Early-childhood neurodevelopmental outcomes are not improving for infants born at <25 weeks' gestational age

Resource and Service Use after Discharge Among Infants 22-25 Weeks Estimated Gestational Age at the First High-Risk Infant Follow-Up Visit in California

OBJECTIVE

To examine resource and service use after discharge among infants born extraordinarily preterm in California who attended high-risk infant follow-up (HRIF) clinic by 12 months corrected age.

STUDY DESIGN

We included infants born 2010-2017 between 22 + 0/7 and 25 + 6/7 weeks' gestational age in the California Perinatal Quality Care Collaborative and California Perinatal Quality Care Collaborative-California Children's Services HRIF databases. We evaluated rates of hospitalization, surgeries, medications, equipment, medical service and special service use, and referrals. We examined factors associated with receiving ≥ 2 medical services, and ≥ 1 special service.

RESULTS

A total of 3941 of 5284 infants received a HRIF visit by 12 months corrected age. Infants born at earlier gestational ages used more medications, equipment, medical services, and special services and had higher rates of referral to medical and special services at the first HRIF visit. Infants with major morbidity, surgery, caregiver concerns, and mothers with more years of education had higher odds of receiving ≥ 2 medical services. Infants with Black maternal race, younger maternal age, female sex, and discharge from lower level neonatal intensive care units (NICUs) had lower odds of receiving ≥ 2 medical services. Infants with more educated mothers, multiple gestation, major morbidity, surgery, caregiver concerns, and discharge from lower level NICUs had increased odds of receiving a special service.

CONCLUSIONS

Infants born extraordinarily preterm have substantial resource use after discharge. High resource utilization was associated with maternal/sociodemographic factors and expected clinical factors. Early functional and service use information is valuable to parents and underscores the need for NICU providers to appropriately prepare and refer families.

Respiratory Severity Score and Neurodevelopmental Outcomes at Age 3 Years in Extremely Preterm Infants

OBJECTIVE

 We aimed to examine the association between respiratory severity score (RSS; mean airway pressure × fraction of inspired oxygen) and neurodevelopmental outcomes in extremely preterm infants.

STUDY DESIGN

 This was a single-center, retrospective cohort study. We analyzed data from extremely preterm infants who were admitted to the neonatal intensive care unit at Okayama Medical Center between 2010 and 2019. Infants without invasive respiratory management during the first day of life were excluded. The exposure variable was the highest RSS during the first day of life. RSS was categorized into two groups: low (<3.5) and high (≥3.5) RSS. The primary outcome was death or neurodevelopmental impairment at age 3 years, defined as cognitive impairment (developmental quotient <70) or the presence of cerebral palsy. Secondary outcomes were the components of the primary outcome. We conducted robust Poisson regression analyses to investigate the association between RSS category and primary and secondary outcomes, adjusting for perinatal confounders.

RESULTS

 The cohort included 97 infants with neurodevelopmental data, of whom 34 and 63 infants were in the low- and high-RSS categories, respectively. The median (interquartile range) gestational age and birth weight were 26.0 (24.7-26.9) and 25.7 (24.6-26.7) weeks and 761 (584-866) and 806 (618-898) g for infants in the low- and high-RSS categories, respectively. Compared with infants in the low-RSS category, those in the high-RSS category had a greater risk of death or neurodevelopmental impairment at age 3 years (26.3 vs. 42.3%; adjusted risk ratio [RR], 2.0; 95% confidence interval [CI], 1.1-3.5) and neurodevelopmental impairment at age 3 years (17.6 vs. 28.6%; adjusted RR, 2.7; 95% CI, 1.3-5.9).

CONCLUSION

 High RSS (≥3.5) during the first day of life was associated with an increased risk of neurodevelopmental impairment at age 3 years in extremely preterm infants.

KEY POINTS

· RSS is a valuable tool for assessing respiratory failure.. · RSS = Mean airway pressure × fraction of inspired oxygen.. · RSS at age 1 day was associated with neurodevelopment..

Postnatal weight loss and neurodevelopmental outcomes at age 3 years in extremely preterm infants: a cohort study

BACKGROUND

Previous research has suggested a correlation between postnatal maximum weight loss (MWL) and both neonatal mortality and morbidities in extremely preterm infants. However, the relationship between MWL and neurodevelopmental outcomes remains underexplored.

METHODS

In a single-center, retrospective cohort study at Okayama Medical Center, we evaluated data from extremely preterm infants admitted to the neonatal intensive care unit from 2010 to 2020. Infants who died within the first 10 days of life were excluded. MWL in the first 10 days was the main exposure, categorized into three groups: >15%, 5-15%, and < 5%. The primary outcome evaluated was the occurrence of death or neurodevelopmental impairment (NDI) at age 3 years, defined as developmental impairments (developmental quotient [DQ] < 85), cerebral palsy, hearing impairments, or visual impairments. Data analysis involved robust Poisson regression, adjusted for perinatal confounders, with a restricted cubic spline function to examine the dose-response relationship. We also conducted a sensitivity analysis using a DQ of < 70 to define developmental impairment.

RESULTS

Among 135 infants assessed for neurodevelopmental outcomes, 40 were in the > 15% MWL group, 71 in the 5-15% group, and 24 in the < 5% group. Median gestational ages and birth weights were 25.9 weeks and 821 g for > 15% MWL; 26.1 weeks and 818 g for 5-15% MWL; and 26.0 weeks and 734 g for < 5% MWL. Compared with the 5-15% MWL group, the < 5% group exhibited a higher risk of death or NDI at age 3 years (62.8% vs. 80.8%, risk ratio [RR] 1.36, 95% confidence interval [CI] 1.04-1.79) and NDI alone (59.2% vs. 79.2%, RR 1.43, 95% CI 1.06-1.94). Furthermore, higher risks of developmental impairment were also noted in the > 15% (RR 1.32, 95% CI 1.00-1.75) and < 5% (RR 1.46, 95% CI 1.08-1.98) groups. These associations were confirmed by spline analyses. In contrast, the associations between MWL and neurodevelopmental outcomes using a DQ of < 70 were not apparent.

CONCLUSIONS

MWL within the first 10 days of life may be associated with increased risks of NDI and developmental impairments by age 3 years in extremely preterm infants.

A Dose-Limited Dexamethasone and Bubble Continuous Positive Airway Pressure in Ventilation-Dependent Extremely Premature Infants

OBJECTIVE

Dexamethasone has been associated with early extubation and shorter duration of mechanical ventilation in preterm infants. High doses or prolonged courses of dexamethasone may be associated with poor neurodevelopmental outcomes.

STUDY DESIGN

This is an observational cohort study assessing the efficacy of a low-dose short dexamethasone course combined with postextubation bubble continuous positive airway pressure (bCPAP) strategy on rates of successful extubation and reduction of the duration of invasive mechanical ventilation in extremely preterm infants. We compared the short-term outcomes of implementing such strategy on a group of infants with birth weight <750 g to a historical cohort.

RESULTS

Among infants intubated for at least 10 days, median time to extubation from starting the dexamethasone course was 2 days (interquartile range: 1-3). Total duration of intubation was significantly shorter in infants who received dexamethasone compared with the control groups (21 ± 6 vs. 30 ± 10 days, p = 0.03), and although statistically nonsignificant, duration to wean to 21% bCPAP was shorter compared with the control group (48 ± 13 vs. 74 ± 29 days, p = 0.06).

CONCLUSION

A low-dose short dexamethasone course combined with postextubation bCPAP intervention may be associated with successful early extubation and shorter duration of mechanical ventilation.

KEY POINTS

· Noninvasive strategies may not succeed in infants < 750 g birth weight.. · Bubble CPAP has been shown to be associated with reduced complications including chronic lung disease.. · Postnatal dexamethasone therapy may succeed in conjunction with bubble CPAP to reduce reintubation..

Severe brain injury and trends of gestational-age-related neurodevelopmental outcomes in infants born very preterm: A population cohort study

AIM

To investigate the impact of severe neonatal brain injury (SNBI) on gestational age-related trends in neurodevelopmental impairment (NDI) outcome in infants born very preterm.

METHOD

A population-based cohort study recruited 1091 infants born at a gestational age of less than 31 weeks between 2011 and 2020. The trends in neonatal morbidities, mortality, and 24-month NDI severity (no/mild, moderate, severe) by epoch (2011-2015, 2016-2020) and gestational age (22-25 weeks, 26-28 weeks, 29-30 weeks) were determined in infants with and without SNBI inclusion.

RESULTS

There was increased antenatal steroid use and higher maternal education and socioeconomic status over time. The rates of neonatal morbidities and mortality had no temporal changes. Among 825 infants with follow-up, those in the 22 to 25 weeks gestational age group had declining trends in cerebral palsy and severe cognitive impairment, with decreased rates of severe NDI from 19% to 8% across epochs, particularly in those without SNBI (from 16% to 2%). Relative to its occurrence in epoch 2011 to 2015, risk of severe NDI was significantly reduced in epoch 2016 to 2020 (adjusted relative risk 0.39, 95% confidence interval 0.16-0.96) for infants born at 22 to 25 weeks gestational age, and the risk dropped even lower in these infants without SNBI (0.12, 0.02-0.84).

INTERPRETATION

Infants born at 22 to 25 weeks gestational age had decreased rates of severe NDI in the decade between 2011 and 2020, particularly those without SNBI. The improvement might be attributed to better perinatal/neonatal and after-discharge care.

Subventricular zone stem cell niche injury is associated with intestinal perforation in preterm infants and predicts future motor impairment

Brain injury is highly associated with preterm birth. Complications of prematurity, including spontaneous or necrotizing enterocolitis (NEC)-associated intestinal perforations, are linked to lifelong neurologic impairment, yet the mechanisms are poorly understood. Early diagnosis of preterm brain injuries remains a significant challenge. Here, we identified subventricular zone echogenicity (SVE) on cranial ultrasound in preterm infants following intestinal perforations. The development of SVE was significantly associated with motor impairment at 2 years. SVE was replicated in a neonatal mouse model of intestinal perforation. Examination of the murine echogenic subventricular zone (SVZ) revealed NLRP3-inflammasome assembly in multiciliated FoxJ1+ ependymal cells and a loss of the ependymal border in this postnatal stem cell niche. These data suggest a mechanism of preterm brain injury localized to the SVZ that has not been adequately considered. Ultrasound detection of SVE may serve as an early biomarker for neurodevelopmental impairment after inflammatory disease in preterm infants.

Virtual Visits for Developmental Screening in High-Risk Infants

INTRODUCTION

The High-Risk Infant Follow-Up program screens neonatal intensive care unit graduates for developmental delays and refers patients to physical, occupational, or speech therapy. At Kaiser Permanente Downey, the High-Risk Infant Follow-Up program assessed development via video visits during the COVID-19 pandemic. This study compares rates of enrollment in and referral to therapies and California Regional Center services between infants assessed by video visits and those assessed in person.

METHODS

Study participants included infants in the High-Risk Infant Follow-Up program between March 2020 and March 2021 with developmental assessments at adjusted ages 6, 12, and 18 months. Rates of enrollment in services and referral to physical, occupational, and speech therapy and Regional Center services were compared between infants assessed virtually and in person.

RESULTS

There were no significant differences in rates of enrollment or referral to physical, occupational, or speech therapy services or Regional Center services. The rate of referral at any of the 3 visits was 8.6% at in-person visits and 10.9% at virtual visits (p = 0.49). Infants whose first visit was virtual were just as likely to complete all 3 developmental assessments as those whose first visit was in person.

DISCUSSION

The COVID-19 pandemic stay-at-home orders provided a "natural experiment" demonstrating the effectiveness of virtual visits as compared to in-person visits. Although the developmental assessment tool used was not standardized to be used virtually, virtual visits were just as likely to result in referrals to services and did not lead to loss of follow-up.

CONCLUSION

Virtual visits may be useful and convenient for some families, but further study is required.

Change in neurodevelopmental outcomes for extremely premature infants over time: a systematic review and meta-analysis

OBJECTIVE

Survival rates of extremely premature infants are rising, but changes in neurodevelopmental impairment (NDI) rates are unclear. Our objective was to perform a systematic review of intrainstitutional variability of NDI over time.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Ovid MEDLINE, Embase, PubMed, Cochrane Library and Google Scholar.

STUDY SELECTION

Study eligibility: (1) at least two discrete cohorts of infants born <27 weeks' gestation or <1000 g birth weight, (2) one cohort born after 1990 and at least one subsequent cohort of similar gestational age, (3) all cohorts cared for within the same Neonatal Intensive Care Unit(s) (NICU) and (4) neurodevelopmental outcomes at 18-36 months corrected age.

MAIN OUTCOME

Change in NDI rates. Quality, validity and bias were assessed using Grading of Recommendations, Assessment, Development, and Evaluation and Quality in Prognosis Studies guidelines.

RESULTS

Of 203 publications, 15 were eligible, including 13 229 infants. At the first time point, average NDI rate across study groups weighted by sample size was 41.0% (95% CI 34.0% to 48.0%). The average change in NDI between time points was -3.3% (95% CI -8·8% to 2.2%). For each added week of gestation at birth, the rate of NDI declined by 9.7% (95% CI 6.2% to 13.3%). Most studies exhibited moderate-severe bias in at least one domain, especially attrition rates.

CONCLUSIONS

When comparing discrete same-centre cohorts over time, there was no significant change in NDI rates in infants born <27 weeks' gestation or <1000 g. Higher survival rates unaccompanied by improvement in neurodevelopment highlight urgency for renewed focus on the causes of NDI and evidence-based strategies to reduce brain injury.

Parenting Interventions Targeting Behavior for Children Born Preterm or Low Birth Weight: A Systematic Review

OBJECTIVE

To systematically review and summarize the outcomes of parenting interventions designed to improve child and/or parenting behavior for children born preterm and/or low birth weight (LBW).

METHODS

We conducted systematic searches of Embase, Scopus, PubMed, PsycInfo, and CINAHL in September 2021. We identified articles published at any time that describe the outcomes of parenting interventions targeting the child and/or parenting behavior of children born preterm/LBW and their caregivers. Two independent raters assessed the risk of bias using the Revised Cochrane Risk-of-Bias Tool.

RESULTS

Eight hundred sixteen titles and abstracts were screened, followed by 71 full-text articles, resulting in 24 eligible articles reporting on nine interventions with 1,676 participants. Eligible articles had an adequate risk of bias ratings. Sample characteristics, intervention components, and intervention effects were tabulated and described narratively by the intervention type. Preventative and treatment programs demonstrated positive intervention effects on externalizing behavior, parenting stress, and parenting behaviors, with mixed effects on internalizing behavior and emotion regulation. The few studies with longitudinal follow-up found little evidence of effects beyond 6 months postintervention.

CONCLUSION

Behavior problems in children born preterm/LBW may be modifiable, and interventions targeting parenting behavior are promising. However, existing interventions may not produce long-lasting changes and are not designed for children older than four. Existing treatment programs may require adaptation for the neurocognitive, medical, and family needs of children born preterm/LBW (e.g., processing speed deficits, post-traumatic stress). Interventions that account for theories of sustained change may promote long-term effectiveness and the developmental tailoring of parenting skills.

Language Impairment in Children of Mothers with Gestational Diabetes, Preeclampsia, and Preterm Delivery: Current Hypothesis and Potential Underlying Mechanisms : Language Impartment and Pregnancy Complications

Many conditions may impair or delay language development, including socioeconomic status, parent's education, or intrauterine environment. Accordingly, increasing evidence has described that pregnancy complications, including gestational diabetes mellitus (GDM), preeclampsia, and preterm delivery, are associated with the offspring's impaired neurodevelopment. Since language is one of the high brain functions, alterations in this function are another sign of neurodevelopment impairment. How these maternal conditions may generate language impairment has yet to be entirely understood. However, since language development requires adequate structural formation and function/connectivity of the brain, these processes must be affected by alterations in maternal conditions. However, the underlying mechanisms of these structural alterations are largely unknown. This manuscript critically analyzes the literature focused on the risk of developing language impairment in children of mothers with GDM, preeclampsia, and preterm delivery. Furthermore, we highlight potential underlying molecular mechanisms associated with these alterations, such as neuroinflammatory and metabolic and cerebrovascular alterations.

How lung injury and therapeutic oxygen could alter white matter development

Developmental brain injury describes a spectrum of neurological pathologies resulting from either antenatal or perinatal injury. This includes both cognitive and motor defects that affect patients for their entire lives. Developmental brain injury can be caused by a spectrum of conditions including stroke, perinatal hypoxia-ischemia, and intracranial hemorrhage. Additional risk factors have been identified including very low birth weight, mechanical ventilation, and oxygen (O2 ) supplementation. In fact, infants with bronchopulmonary dysplasia, an inflammatory disease associated with disrupted lung development, have been shown to have decreased cerebral white matter and decreased intracranial volumes. Thus, there appears to be a developmental link between the lung, O2 , and the brain that leads to proper myelination. Here, we will discuss what is currently known about the link between O2 and myelination and how scientists are exploring mechanisms through which supplemental O2 and/or lung injury can affect brain development. Consideration of a link between the diseased lung and developing brain will allow clinicians to fine tune their approaches in managing preterm lung disease in order to optimize brain health.

Early neurodevelopmental follow-up in the NICHD neonatal research network: Advancing neonatal care and outcomes, opportunities for the future

At the inception of the Eunice Kennedy Shriver National Institute of Child Health and Development Neonatal Research Network (NRN), provision of care for extremely preterm (EPT) infants was considered experimental. The NRN Follow-up Study Group, initiated in 1993, developed infrastructure with certification processes and standards, allowing the NRN to assess 2-year outcomes for EPT and to provide important metrics for randomized clinical trials. This chapter will review the NRN Follow-up Study Group's contributions to understanding factors related to improved neurodevelopmental, behavioral, and social-emotional outcomes of EPT infants. We will also discuss follow up challenges, including reassessing which outcomes are most meaningful for parents and investigators. Finally, we will explore how outcome studies have informed clinical decisions and ethical considerations, given limitations of prediction of complex later childhood outcomes from early neurodevelopmental findings.

NICU-based stress response and preterm infant neurobehavior: exploring the critical windows for exposure

BACKGROUND

Exposure to maternal stress in utero negatively impacts cognitive and behavioral outcomes of children born at term. The neonatal intensive care unit (NICU) can be stressful for preterm infants during a developmental period corresponding to the third trimester of gestation. It is unknown whether stress in the NICU contributes to adverse neurodevelopment among NICU graduates. The aim was to examine the association between salivary cortisol and early neurodevelopment in preterm infants.

METHODS

We examined the association between cortisol levels during the NICU hospitalization and subsequent performance on the NICU Network Neurobehavioral Scales (NNNS), estimating time-specific associations and considering sex differences.

RESULTS

Eight hundred and forty salivary cortisol levels were measured from 139 infants. Average cortisol levels were inversely associated with NNNS Regulation scores for both male and female infants (β = -0.19; 95% CI: -0.44, -0.02). Critical developmental windows based on postmenstrual age were identified, with cortisol measured <30 weeks PMA positively associated with Habituation and Lethargy scores (β = 0.63-1.04). Critical developmental windows based on chronological age were identified, with cortisol measured in the first week of life inversely associated with Attention score (β = -1.01 for females; -0.93 for males).

CONCLUSIONS

Stress in the NICU at specific developmental time points may impact early preterm infant neurodevelopment.

IMPACT

Stress in the neonatal intensive care unit can impact the neurodevelopmental trajectory of premature infants. The impact of stress is different at different points in development. The impact of stress is sexually dimorphic.

The critical importance of follow-up to school age: Contributions of the NICHD Neonatal Research Network

Follow-up studies are essential for understanding outcomes and informing the care of infants with high risk for medical and developmental consequences because of extreme prematurity or perinatal illness. Studies that extend to school age often identify sequelae that go unrecognized in neonatal or short-term follow-up studies. Many critical neurocognitive, behavioral, functional, and health outcomes are best assessed beginning at school age. The Eunice Kennedy Shriver National Institute of Child Health and Development Neonatal Research Network (NRN) has performed comprehensive school age evaluations of several key trial cohorts. This manuscript summarizes the important contributions of school age follow-up studies in the NRN, both historically and in ongoing research. We describe in detail the clinical questions that have been answered by the completed studies and new questions about the outcomes of high-risk infants that must be addressed by ongoing and future studies.

Disparities and Early Engagement Associated with the 18- to 36-Month High-Risk Infant Follow-Up Visit among Very Low Birthweight Infants in California

OBJECTIVE

To determine follow-up rates for the high-risk infant follow-up (HRIF) visit at 18-36 months among infants with very low birthweights and identify factors associated with completion.

STUDY DESIGN

We completed a retrospective cohort study using linked California Perinatal Quality of Care Collaborative neonatal intensive care unit, California Perinatal Quality of Care Collaborative California Children's Services HRIF, and Vital Statistics Birth Cohort databases. We identified maternal, sociodemographic, neonatal, clinical, and HRIF program level factors associated with the 18- to 36-month follow-up using multivariable Poisson regression.

RESULTS

From 2010 to 2015, among 19 284 infants with very low birthweight expected to attend at least 1 visit at 18-36 months, 10 249 (53%) attended. On multivariable analysis, factors independently associated with attendance at an 18- to 36-month visit included estimated gestational age (relative risk [RR], 1.21; 95% CI, 1.15-1.26; <26 weeks vs ≥31 weeks), maternal education (RR, 1.09; 95% CI, 1.06-1.12; college degree or more vs high school), distance from clinic (RR, 0.92; 95% CI, 0.89-0.97; fourth quartile vs first quartile), and Black non-Hispanic race vs White race (RR, 0.88; 95% CI, 0.84-0.92). However, completion of an initial HRIF visit within the first 12 months was the factor most strongly associated with completion of an 18- to 36-month visit (RR, 6.47; 95% CI, 5.91-7.08).

CONCLUSIONS

In a California very low birthweight cohort, maternal education, race, and distance from the clinic were associated with sustained HRIF participation, but attendance at a visit by 12 months was the most significantly associated factor. These findings highlight the importance of early engagement with all families to ensure equitable follow-through for children born preterm.

Growth Trajectories during the First 6 Years in Survivors Born at Less Than 25 Weeks of Gestation Compared with Those between 25 and 29 Weeks

We aimed to determine the differences in the growth trajectories of the youngest gestational survivors (<25 weeks’ gestation) up to 6 years of age compared to those of older gestational ages. Preterm infants were divided into two groups: 22−24 weeks’ gestation (male (M) 16, female (F) 28) and 25−29 weeks’ gestation (M 84, F 59). Z-scores of body weight (BW), body length (BL), and body mass index (BMI) were derived from Japanese standards at 1, 1.5, 3, and 6 years of corrected age. Comparisons between the two groups by sex were made using the Wilcoxon test and linear regression analysis to examine the longitudinal and time-point associations of anthropometric z-scores, the presence of small for gestational age (SGA), and the two gestational groups. BW, BL, BMI, and z-scores were significantly lower in the 22−24 weeks group at almost all assessment points. However, there were no significant differences in BW, BL, BMI, and z-scores between the two female groups after 3 years. BMI z-scores were significantly associated with the youngest gestational age and the presence of SGA at all ages in males, but not in females. The youngest gestational age had a greater influence in males on the z-score of anthropometric parameters up to 6 years of age.

Fluctuations in internal cerebral vein and central side veins of preterm infants

BACKGROUND

Studies on the acute management of extremely low birthweight (ELBW) infants reveal a high incidence of intraventricular hemorrhage (IVH) in infants with high-grade internal cerebral vein perfusion waveform fluctuations. In this prospective observational study we investigated the Doppler perfusion waveform fluctuations in the great cerebral vein, straight sinus, and internal cerebral veins of ELBW infants.

METHODS

We evaluated perfusion waveforms after birth every 12 h until 120 h in 73 ELBW infants (<1,000 g) at our hospital. Fluctuations were categorized into four patterns of increasing magnitude, Grades 0-3.

RESULTS

The maximum grades of perfusion waveform fluctuations of the internal cerebral veins were 0, 1, 2, and 3 detected in 12, 38, 13, and 10 infants, respectively; those of the great cerebral vein were 0, 1, 2, and 3 detected in 5, 17, 20, and 31 infants, respectively; and those of the straight sinus were 0, 1, 2, and 3 detected in 1, 5, 17, and 50 infants, respectively. Only one of 803 simultaneous measurements of the Doppler perfusion waveforms showed stronger fluctuations of the peripheral vein than those of the central side veins. Intraventricular hemorrhage was associated with high-grade fluctuations in the internal cerebral veins but not in the great cerebral vein or straight sinus.

CONCLUSIONS

Most infants had high-grade fluctuations in the great cerebral vein and straight sinus, with lower grade fluctuations in the internal cerebral vein, but IVH was not associated with those markers. Intraventricular hemorrhage was correlated with high-grade fluctuations only in the internal cerebral veins.

Global prevalence of long-term neurodevelopmental impairment following extremely preterm birth: a systematic literature review

Objective

Neurodevelopmental impairment (NDI) is a major complication of extreme prematurity. This systematic review was conducted to summarize the worldwide long-term prevalence of NDI associated with extreme prematurity.

Methods

Embase and MEDLINE databases were searched for epidemiologic and observational/real-world studies, published in English between 2011 and 2016, reporting long-term prevalence of NDI (occurring from 1 year) among extremely preterm infants born at gestational age (GA) ≤28 weeks.

Results

Of 2406 articles identified through searches, 69 met the protocol NDI definition (24 North America, 25 Europe, 20 Rest of World). Prevalence of any severity NDI in North America was 8%–59% at 18 months to 2 years, and 11%–37% at 2–5 years; prevalence of moderate NDI in Europe was 10%–13% at 18 months to 2 years, 3% at 2–5 years, and 9%–19% at ≥5 years; prevalence of any NDI in Rest of World was 15%–61% at 18 months to 2 years, and 42% at 2–5 years (no North America/Rest of World studies reported any NDI at ≥5 years). A trend toward higher prevalence of NDI with lower GA at birth was observed.

Conclusions

Extreme prematurity has a significant long-term worldwide impact on neurodevelopmental outcomes.

Electroencephalography monitoring in the neonatal intensive care unit: a Chinese perspective

BACKGROUND

Electroencephalography (EEG) is an accessible technique for bedside monitoring of the cerebral function in the neonatal intensive care unit (NICU). The popularization of EEG in the field of newborns in China is relatively late compared with western countries. To learn more about current practices and improvement of EEG monitoring, we conducted a survey to describe current utilization of EEG in NICU in China.

METHODS

A cross-sectional electronic survey with 21-items about EEG using in NICU was administered for pediatricians in China on the official website of "Questionnaire Star".

RESULTS

A total of 251 participants were involved, in which 64% of them reported using EEG. EEG was employed in NICUs of Children's hospitals (97%), and grade III, class A hospitals (69%). Besides, neonatal encephalopathy and suspected seizures were the most common indications for use. In clinical practice, the vast majority of physicians managed their patients on the basis of EEG (93%). Pediatricians prefer to use conventional video-EEG (cEEG) to detect seizures and make the diagnosis of encephalopathy. Both amplitude integrated EEG (aEEG) (78%) and cEEG (56%) were mainly interpreted by neonatologists. However, only 56% of respondents had ever taken a formal EEG training course. Overall, 96% of the respondents reported that they would be interested in attending an education session on EEG in the NICU. aEEG interpretation was the most interesting part to learn (81%). For those who were not using EEG, cost (43%) and difficulty interpretation (30%) were reported as barriers to use.

CONCLUSIONS

The utilization rate of EEG in NICU in China is significantly lower than the international level. There is an urgent need for standardized training and financial support for neonatologists in the use of EEG and interpretation of aEEG results.

Trends in survival, neonatal morbidity and neurodevelopmental outcome of very preterm infants in Tainan, Southern Taiwan, 1995-2016

BACKGROUND

Using regression modeling analysis to investigate the breakpoints of the trends in survival-without-major-neonatal-morbidities (MNM) or -without-neurodevelopmental- impairment (NDI) by year and gestational age (GA) in preterm infants.

METHODS

We enrolled 2237 preterm infants (GA < 32 weeks) in Tainan, Taiwan. The trends in survival-without-MNM or -without-NDI by year (1995-2016) and GA (23-31 weeks), and the epochs and GA ranges with distinct changes were examined. Adjusted rate ratios (aRR) (95% confidence interval [CI]) were calculated using the rates in infants born at 23 weeks in 1995 as the reference.

RESULTS

For yearly trend, there were three epochs (1995-2000, 2001-2006, 2007-2016) with distinct changes in the rates of survival-without-MNM (aRR [95% CI] 1.07 [1.02-1.12], 1.04 [1.02-1.07], 1.02 [1.01-1.04]) and -without-NDI (1.03 [1.02-1.07], 1.02 [1.01-1.04], 1.01 [0.98-1.04]). For GA trend, the three GA ranges with different increases in the rates of survival-without-MNM were 23⁺⁰-26⁺⁶ (1.60 [1.31-1.94]), 27⁺⁰-28⁺⁶ (1.24 [1.14-1.34]) and 29⁺⁰-31⁺⁶ weeks (1.17 [1.02-1.34]), while those in the rates of survival-without-NDI were 23⁺⁰-25⁺⁶ (1.14 [1.03-1.25]), 26⁺⁰-28⁺⁶ (1.06 [1.02-1.12]) and 29⁺⁰-31⁺⁶ weeks (1.04 [1.02-1.07]). The trends in survival-without-MNM and -without-NDI increased over years in infants with GA 25-31 but not < 25 weeks.

CONCLUSION

The yearly trends in survival-without-MNM and -without-NDI had steady increases from 1995 to 2016 with distinct changes in three epochs, and the GA trends also increased with different rates per week in three GA ranges. Infants with GA < 25 weeks did not improve on the rates of survival-without-MNM or -without-NDI per year from 1995 to 2016.

Cord Blood Cytokine Levels Correlate With Types of Placental Pathology in Extremely Preterm Infants

Background: Placental abnormalities are associated with inflammation and have been linked to brain injury in preterm infants. We studied the relationship between placental pathology and the temporal profiles of cytokine levels in extremely pre-term infants. Study Design: We prospectively enrolled 55 extremely preterm infants born between June 2017 and July 2018. Levels of 27 cytokines were measured in blood drawn from the umbilical artery at birth and from infants at 1-3 and 21-28 days of life. Placental pathology was grouped as normal (N), inflammation (I), vasculopathy (V), or combined vasculopathy and inflammation (V+I). Results: Complete data was available from 42 patients. Cord blood median levels of cytokines differed between groups with the highest levels observed in group V+I as compared to groups N, I and V for the following: Eotaxin (p = 0.038), G-CSF (p = 0.023), IFN-γ (p = 0.002), IL-1ra (p < 0.001), IL-4 (p = 0.005), IL-8 (p = 0.010), MCP-1 (p = 0.011), and TNFα (p = 0.002). Post-hoc analysis revealed sex differences between and within the placental pathology groups. Conclusion: Specific types of placental pathology may be associated with differential cytokine profiles in extremely pre-term infants. Sampling from cord blood may help assess the pathological status of the placenta and potentially infer outcome risks for the infant.

Short-term outcome of very low-birth-weight infants in a tertiary care hospital in Saudi Arabia over a decade

BACKGROUND

Knowledge on short-term outcomes of preterm infants is important for quality control. Our objective was to analyze the outcomes of very low birth weight infants admitted to our neonatal intensive care unit over a ten years' period and to compare the results with internationally published data.

METHODS

We analyzed the outcome measures for all live born infants with birth weight (BW) of 400-1500 grams and gestational age (GA) of 23-32 weeks born at King Faisal Specialist Hospital & Research Centre between 2006 and 2015. Results were compared to data from four international neonatal networks.

RESULTS

During the study period, we admitted 528 infants born at a gestational age of≥23 and≤32 weeks with a very low birth weight (VLBW) of 400-1500 grams. Mean (SD) GA was 28 (2.4) weeks and mean (SD) BW was 1007 (290) grams. A hundred and twenty-nine (24.4%) infants were small for gestational age and major congenital anomalies were present in 56 (10.6 %) infants. The rate of bronchopulmonary dysplasia (BPD) was 24.4 %, necrotizing enterocolitis (NEC) 9.1%, patent ductus arteriosus (PDA) 29.9%, severe intraventricular hemorrhage (IVH)10.8 %, periventricular leukomalacia (PVL) 5.7%, severe retinopathy of prematurity (ROP) 8%, and late-onset sepsis was 18.8%. The incidences of major neonatal outcomes such as CLD, NEC, severe IVH and severe ROP were comparable to the international cohorts.

CONCLUSION

In our population of preterm infants, survival rates and complications of prematurity were comparable to international data.

Human neocortical development as a basis to understand mechanisms underlying neurodevelopmental disabilities in extremely preterm infants

AIM

Recent advances in perinatal and neonatal medicine have resulted in marked improvements in the survival rates of extremely preterm infants (born before 28 gestational weeks) around the world, and Japan is among the countries with the highest reported survival rates of extremely preterm infants. However, it remains a major concern that many survivors develop neurodevelopmental disabilities, including cognitive dysfunctions and neurodevelopmental disorders later in life. In order to understand the pathophysiological mechanisms underlying the neurodevelopmental disabilities observed in the survivors of extremely preterm births, we reviewed recently reported findings about the development of the human neocortex.

METHODS

First, we have summarized the current knowledge about the development of the neocortex, including recently reported human- and/or primate-specific developmental events. Next, we discussed the possible causal mechanisms underlying the development of neurodevelopmental disabilities in extremely preterm infants.

RESULTS

Around the birth of extremely preterm infants, neurogenesis and succeeding neuronal migrations are ongoing in the neocortex of human brain. Expansion and maturation of the subplate, which is thought to reflect the axonal wiring in the neocortex, is also prominent at this time.

CONCLUSION

Brain injuries that occur around the birth of extremely preterm infants are presumed to affect the dynamic developmental events in the neocortex, such as neurogenesis, neuronal migrations and maturation of the subplate, which could underlie the neurodevelopmental disabilities that often develop subsequently in extremely preterm infants. These possibilities should be borne in mind while considering maternal and neonatal care to further improve the long-term outcomes of extremely preterm infants.

Treatment for hypotension in the first 24 postnatal hours and the risk of hearing loss among extremely low birth weight infants

OBJECTIVE

To evaluate whether treated hypotension in the first 24 postnatal hours is associated with hearing loss in extremely low birth weight (ELBW) infants.

STUDY DESIGN

In a cohort of 735 ELBW infants, we identified 25 with sensorineural hearing loss (SNHL) at 12-24 months adjusted age. For each case, we selected three controls with normal hearing. Logistic regression models were used to adjust for confounding variables.

RESULTS

Sixty percent of cases and 25% of controls were treated for hypotension. After adjusting for confounding variables (gestational age, antenatal glucocorticoids, 5 min Apgar < 6, insertion of an umbilical catheter, treatment with high frequency ventilation, and major cranial ultrasound abnormality), treated hypotension was associated with an increased risk of SNHL (adjusted odds ratio: 3.6; 95% confidence interval: 1.3-9.7).

CONCLUSIONS

Treated hypotension in ELBW infants in the first 24 h of life is associated with an increased risk of SNHL.

Disparities in the use of antenatal corticosteroids among women with hypertension in North Carolina

OBJECTIVE

To evaluate antenatal corticosteroids (ANS) use in pregnant women with hypertension.

STUDY DESIGN

Retrospective analysis of ANS use in the Perinatal Quality Collaborative of North Carolina between 2015 and 2017.

RESULTS

Twenty-five centers participated, with 9% (1580/17,692) of mothers delivering at <34 weeks; of these, 81% (1286/1580) received a full course of ANS, which was not different between phases (p = 0.32), or between Level III/IV neonatal intensive care units (NICUs; 82%), and I/II NICUs (76%) (p = 0.05). In Level III/IV NICUs, White mothers were more likely to receive ANS (87%) than African Americans (77%) or other race/ethnicity (80%) (including Hispanics) (p = 0.001). ANS use did not differ among mothers with different payers (p = 0.94).

CONCLUSION

The rates of full ANS courses did not significantly increase from 2015-2017 and disparities persisted. Targeted efforts to improve ANS exposures among hypertensive African American and Hispanic mothers, as well as in community hospital settings are needed.

Dopaminergic Co-Regulation of Locomotor Development and Motor Neuron Synaptogenesis is Uncoupled by Hypoxia in Zebrafish

Hypoxic injury to the developing human brain is a complication of premature birth and is associated with long-term impairments of motor function. Disruptions of axon and synaptic connectivity have been linked to developmental hypoxia, but the fundamental mechanisms impacting motor function from altered connectivity are poorly understood. We investigated the effects of hypoxia on locomotor development in zebrafish. We found that developmental hypoxia resulted in decreased spontaneous swimming behavior in larva, and that this motor impairment persisted into adulthood. In evaluation of the diencephalic dopaminergic neurons, which regulate early development of locomotion and constitute an evolutionarily conserved component of the vertebrate dopaminergic system, hypoxia caused a decrease in the number of synapses from the descending dopaminergic diencephalospinal tract (DDT) to spinal cord motor neurons. Moreover, dopamine signaling from the DDT was coupled jointly to motor neuron synaptogenesis and to locomotor development. Together, these results demonstrate the developmental processes regulating early locomotor development and a requirement for dopaminergic projections and motor neuron synaptogenesis. Our findings suggest new insights for understanding the mechanisms leading to motor disability from hypoxic injury of prematurity.

Creation of a Decision Support Tool for Expectant Parents Facing Threatened Periviable Delivery: Application of a User-Centered Design Approach

BACKGROUND

Shared decision-making (SDM) is optimal in the context of periviable delivery, where the decision to pursue life-support measures or palliation is both preference sensitive and value laden. We sought to develop a decision support tool (DST) prototype to facilitate SDM by utilizing a user-centered design research approach.

METHODS

We convened four patient and provider advisory boards with women and their partners who had experienced a surviving or non-surviving periviable delivery, pregnant women who had not experienced a prior preterm birth, and obstetric providers. Each 2-h session involved design research activities to generate ideas and facilitate sharing of values, goals, and attitudes. Participant feedback shaped the design of three prototypes (a tablet application, family story videos, and a virtual reality experience) to be tested in a final session.

RESULTS

Ninety-five individuals (48 mothers/partners; 47 providers) from two hospitals participated. Most participants agreed that the prototypes should include factual, unbiased outcomes and probabilities. Mothers and support partners also desired comprehensive explanations of delivery and care options, while providers wanted a tool to ease communication, help elicit values, and share patient experiences. Participants ultimately favored the tablet application and suggested that it include family testimonial videos.

CONCLUSION

Our results suggest that a DST that combines unbiased information and understandable outcomes with family testimonials would be meaningful for periviable SDM. User-centered design was found to be a useful method for creating a DST prototype that may lead to improved effectiveness, usability, uptake, and dissemination in the future, by leveraging the expertise of a wide range of stakeholders.

Human Placental Vascular Reactivity in Health and Disease: Implications for the Treatment of Pre-eclampsia

Adequate development of the placenta is essential for optimal pregnancy outcome. Pre-eclampsia (PE) is increasingly recognized to be a consequence of placental dysfunction and can cause serious maternal and fetal complications during pregnancy. Furthermore, PE increases the risk of neonatal problems and has been shown to be a risk factor for cardiovascular disease of the mother later in life. Currently, there is no adequate treatment for PE, mainly because its multifactorial pathophysiology remains incompletely understood. It originates in early pregnancy with abnormal placentation and involves a cascade of dysregulated systems in the placental vasculature. To investigate therapeutic strategies it is essential to understand the regulation of vascular reactivity and remodeling of blood vessels in the placenta. Techniques using human tissue such as the ex vivo placental perfusion model provide insight in the vasoactive profile of the placenta, and are essential to study the effects of drugs on the fetal vasculature. This approach highlights the different pathways that are involved in the vascular regulation of the human placenta, changes that occur during PE and the importance of focusing on restoring these dysfunctional systems when studying treatment strategies for PE.

Changes in Mortality and Cerebral Palsy in Extremely Low-Birth-Weight Infants in a Tertiary Center in Hong Kong

Introduction. We retrospectively reviewed a cohort of extremely low-birth-weight (ELBW) babies born at Queen Mary Hospital and explored if there is any time trend in survival and short-term neurodevelopmental outcomes. Methods. We included ELBW infants born at Queen Mary Hospital between 2008 and 2015. The relationships between multiple risk factors with survival and neurodevelopmental outcomes were analyzed by either Cox regression or univariate logistic regression analysis. We also compared this birth-year period with our previous study from 1993 to 2002. Results. Two hundred seventeen ELBW infants were delivered during the study period. There was significantly higher overall survival rate (81.1%) in 2008 to 2015 compared with 71.4% in 1993 to 2002. One hundred forty-three out of 176 (81%) survivors were assessed at a corrected mean age of 18.1 months. A total of 4.2% had cerebral palsy. There were significantly lower rates of cerebral palsy in 2008 to 2015 (4.2%) compared with 1993 to 2002 (13.5%). Conclusions. We showed a temporal improvement in survival and short-term neurodevelopmental outcomes.

Improved Referral of Very Low Birthweight Infants to High-Risk Infant Follow-Up in California

OBJECTIVE

To examine changes in referral rates of very low birthweight (birthweight <1500 g) infants to high-risk infant follow-up in California and identify factors associated with referral before and after implementation of a statewide initiative in 2013 to address disparities in referral.

STUDY DESIGN

We included very low birthweight infants born 2010-2016 in the population-based California Perinatal Quality Care Collaborative who survived to discharge home. We used multivariable logistic regression to examine factors associated with referral and derive risk-adjusted referral rates by neonatal intensive care unit (NICU) and region.

RESULTS

Referral rate improved from 83.0% (preinitiative period) to 94.9% (postinitiative period); yielding an OR of 1.48 (95% CI, 1.26-1.72) for referral in the postinitiative period after adjustment for year. Referral rates improved the most (≥15%) for infants born at ≥33 weeks of gestation, with a birthweight of 1251-1500 g, and born in intermediate and lower volume NICUs. After the initiative, Hispanic ethnicity, small for gestational age status, congenital anomalies, and major morbidities were no longer associated with a decreased odds of referral. Lower birthweight, outborn status, and higher NICU volume were no longer associated with increased odds of referral. African American race was associated with lower odds of referral, and higher NICU level with a higher odds of referral during both time periods. Referral improved in many previously poor-performing NICUs and regions.

CONCLUSIONS

High-risk infant follow-up referral of very low birthweight infants improved substantially across all sociodemographic, perinatal, and clinical variables after the statewide initiative, although disparities remain. Our results demonstrate the benefit of a targeted initiative in California, which may be applicable to other quality collaboratives.

Ontogeny of inter-alpha inhibitor protein (IAIP) expression in human brain

Inter-alpha inhibitor proteins (IAIPs) are naturally occurring immunomodulatory molecules found in most tissues. We have reported ontogenic changes in the expression of IAIPs in brain during development in sheep and abundant expression of IAIPs in fetal and neonatal rodent brain in a variety of cellular types and brain regions. Although a few studies identified bikunin, light chain of IAIPs, in adult human brain, the presence of the complete endogenous IAIP protein complex has not been reported in human brain. In this study, we examined the immunohistochemical expression of endogenous IAIPs in human cerebral cortex from early in development through the neonatal period and in adults using well-preserved postmortem brains. We examined total, nuclear, and cytoplasmic staining of endogenous IAIPs and their expression in neurofilament light polypeptide-positive neurons and glial fibrillary acidic protein (GFAP)-positive astrocytes. IAIPs were ubiquitously detected for the first time in cerebral cortical cells at 24-26, 27-28, 29-36, and 37-40 weeks of gestation and in adults. Quantitative analyses revealed that IAIPs were predominately localized in the nucleus in all age groups, but cytoplasmic IAIP expression was more abundant in adult than in the younger ages. Immunoreactivity of IAIPs was expressed in neurons and astrocytes in all age groups. In addition, IAIP co-localization with GFAP-positive astrocytes was more abundant in adults than in the developing brain. We conclude that IAIPs exhibit ubiquitous expression, and co-localize with neurons and astrocytes in the developing and adult human brain suggesting a potential role for IAIPs in development and endogenous neuroprotection.

Neuroprotection Strategies in Preterm Encephalopathy

Advances in neonatology have led to unprecedented improvements in neonatal survival such that those born as early as 22 weeks of gestation now have some chance of survival, and over 70% of those born at 24 weeks of gestation survive. Up to 50% of infants born extremely preterm develop poor outcomes involving long-term neurodevelopmental impairments affecting cognition and learning, or motor problems such as cerebral palsy. Poor outcomes arise because the preterm brain is vulnerable both to direct injury (by events such as intracerebral hemorrhage, infection, and/or hypoxia), or indirect injury due to disruption of normal development. This neonatal brain injury and/or dysmaturation is called "encephalopathy of prematurity". Current and future strategies to improve outcomes in this population include prevention of preterm birth, and pre-, peri-, and postnatal approaches to protect the developing brain. This review will describe mechanisms of preterm brain injury, and current and upcoming therapies in the antepartum and postnatal period to improve preterm encephalopathy.

Developmental Outcomes of Extremely Preterm Infants with a Need for Child Protective Services Supervision

OBJECTIVE

To evaluate neurodevelopmental outcomes of preterm infants with need for Child Protective Services (CPS) supervision at hospital discharge compared with those discharged without CPS supervision.

STUDY DESIGN

For infants born at <27 weeks of gestation between 2006 and 2013, prospectively collected maternal and neonatal characteristics and 18- to 26-month corrected age follow-up data were analyzed. Bayley-III cognitive and language scores of infants with discharge CPS supervision were compared with infants without CPS supervision using regression analysis while adjusting for potentially confounding variables, including entering CPS after discharge from the hospital.

RESULTS

Of the 4517 preterm infants discharged between 2006 and 2013, 255 (5.6%) were discharged with a need for CPS supervision. Mothers of infants with CPS supervision were significantly more likely to be younger, single, and gravida ≥3; to have less than a high school education; and to have a singleton pregnancy and less likely to have received prenatal care or antenatal steroids. Despite similar birth weight and medical morbidities, the CPS group had longer hospital stays compared with the non-CPS group. In adjusted analysis, cognitive scores were points lower (B = -1.94; 95% CI, -3.88 to -0.08; P = .04) in the CPS at discharge group compared with the non-CPS group. In children who entered CPS supervision after hospital discharge (an additional 106 infants), cognitive scores were 4 points lower (β = -4.76; 95% CI, -7.47 to -2.05; P < .001) and language scores were 5 points lower (β = -4.93; 95% CI, -8.00 to -1.86; P = .002).

CONCLUSION

Extremely preterm infants discharged from the hospital with CPS supervision or entering CPS postdischarge are at increased risk for cognitive delay at 2 years of age. Opportunities exist to intervene and potentially improve outcomes in this vulnerable group of children.

Perceptions of Australian and New Zealand clinicians caring for neonates born at the borderline of viability have changed since the 2005 consensus guideline

AIM

To determine whether clinician and consumer considerations have changed regarding the resuscitation and support of neonates born at the borderlines of viability since the 2005 New South Wales (NSW) and Australian Capital Territory (ACT) consensus guidelines were developed.

METHODS

A prospective survey based on the hypotheses and scenarios developed in the original NSW and ACT consensus workshop on perinatal care at the borderlines of viability was sent to neonatologists, fetal medicine specialists, clinical midwife and clinical neonatal consultants and consumer representatives in Australia and New Zealand. Four scenarios and 16 questions were used to explore the respondent's views towards different aspects of the management of neonates born at the borderlines of viability. Australian and New Zealand Neonatal Network data from 2013 or NSW/ACT Neonatal Intensive Care Units (NICUS) data from 1998 to 2004 were used to provide outcome data for each scenario.

RESULTS

A total of 87% or more of respondents advocated for resuscitation of neonates at 24 and 25 weeks' gestation in 2015. Only 29% (49/169) would agree to parental request not to resuscitate at 25 weeks and only 10% (17/170) at 26^0-6 weeks. The number of perinatal clinical care providers considering resuscitation at 23⁵ weeks' gestation increased from 23% in 2005 to more than 50% in 2015.

CONCLUSION

These findings support the development of updated guidelines for the management of neonates in Australia and New Zealand born at the borderlines of viability to reflect the changes in clinical perceptions and management.

The impact of decision quality on mental health following periviable delivery

PURPOSE

To assess the relationship between decision quality and mental health outcomes for women and their important others (IO) 3 months following periviable birth.

METHOD

Mental health outcomes were assessed prior to delivery and at 3 months postpartum using depression (PHQ-9), anxiety (GAD-7), and post-traumatic stress disorder (PTSD) (IES-22) scales. Decision quality was measured in terms of Decisional Conflict, Control, Regret, and Satisfaction with Decision. Descriptive analyses and linear regression modeling were conducted using SAS version 9.4.

RESULT

We recruited 30 eligible women and 16 IOs. Participants had mild anxiety and depression, and symptoms of PTSD were among bereaved parents. Participants with lower decision control had higher levels of depression (women: p = 0.014; IOs: p = 0.059) and anxiety (women: p = 0.053; IOs: p = 0.032). Depression was also associated with higher decisional regret (women: p = 0.073; IOs: p = 0.023).

CONCLUSION

Our findings suggest that decision quality is associated with mental health outcomes for families who experience periviable delivery.

Lack of social support as measured by the Family Resource Scale screening tool is associated with early adverse cognitive outcome in extremely low birth weight children

OBJECTIVE

Extremely low birth weight children are at high risk for cognitive impairment.

STUDY DESIGN

Cognitive outcome of extremely low birth weight children participating in a Neonatal Research Network, randomized trial was evaluated at 18 and 30 months corrected age using the Bayley Scales of Infant Development, 2nd ed. Family resources and social support were assessed using a Family Resource Scale parent questionnaire. Regression analysis was used to determine independent demographic, medical, and family resource factors influencing longitudinal cognitive outcome.

RESULT

Higher Family Resource Scale scores at 18 months were associated with greater improvement in cognitive scores between 18 and 30 months. Cognitive outcome was most adversely affected in children whose families had the least resources and social support. The adverse effect of poor social support was independent of family income.

CONCLUSION

Poor interpersonal social support has an independent, adverse impact on cognitive outcomes of extremely low birth weight infants.

Early Life Supraphysiological Levels of Oxygen Exposure Permanently Impairs Hippocampal Mitochondrial Function

Preterm infants requiring prolonged oxygen therapy often develop cognitive dysfunction in later life. Previously, we reported that 14-week-old young adult mice exposed to hyperoxia as newborns had spatial and learning deficits and hippocampal shrinkage. We hypothesized that the underlying mechanism was the induction of hippocampal mitochondrial dysfunction by neonatal hyperoxia. C57BL/6J mouse pups were exposed to 85% oxygen or room air from P2-P14. Hippocampal proteomic analysis was performed in young adult mice (14 weeks). Mitochondrial bioenergetics were measured in neonatal (P14) and young adult mice. We found that hyperoxia exposure reduced mitochondrial ATP-linked oxygen consumption and increased state 4 respiration linked proton leak in both neonatal and young adult mice while complex I function was decreased at P14 but increased in young adult mice. Proteomic analysis revealed that hyperoxia exposure decreased complex I NDUFB8 and NDUFB11 and complex IV 7B subunits, but increased complex III subunit 9 in young adult mice. In conclusion, neonatal hyperoxia permanently impairs hippocampal mitochondrial function and alters complex I function. These hippocampal mitochondrial changes may account for cognitive deficits seen in children and adolescents born preterm and may potentially be a contributing mechanism in other oxidative stress associated brain disorders.

Magnesium protects mouse hippocampal HT22 cells against hypoxia-induced injury by upregulation of miR-221

Magnesium (Mg²⁺ ) has been shown to exert neuroprotective effects against hypoxia. However, it still remains elusive whether Mg²⁺ protected mouse hippocampal HT22 cells against hypoxia-evoked damages. Therefore, we aimed to investigate the function of Mg²⁺ and mechanisms associated with microRNA-221 (miR-221). HT22 cells were exposed to 3% O₂ for 24 hours to induce hypoxic damages with 21% as a normoxic culture condition. The damages were monitored by viability, migration, and apoptosis of HT22 cells with or without Mg²⁺ pretreatment. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was applied to examine the alteration of miR-221, miR-210, and miR-17-5p. Transduction was carried out to artificially alter the expression of miR-221 and nerve growth factor (NGF), which was confirmed by qRT-PCR or Western blot assays. To blunt phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and nuclear factor κB (NF-κB), LY294002 (10 µM) and BAY 11-7082 (10 µM) were used. We observed Mg²⁺ protected HT22 cells against hypoxia-induced damages by upregulating miR-221. Further, miR-221 positively regulated NGF expression. Overexpression of NGF alleviated cell injury, while suppression of NGF aggravated cell injury. Moreover, miR-221 elevated NGF by inducing phosphorylation of regulators in PI3K/AKT and NF-κB transduction cascades and then alleviated cell injury. In conclusion, Mg²⁺ protected HT22 cells against hypoxia-induced damages by upregulation of miR-221 and NGF. These findings provided insights into the development of improved strategies for clinical application.

Neurodevelopmental outcomes of extremely preterm infants in New South Wales and the Australian Capital Territory

AIM

This study aimed to provide updated information on gestation-specific neurodevelopmental outcomes of extremely to very preterm infants 23-28 weeks' gestation admitted to neonatal intensive care units (NICUs).

METHODS

This was a population-based retrospective cohort study of infants born between 23⁺⁰ and 28⁺⁶ weeks' gestation and admitted to a network of NICUs between 2007 and 2012 in a well-defined geographic area of New South Wales (NSW) and the Australian Capital Territory (ACT). Primary outcome was moderate to severe neurodevelopmental impairment.

RESULTS

Of 2287 infants admitted to NICUs, 1914 (83.7%) survived to discharge, and 1514 (79.8% = 1514/1897) were followed up. Moderate to severe neurodevelopmental impairment was 11% overall, and the incidence decreased with increasing gestational age (GA): 25, 23, 15, 13, 9 and 7% at 23, 24, 25, 26, 27 and 28 weeks, respectively. Male gender, major intraventricular haemorrhage, late-onset sepsis, chronic lung disease and post-natal corticosteroid therapy were found to be independently associated with increased risk of moderate to severe impairment. Compared with an incidence of 16% in the 1998-2004 cohort, there was a significant reduction in moderate to severe neurodevelopmental impairment in the current cohort (unadjusted odds ratio: 0.65, 95% confidence interval: 0.52-0.80).

CONCLUSIONS

We report the latest neurodevelopmental outcomes of extremely to very preterm infants in NSW and the ACT. Neurodevelopmental outcome rates based on GA alone may not provide the true estimate as these outcomes can vary based on the presence or absence of other relevant perinatal factors.

Randomized Trial of 42-Day Compared with 9-Day Courses of Dexamethasone for the Treatment of Evolving Bronchopulmonary Dysplasia in Extremely Preterm Infants

OBJECTIVE

To compare pulmonary and neurodevelopmental outcomes in extremely preterm infants with evolving bronchopulmonary dysplasia treated with either a 42-day course of dexamethasone or 9-day course(s) of dexamethasone.

STUDY DESIGN

This was a prospective, randomized study in 59 infants ≤27 weeks of gestation born between October 2006 and December 2010, who at day 10-21 of life had ventilatory support with mean airway pressure ≥8 cm H₂O and FiO₂ ≥60%. Infants received dexamethasone 0.5 mg/k/day × 3 days followed by a slow taper (42-day group, n = 30) or dexamethasone 0.5 mg/k/day followed by a rapid taper (9-day group, n = 29). Infants in the 9-day group received additional 9-day courses if they again required entry support. The primary outcome was intact survival (normal neurologic examination, IQ >70, and functioning in school without supplemental educational support) at 7 years of age.

RESULTS

The 42-day and 9-day groups were similar for mean gestational age (25 weeks) and all baseline characteristics. Nineteen of 29 infants (66%) in the 9-day group received only 1 course of dexamethasone; therefore, the total steroid dose for the 42-day group (7.56 mg/kg) was significantly greater than that for the 9-day group (4.04 mg/kg), P < .001. Infants in the 42-day group had shorter duration of ventilation (25 vs 37 days), P < .005, received fewer transfusions (2 vs 3.5), P < .01, and reached full enteral feeds earlier (40 vs 46 days), P < .05. Intact survival at school age was significantly increased in the 42-day group (75%) compared with the 9-day group (34%), P < .005.

CONCLUSION

A 42-day tapering course of dexamethasone in extremely preterm infants at high risk for bronchopulmonary dysplasia decreased hospital morbidities and increased rate of survival without handicap compared with a treatment protocol that attempted to minimize steroid exposure.

Placental effects and transfer of sildenafil in healthy and preeclamptic conditions

Background

The phosphodiesterase-5 inhibitor (PDE5) sildenafil has emerged as a promising treatment for preeclampsia (PE). However, a sildenafil trial was recently halted due to lack of effect and increased neonatal morbidity.

Methods

Ex vivo dual-sided perfusion of an isolated cotyledon and wire-myography on chorionic plate arteries were performed to study the effects of sildenafil and the non-selective PDE inhibitor vinpocetine on the response to the NO donor sodium nitroprusside (SNP) under healthy and PE conditions. Ex vivo perfusion was also used to study placental transfer of sildenafil in 6 healthy and 2 PE placentas. Furthermore, placental mRNA and protein levels of eNOS, iNOS, PDE5 and PDE1 were quantified.

Findings

Sildenafil and vinpocetine significantly enhanced SNP responses in chorionic plate arteries of healthy, but not PE placentas. Only sildenafil acutely decreased baseline tension in arteries of both healthy and PE placentas. At steady state, the foetal-to-maternal transfer ratio of sildenafil was 0·37 ± 0·03 in healthy placentas versus 0·66 and 0·47 in the 2 PE placentas. mRNA and protein levels of PDE5, eNOS and iNOS were comparable in both groups, while PDE1 levels were lower in PE.

Interpretation

The absence of sildenafil-induced NO potentiation in arteries of PE placentas, combined with the non-PDE-mediated effects of sildenafil and the lack of PDE5 upregulation in PE, argue against sildenafil as the preferred drug of use in PE. Moreover, increased placental transfer of sildenafil in PE might underlie the neonatal morbidity in the STRIDER trial.

Fund

This study was funded by an mRACE Erasmus MC grant.

Online Information About Periviable Birth: Quality Assessment

BACKGROUND

Over 20,000 parents in the United States face the challenge of participating in decisions about whether to use life support for their infants born on the cusp of viability every year. Clinicians must help families grasp complex medical information about their baby's immediate prognosis as well as the risk for significant long-term morbidity. Patients faced with this decision want supplemental information and frequently seek medical information on the Internet. Empirical evidence about the quality of websites is lacking.

OBJECTIVE

We sought to evaluate the quality of online information available about periviable birth and treatment options for infants born at the cusp of viability.

METHODS

We read a counseling script to 20 pregnant participants that included information typically provided by perinatal and neonatal providers when periviable birth is imminent. The women were then asked to list terms they would use to search the Internet if they wanted additional information. Using these search terms, two reviewers evaluated the content of websites obtained via a Google search. We used two metrics to assess the quality of websites. The first was the DISCERN instrument, a validated questionnaire designed to assess the quality of patient-targeted health information for treatment choices. The second metric was the Essential Content Tool (ECT), a tool designed to address key components of counseling around periviable birth as outlined by professional organizations. DISCERN scores were classified as low quality if scores were 2, fair quality if scores were 3, and high quality if scores were 4 or higher. Scores of 6 or higher on the ECT were considered high quality. Interreviewer agreement was assessed by calculated kappa statistic.

RESULTS

A total of 97 websites were reviewed. Over half (57/97, 59%) were for-profit sites, news stories, or personal blogs; 28% (27/97) were government or medical sites; and 13% (13/97) were nonprofit or advocacy sites. The majority of sites scored poorly in DISCERN questions designed to assess the reliability of information presented as well as data regarding treatment choices. Only 7% (7/97) of the websites were high quality as defined by the DISCERN tool. The majority of sites did not address the essential content defined by the ECT. Importantly, only 18% of websites (17/97) indicated that there are often a number of reasonable approaches to newborn care when faced with periviable birth. Agreement was strong, with kappa ranging from .72 to .91.

CONCLUSIONS

Most information about periviable birth found on the Internet using common search strategies is of low quality. News stories highlighting positive outcomes are disproportionately represented. Few websites discuss comfort care or how treatment decisions impact quality of life.

Perinatal outcomes including long-term neuropsychiatric hospitalizations of offspring conceived during intrauterine contraceptive device use

OBJECTIVE

To investigate short-term adverse perinatal outcomes and long-term neuropsychiatric hospitalizations through 18 years of age in offspring conceived during copper intrauterine device (IUD) use.

STUDY DESIGN

We conducted a population-based cohort study comparing the pregnancy outcomes after 22 weeks of women who conceived with a copper IUD that was removed, women with a retained IUD and pregnancies without an IUD. Deliveries occurred between the years 1991 and 2014. We used a multivariable generalized estimating equation (GEE) logistic regression model analysis to control for confounders and for maternal clusters, a Kaplan-Meier survival curve to compare cumulative neuropsychiatric hospitalizations incidence and a Cox proportional-hazards model to evaluate long-term neuropsychiatric hospitalizations.

RESULTS

During the study period there were 221,805 deliveries, of which 203 (0.09%) and 149 (0.06%) occurred in patients with removed or retained copper IUD, respectively. Using GEE models, preterm delivery was independently associated with copper IUD use [odds ratio (OR) 2.1, 95% confidence interval (CI) 1.4-3.2 and OR 2.3, 95% CI 1.4-3.7 for removed and retained IUD, respectively]. We did not find an association between copper IUD presence or removal and the offspring's long-term neuropsychiatric hospitalizations (total long-term neuropsychiatric hospitalizations: 2.5%, 4.4% and 3.2% for removed, retained and no IUD, respectively, p=.71). Long-term neuropsychiatric hospitalization rate was comparable between the groups (Kaplan-Meier survival curve log rank p=.23).

CONCLUSION

Pregnancies in women who conceive with a removed or retained copper IUD are at an increased risk for short-term adverse perinatal outcomes, especially preterm delivery. For pregnancies that continued to at least 22 weeks, we found no benefit in IUD removal. However, the risk of long-term neuropsychiatric hospitalizations is not increased among offspring of these women.

IMPLICATIONS

Our data are insufficient to make a recommendation as to whether removal or retention of a copper IUD during pregnancy is best, as after 22 weeks' gestation we have found no benefit in IUD removal. Careful surveillance and categorization of the pregnancy as "high risk" are warranted.

How Early Can a Seizure Happen? Pathophysiological Considerations of Extremely Premature Infant Brain Development

Seizures in neonates represent a neurologic emergency requiring prompt recognition, determination of etiology, and treatment. Yet, the definition and identification of neonatal seizures remain challenging and controversial, in part due to the unique physiology of brain development at this life stage. These issues are compounded when considering seizures in premature infants, in whom the complexities of brain development may engender different clinical and electrographic seizure features at different points in neuronal maturation. In extremely premature infants (< 28 weeks gestational age), seizure pathophysiology has not been explored in detail. This review discusses the physiological and structural development of the brain in this developmental window, focusing on factors that may lead to seizures and their consequences at this early time point. We hypothesize that the clinical and electrographic phenomenology of seizures in extremely preterm infants reflects the specific pathophysiology of brain development in that age window.

Neuroprotective Care of Extremely Preterm Infants in the First 72 Hours After Birth

Birth at extremely low gestational ages presents a significant threat to infants' survival, health, development, and future well-being. After birth, a critical period of brain development must continue outside the womb. Neuro-supportive and neuroprotective family centered developmental care for and standardized care practices for extremely preterm infants have been shown to improve outcomes. Neuroprotective interventions must include a focus on the emotional connections of infants and their families. Being in skin-to-skin contact with the mother is the developmentally expected environment for all mammals and is especially important for supporting physiologic stability and neurodevelopment of preterm infants.

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.

Sex-specific alterations in preterm brain

BACKGROUND

The literature on brain imaging in premature infants is mostly made up of studies that evaluate neonates, yet the most dynamic time of brain development happens from birth to 1 year of age. This study was designed to obtain quantitative brain measures from magnetic resonance imaging scans of infants born prematurely at 12 months of age.

METHODS

The subject group was designed to capture a wide range of gestational age (GA) from premature to full-term infants. An age-specific atlas generated quantitative brain measures. A regression model was used to predict effects of GA and sex on brain measures.

RESULTS

There was a primary effect of sex on: (1) intracranial volume, males > females; (2) proportional cerebral cortical gray matter (females > males), and (3) cerebral white matter (males > females). GA predicted cerebral volume and cerebral spinal fluid. GA also predicted cortical gray matter in a sex-specific manner with GA having a significant effect on cortical volume in the males, but not in females.

CONCLUSIONS AND RELEVANCE

Sex differences in brain structure are large early in life. GA had sex-specific effects highlighting the importance evaluating sex effects in neurodevelopmental outcomes of premature infants.

Hypoxia and connectivity in the developing vertebrate nervous system

The developing nervous system depends upon precise regulation of oxygen levels. Hypoxia, the condition of low oxygen concentration, can interrupt developmental sequences and cause a range of molecular, cellular and neuronal changes and injuries. The roles and effects of hypoxia on the central nervous system (CNS) are poorly characterized, even though hypoxia is simultaneously a normal component of development, a potentially abnormal environmental stressor in some settings, and a clinically important complication, for example of prematurity. Work over the past decade has revealed that hypoxia causes specific disruptions in the development of CNS connectivity, altering axon pathfinding and synapse development. The goals of this article are to review hypoxia's effects on the development of CNS connectivity, including its genetic and molecular mediators, and the changes it causes in CNS circuitry and function due to regulated as well as unintended mechanisms. The transcription factor HIF1α is the central mediator of the CNS response to hypoxia (as it is elsewhere in the body), but hypoxia also causes a dysregulation of gene expression. Animals appear to have evolved genetic and molecular responses to hypoxia that result in functional behavioral alterations to adapt to the changes in oxygen concentration during CNS development. Understanding the molecular pathways underlying both the normal and abnormal effects of hypoxia on CNS connectivity may reveal novel insights into common neurodevelopmental disorders. In addition, this Review explores the current gaps in knowledge, and suggests important areas for future studies.

Summary: The nervous system's exposure to hypoxia has developmental and clinical relevance. In this Review, the authors discuss the effects of hypoxia on the development of the CNS, and its long-term behavioral and neurodevelopmental consequences.

Neurodevelopmental Outcomes in Infants With Birth Weight ≤500 g at 3 Years of Age

OBJECTIVES

To determine neurodevelopmental outcomes at 3 years of age in children born with a birth weight (BW) of ≤500 g.

METHODS

Infants who were born with a BW of ≤500 g from 2003 to 2012 in the Neonatal Research Network of Japan and survived to discharge from the NICU were eligible in this study. The study population consisted of 460 children (56.7% of 811 surviving infants) who were evaluated at 36 to 42 months of age. Neurodevelopmental impairment (NDI) was defined as having cerebral palsy, visual impairment, hearing impairment, or a developmental quotient score of <70.

RESULTS

The overall proportion of NDI was 59.1% (95% confidence interval [CI]: 54.6%-63.5%). The trend revealed no significant change during the study period. In a multivariate modified Poisson regression analysis, NDI was associated with severe intraventricular hemorrhage (adjusted risk ratio [RR]: 1.42; 95% CI: 1.19-1.68; P < .01), cystic periventricular leukomalacia (adjusted RR: 1.40; 95% CI: 1.13-1.73; P < .01), severe necrotizing enterocolitis (adjusted RR: 1.31; 95% CI: 1.07-1.60; P < .01), surgical ligation for patent ductus arteriosus (adjusted RR: 1.29; 95% CI: 1.09-1.54; P < .01), and male sex (adjusted RR: 1.19; 95% CI: 1.01-2.40; P = .04).

CONCLUSIONS

This cohort showed that neurodevelopmental outcomes of infants with a BW of ≤500 g have not improved from 2003 to 2012. Multivariate analysis revealed that severe intracranial hemorrhage and cystic periventricular leukomalacia were the strongest risk factors for NDIs. Our data suggested that measures aimed at reducing neurologic morbidities will be important for improving outcomes of infants with a BW of ≤500 g.

The predictors for the non-compliance to follow-up among very low birth weight infants in the Korean neonatal network

The critical need to emphasize preterm infant follow-up after neonatal intensive care unit (NICU) discharge assures early identification of and intervention for neurodevelopmental disability. The aims of this study were to observe the follow-up rates in high-risk follow-up clinics, and analyze factors associated with non-compliance to follow-up among very low birth weight (VLBW) infants. The data was prospectively collected for 3063 VLBW infants between January 2013 and December 2014 from 57 Korean neonatal network (KNN) centers at a corrected age of 18–24 months. Correlations among demographic data, clinical variables, and neonatal intensive care unit (NICU) volume (divided into 4 quartiles) with the occurrence of non-compliance were analyzed. The overall follow-up rate at the corrected age of 18–24 month was 65.4%. The follow-up rates were inversely related to birth weight and gestational age. Apgar score, hospital stay, maternal age, and maternal education were significantly different between the compliance and non-compliance groups. The follow-up rate was higher for mothers with chorioamnionitis, abnormal amniotic fluid, multiple pregnancy, and in vitro fertilization. Infants with respiratory distress syndrome, bronchopulmonary dysplasia, patent ductus arteriosus ligation, periventricular leukomalacia, and retinopathy of prematurity were more common in the compliance group. Follow-up rates showed significant differences according to NICU volume. Using multivariate logistic regression, high birth weight, low NICU volume, siblings, foreign maternal nationality and high 5 min APGAR scores were significant independent factors associated with the non-compliance of VLBW infants for follow-up at 18–24 months of age. This is the first nation-wide analysis of follow-up for VLBW infants in Korea. Understanding factors associated with failure of compliance could help improve the long-term follow-up rates and neurodevelopmental outcomes through early intervention.