strong parental wishes after antenatal counseling and is still surviving at 43 months of age with fairly good neurodevelopmental outcome.

Recent Changes in End-of-Life Decisions for Newborns in a Korean Hospital

INTRODUCTION

Despite recent advances in neonatal intensive care in Korea, few studies exist on the end-of-life decisions in newborns. In this study, we sought to examine the status of end-of-life decisions in neonates, changes over time, and affecting factors.

METHODS

This is a retrospective study of neonates who died between 2001 and 2015 in the neonatal intensive care unit of Dong-A University Hospital in Busan. The types of end-of-life decisions were divided into active resuscitation, withholding treatment, and withdrawing treatment. The study period was divided into 3 time frames using 5-year intervals to investigate changes over time. To identify the associated factors, we analyzed the demographic and clinical characteristics of the neonates and their parents using the χ² test and independent t test.

RESULTS

Of the neonatal deaths included in the analysis (n = 222), active resuscitation, withholding treatment, and withdrawing treatment groups accounted for 73.4%, 25.2%, and 1.4% of cases, respectively. When comparing changes over time, between period 1 (2001-2005), 2 (2006-2010), and 3 (2011-2015), the proportion of active resuscitation decreased significantly, from 80.9% to 60.8%, while that of nonactive resuscitation increased significantly from 19.1% to 39.2%. The factors associated with end-of-life decisions were the clinical condition of the neonate at the time of death, rather than general characteristics or socioeconomic factors.

CONCLUSIONS

In Korea, changes in the decisions on end-of-life care in neonates are shifting from active resuscitation to nonactive resuscitation based on clinical conditions.

Comparison of the Birth Statistics between Multi-cultural and Korean Families in Korea (2015)

Since 2002, the number of marriages, births, and family members among multi-cultural families (MCFs) has increased. Beginning in 2006, the government initiated a planned management for such families and has implemented the MCF policy basic plan since 2010. In 2015, with multiple socio-economic and medical support initiatives for MCF being available, we analyzed the statistics for several factors related to birth, to determine whether there are significant adverse birth outcomes in MCF. We analyzed the birth data of MCFs in 2015, from Statistics Korea. This study compared the birth data of MCF and Korean families (KF) by geography, neonatal birth weight (BW), gestational age (GA), birth order of the neonates, place of delivery, cohabitation period of parents before the first child, and parental education level. The distribution of BW and the prevalence of low BW (< 2,500 g) or very low BW (< 1,500 g) were similar between both groups. The incidence of preterm birth was lower in the MCF group (6.5% vs. 7.0%, P = 0.015) than in the KF group. In the MCF group, parental education level was lower, and incidence of out-of-hospital births was higher than that of the KF group. Adverse birth outcomes, such as preterm birth and low BW in MCF are similar or better than KF. This study could be a good basis to present the status of MCF birth and newborn care in 2015.

Improvement in the Survival Rates of Very Low Birth Weight Infants after the Establishment of the Korean Neonatal Network: Comparison between the 2000s and 2010s

The survival rate (SR) of very low birth weight infants (VLBWIs) and extremely low birth weight infants (ELBWIs) is a health indicator of neonatal intensive care unit (NICU) outcomes. The Korean Neonatal Network (KNN) was established in 2013, and a system has been launched to manage the registration and quality improvement of VLBWIs. The SR of the VLBWIs significantly increased to 85.7% in the 2010s compared with 83.0% in the 2000s. There was also a significant increase in the SR of the ELBWIs from 66.1% to 70.7%. The equipment, manpower, and assistance systems of NICUs also improved in quantity and quality. In the international comparison of the SRs of VLBWIs, the SRs were 93.8%, 92.2%, 90.2%, 89.4%, 86.4%, 85.1%, and 80.6% in Japan, Australia and New Zealand, Canada, Europe, Korea, Taiwan, and United States, respectively. In conclusion, the SRs of the VLBWIs and ELBWIs improved in the 2010s compared with those in the 2000s in Korea. This improvement is considered to have been related to the role of the KNN built in 2013. However, the latest VLBWI and ELBWI SRs in 2015 are still low compared with those in Japan, Australia and New Zealand, Canada, and Europe. In the future, we must establish and develop the tasks that are presented as future tasks in this review.

Trends in Fetal and Perinatal Mortality in Korea (2009-2014): Comparison with Japan and the United States

Fetal death is an important indicator of national health care. In Korea, the fetal mortality rate is likely to increase due to advanced maternal age and multiple births, but there is limited research in this field. The authors investigated the characteristics of fetal deaths, the annual changes in the fetal mortality rate and the perinatal mortality rate in Korea, and compared them with those in Japan and the United States. Fetal deaths were restricted to those that occurred at 20 weeks of gestation or more. From 2009 to 2014, the overall mean fetal mortality rate was 8.5 per 1,000 live births and fetal deaths in Korea, 7.1 in Japan and 6.0 in the United States. While the birth rate in Korea declined by 2.1% between 2009 and 2014, the decrease in the number of fetal deaths was 34.5%. The fetal mortality rate in Korea declined by 32.9%, from 11.0 in 2009 to 7.4 in 2014, the largest decline among the 3 countries. In addition, rates for receiving prenatal care increased from 53.9% in 2009 to 75.0% in 2014. Perinatal mortality rate I and II were the lowest in Japan, followed by Korea and the United States, and Korea showed the greatest decrease in rate of perinatal mortality rate II. In this study, we identified that the indices of fetal deaths in Korea are improving rapidly. In order to maintain this trend, improvement of perinatal care level and stronger national medical support policies should be maintained continuously.

Factors associated with delivery at or after 28 weeks gestation in women with bulging fetal membranes before 26 weeks gestation

OBJECTIVE

To elucidate the factors that contribute to prolonged pregnancy and promote neonate survival in women with bulging fetal membranes.

METHODS

A database was reviewed to identify women with singleton pregnancies who underwent amniocentesis on admission to determine amniotic fluid neutrophil elastase levels before 26 + 0 weeks gestation between July 2001 and January 2015. Following delivery, the placentas of these patients were examined for histologic chorioamnionitis.

RESULTS

Ninety-seven women delivered before 28 weeks gestation, and 117 women delivered at or after 28 weeks gestation. Rescue cerclage performed via the McDonald procedure (adjusted odds ratio [aOR]: 3.78; 95% confidence interval [CI]: 1.35-11.80) was associated with a higher likelihood of reaching at least 28 weeks gestation before delivery, whereas protruding membranes (aOR: 0.38; 95% CI: 0.18-0.78), elevated amniotic neutrophil elastase levels (≥0.15 μg/ml) (aOR, 0.41; 95% CI: 0.20-0.82) and elevated peripheral C-reactive protein levels (≥0.4 mg/dl) (aOR: 0.34; 95% CI: 0.180.65) were associated with a significantly reduced likelihood of reaching this gestational age before delivery. Among women who underwent rescue cerclage, amniorrhexis was associated with a negative prognosis (aOR: 0.18; 95% CI: 0.05-0.51).

CONCLUSIONS

Intra-amniotic inflammation, protrusion of fetal membranes and amniorrhexis are factors that may prevent pregnancy prolongation. Rescue cerclage improves pregnancy outcomes.