Neurocognitive Outcomes at Age 2 Years After Neonatal Hypoglycemia in a Cohort of Participants From the hPOD Randomized Trial

Neonatal Hypoglycemia and Neurocognitive Function at School Age: A Prospective Cohort Study

OBJECTIVE

To determine the relationship between transient neonatal hypoglycemia in at-risk infants and neurocognitive function at 6-7 years of corrected age.

STUDY DESIGN

The pre-hPOD Study involved children born with at least one risk factor for neonatal hypoglycemia. Hypoglycemia was defined as ≥1 consecutive blood glucose concentrations <47 mg/dl (2.6 mmol/L), severe as <36 mg/dl (2.0 mmol/L), mild as 36 to <47 mg/dL (2.0 to <2.6 mmol/L), brief as 1 to 2 episodes, and recurrent as ≥3 episodes. At 6-7 y children were assessed for cognitive and motor function (NIH-Toolbox), learning, visual perception and behavior. The primary outcome was neurocognitive impairment, defined as >1 SD below the normative mean in ≥1 Toolbox tests. The eight secondary outcomes covered children's cognitive, motor, language, emotional-behavioral, and visual perceptual development. Primary and secondary outcomes were compared between children who did and did not experience neonatal hypoglycemia, adjusting for potential confounding by gestation, birthweight, sex and receipt of prophylactic dextrose gel (pre-hPOD intervention). Secondary analysis included assessment by severity and frequency of hypoglycemia.

RESULTS

Of 392 eligible children, 315 (80%) were assessed at school age (primary outcome, n=308); 47% experienced hypoglycemia. Neurocognitive impairment was similar between exposure groups (hypoglycemia 51% vs. 50% no hypoglycemia; aRD -4%, 95%CI -15%, 7%). Children with severe or recurrent hypoglycemia had worse visual motion perception and increased risk of emotional-behavioral difficulty.

CONCLUSION

Exposure to neonatal hypoglycemia was not associated with risk of neurocognitive impairment at school-age in at-risk infants, but severe and recurrent episodes may have adverse impacts.

Neonatal Hypoglycemia

Neonatal hypoglycemia (NH) is broadly defined as a low plasma glucose concentration that elicits hypoglycemia-induced impaired brain function. To date, no universally accepted threshold (reference range) for plasma glucose levels in newborns has been published, as data consistently indicate that neurologic responses to hypoglycemia differ at various plasma glucose concentrations. Infants at risk for NH include infants of diabetic mothers, small or large for gestational age, and premature infants. Common manifestations include jitteriness, poor feeding, irritability, and encephalopathy. Neurodevelopmental morbidities associated with NH include cognitive and motor delays, cerebral palsy, vision and hearing impairment, and poor school performance. This article offers a timely discussion of the state of the science of NH and recommendations for neonatal providers focused on early identification and disease prevention.

Relationship between Neonatal Cerebral Fuels and Neurosensory Outcomes at 3 Years in Well Babies: Follow-Up of the Glucose in Well Babies (GLOW) Study

INTRODUCTION

We sought to investigate if the availability of cerebral fuels soon after birth in healthy term babies was associated with developmental progress at 3 years of age.

METHODS

Healthy term babies had plasma glucose, lactate, and beta-hydroxybutyrate concentrations measured over the first 5 days. At 3 years, parents completed Ages and Stages (ASQ-3) questionnaires between December 2018 and August 2022. Developmental progress, analysed using structural equation modelling, was compared between children whose median fuel concentrations were above and below the mean neonatal concentrations of glucose (3.3 mmol/L) and total ATP-equivalents (140 mmol/L) in the first 48 h and over the first 5 days.

RESULTS

Sixty-four (96%) families returned completed questionnaires. We found no differences between developmental progress in children who had median neonatal plasma glucose concentrations <3.3 or ≥3.3 mmol/L in the first 48 h (estimated mean difference in ASQ scores -1.0, 95% confidence interval: -5.8, 3.7, p = 0.66) or 120 h (-3.7, -12.0, 4.6, p = 0.39]). There were also no differences for any other measures of cerebral fuels including total ATP above and below the median over 48 and 120 h, any plasma or interstitial glucose concentration <2.6 mmol/L, or cumulative duration of interstitial glucose concentration <2.6 mmol/L.

CONCLUSIONS

There was no detectable relationship between plasma concentrations of glucose, lactate, and beta-hydroxybutyrate soon after birth in healthy term babies and developmental progress at 3 years of age.

Are toddlers with neurosensory impairment more difficult to follow up? A secondary analysis of the hPOD follow-up study

OBJECTIVE

To describe strategies used to maximise follow-up after a neonatal randomised trial, how these differed for families of different ethnicity, socioeconomic status and urban versus rural residence and investigate relationships between the difficulty of follow-up and rate of neurosensory impairment.

METHOD

hPOD was a multicentre randomised trial assessing oral dextrose gel prophylaxis for neonatal hypoglycaemia. Follow-up at 2 years was conducted from 2017 to 2021. We analysed all recorded contacts between the research team and participants' families. Neurosensory impairment was defined as blindness, deafness, cerebral palsy, developmental delay or executive function impairment.

RESULTS

Of 1321 eligible participants, 1197 were assessed (91%) and 236/1194 (19.8%) had neurosensory impairment. Participants received a median of five contacts from the research team (range 1-23). Those from more deprived areas and specific ethnicities received more contacts, particularly home tracking visits and home assessments. Impairment was more common among participants receiving more contacts (relative risk 1.81, 95% CI 1.34 to 2.44 for ≥7 contacts vs <7 contacts), and among those assessed after the intended age (76/318, 23.9% if >25 months vs 160/876, 18.3% if ≤25 months).

CONCLUSIONS

Varied contact strategies and long timeframes are required to achieve a high follow-up rate. Without these, the sociodemographics of children assessed would not have been representative of the entire cohort, and the rate of neurosensory impairment would have been underestimated. To maximise follow-up after randomised trials, substantial effort and resources are needed to ensure that data are useful for clinical decision-making.

Neonatal hypoglycaemia

Low blood concentrations of glucose (hypoglycaemia) soon after birth are common because of the delayed metabolic transition from maternal to endogenous neonatal sources of glucose. Because glucose is the main energy source for the brain, severe hypoglycaemia can cause neuroglycopenia (inadequate supply of glucose to the brain) and, if severe, permanent brain injury. Routine screening of infants at risk and treatment when hypoglycaemia is detected are therefore widely recommended. Robust evidence to support most aspects of management is lacking, however, including the appropriate threshold for diagnosis and optimal monitoring. Treatment is usually initially more feeding, with buccal dextrose gel, followed by intravenous dextrose. In infants at risk, developmental outcomes after mild hypoglycaemia seem to be worse than in those who do not develop hypoglycaemia, but the reasons for these observations are uncertain. Here, the current understanding of the pathophysiology of neonatal hypoglycaemia and recent evidence regarding its diagnosis, management, and outcomes are reviewed. Recommendations are made for further research priorities.

Early Feeding for the Prevention of Neonatal Hypoglycaemia: A Systematic Review and Meta-Analysis

BACKGROUND

Poor feeding, among other factors, predisposes neonates to hypoglycaemia. Early feeding is widely recommended to prevent hypoglycaemia in those at risk, but the effectiveness of this is uncertain. This review aimed to summarise and analyse the evidence on the effectiveness of early feeding for prevention of neonatal hypoglycaemia.

METHODS

Four databases and three clinical trial registries were searched from inception to May 24, 2023. Published and unpublished randomised controlled trials (RCTs), quasi-RCTs, cluster randomised trials, non-randomised studies of interventions, and observational studies with comparison groups were considered for inclusion with no language or publication date restrictions. We included studies of neonates who were fed early (within 60 min of birth or study defined) versus delayed. Study quality was assessed using the Cochrane Risk of Bias 1 tool or Effective Public Health Practice Project Quality Assessment tool. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. RevMan 5.4.1 or R was used to synthesise results in random-effects meta-analyses. This review was registered prospectively with PROSPERO (CRD42022378904).

RESULTS

A total of 175,392 participants were included across 19 studies, of which two were RCTs, 14 cohort studies, two cross-sectional studies, and one a case-control study. Most studies (13/19) were conducted in low- or lower-middle-income countries. Early feeding may be associated with reduced neonatal hypoglycaemia (four cohort studies, 744 infants, odds ratio [OR] 0.19 (95% CI: 0.10-0.35), p < 0.00001, I2 = 44%) and slightly reduced duration of initial hospital stay (one cohort study, 1,673 infants, mean difference: -0.20 days [95% CI: -0.31 to -0.09], p = 0.0003), but the evidence is very uncertain. One RCT found early feeding had little or no effect on the risk of neonatal mortality, but three cohort studies found early feeding may be associated with reduced risk (136,468 infants, OR 0.51 [95% CI: 0.37-0.72]; low certainty evidence; p <0.0001; I2 = 54%).

CONCLUSION

We found that early feeding may reduce the incidence of neonatal hypoglycaemia, but the evidence is very uncertain. Given its many other benefits, early feeding should continue to be recommended. This review was primarily funded by the Aotearoa Foundation and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) of the National Institutes of Health.

Systematic review of guidelines on neonatal hypoglycemia

OBJECTIVE

In recent years, a series of clinical guidelines on neonatal hypoglycemia have been developed in different countries and regions. This systematic review was aimed at providing evidence for clinical decision-making and providing ideas for future research by comparatively analyzing the contents of various guidelines.

METHODS

A multilateral approach was used, including comprehensive literature searches and online research. The retrieved studies were screened by two independent reviewers according to our inclusion criteria. The two reviewers independently extracted the descriptive data. Four appraisers assessed the guidelines using the AGREE-II instrument.

RESULTS

Ten clinical guidelines on neonatal hypoglycemia were included, with a mean score of 45.28%-83.45% in six domains. The guidelines are relatively consistent in their recommendations on clinical symptoms of neonatal hypoglycemia, but different in risk factors, preventive measures, thresholds for clinical management of hypoglycemia, target glucose ranges for its control, and pharmacotherapy.

CONCLUSION

By summarising the recommendations in the guidelines on neonatal hypoglycemia, we found that blood glucose values were not the only observational indicator, and other indicators (e.g., ketone bodies, lactate) related to glucose metabolism should also be considered for a comprehensive assessment. There is still a lack of consensus on thresholds for the clinical management of hypoglycemia and target glucose ranges for its control, and the recommendations on its pharmacotherapy are rather simple and sketchy. In the future, more high-quality studies are required to further improve the early identification of neonatal hypoglycemia and intervention strategies against it.

Prenatal air pollution, fetal β-cell dysfunction and neurodevelopmental delay

BACKGROUND

Emerging evidence has reported significant associations of prenatal air pollution exposure with neurodevelopmental delay in offspring. Sensitive exposure windows and the modifiable factor remain elusive.

OBJECTIVE

We aim to identify sensitive windows of air pollution during pregnancy on neurodevelopmental delay, and examine whether cord blood C-peptide mediates the relationship.

METHODS

This study included 7438 mother-newborn pairs in Hefei, China, from 2015 to 2021. Weekly exposure to particulate matter of aerodynamic diameter <2.5 µm, 10 µm (PM2.5, PM10), nitrogen dioxide (NO2) and carbon monoxide (CO) was estimated at regulatory air monitoring stations in Hefei. Denver Developmental Screening Test-II and the Gesell Developmental Schedules were applied to assess the neurodevelopmental delay in children 6-36 mon of age. Distributed lag nonlinear models examined sensitive time windows of prenatal air pollutants exposure. Mediation analysis estimated the mediating role of cord blood C-peptide.

RESULTS

The sensitive PM2.5, PM10, NO2, and CO exposure windows associated with neurodevelopmental delay were throughout pregnancy. Weekly air pollutants exposure was related to higher neurodevelopmental delay risks [cumulative odds ratio (OR): 1.40(1.29,1.53) in PM2.5 (per 10 μg/m3), 1.40(1.28,1.53) in PM10 (per 10 μg/m3), 1.41(1.30,1.52) in CO (per 0.1 mg/m3), and 1.49(1.29,1.72) in NO2 (per 5 μg/m3)]. Mediation analysis indicated 18.3 % contributions of cord C-peptide to the relationship [average mediation effect: 0.04(0.01.0.06); average direct effect: 0.15(0.07.0.25)].

CONCLUSIONS

Exposure to air pollution throughout pregnancy is linked to neurodevelopmental delay mediated by poorer fetal β-cell function. Screening and treatment of abnormal glucose metabolism in infants could benefit the prevention of air pollution-associated neurodevelopment delay.

Delivery room glucose to reduce the risk of admission hypoglycemia in preterm infants: a systematic literature review

AIMS

In order to mitigate early hypoglycemia in preterm infants, some clinicians have recently explored interventions such as delivery room commencement of dextrose infusions or delivery room administration of buccal dextrose gel. This review aimed to systematically investigate the literature regarding the provision of delivery room (prior to admission) parenteral glucose as a method to reduce the risk of initial hypoglycemia (measured at the time of NICU admission blood testing) in preterm infants.

MATERIALS AND METHODS

Using PRISMA guidelines a literature search (May 2022) was conducted using PubMed, Embase, Scopus, Cochrane Library, OpenGrey, and Prospero databases. The clinicaltrials.gov database was searched for possible completed/ongoing clinical trials. Studies that included moderate preterm (≤33⁺⁶ weeks) or younger birth gestations or very low birth weight (or smaller) infants, and that administered parenteral glucose in the delivery room were included. The literature was appraised via data extraction, narrative synthesis, and critical review of the study data.

RESULTS

A total of five studies (published 2014-2022) were eligible for inclusion (three before-after "quasi-experimental" studies, one retrospective cohort study, and one case-control study). Most included studies used intravenous dextrose as the intervention. Individual study effects (odds ratios) favored the intervention in all included studies. It was felt that the low number of studies, the variability in study design, and the nonadjustment for confounding co-interventions (co-exposures) precluded a meta-analysis. Quality assessment of the studies revealed a spectrum of bias from low to high risk, however, most studies had moderate to high risk of bias, and their direction of bias favored the intervention.

CONCLUSIONS

This extensive search and systematic appraisal of the literature indicates that there exists few studies (these are low grade and at moderate to high risk of bias) for the interventions of either intravenous or buccal dextrose given in the delivery room. It is not clear if these interventions impact on rates of early (NICU admission) hypoglycemia in these preterm infants. Obtaining intravenous access in the delivery room is not guaranteed and can be difficult in these small infants. Future research should consider various routes for commencing delivery room glucose in these preterm infants and should take the form of randomized controlled trials.

A quality improvement initiative for neonatal hypoglycemia screening and management in a level III neonatal intensive care unit

OBJECTIVE

To bring screening and management of neonatal hypoglycemia in alignment with the 2011 AAP hypoglycemia clinical report METHODS: A multidisciplinary team developed a quality improvement initiative for neonatal hypoglycemia in neonates ≥35 weeks gestational age in a Level III neonatal intensive care unit between July 2020 and December 2021. A key driver diagram identified interventions for plan-do-study-act testing with corresponding measures to implement a hypoglycemia management protocol and improve adherence to AAP guidelines.

RESULTS

Time to first blood glucose measurement increased from 49.8 to 122.7 min of life and time to first enteral feed decreased from 14.2 to 3.6 h of life. Neonates receiving intravenous dextrose decreased from 97.1 to 24.7% and discharge rates as a mother-neonate dyad increased from 35 to 62.4%.

CONCLUSIONS

Adherence to the AAP guidelines improved during testing and implementation of a hypoglycemia protocol and was associated with an increased mother-neonate dyad discharge rate.

Application of the screening test principles to screening for neonatal hypoglycemia

Severe and prolonged neonatal hypoglycemia can cause brain injury, while the long-term consequences of mild or transitional hypoglycemia are uncertain. As neonatal hypoglycemia is often asymptomatic it is routine practice to screen infants considered at risk, including infants of mothers with diabetes and those born preterm, small or large, with serial blood tests over the first 12-24 h after birth. However, to prevent brain injury, the gold standard would be to determine if an infant has neuroglycopenia, for which currently there is not a diagnostic test. Therefore, screening of infants at risk for neonatal hypoglycemia with blood glucose monitoring does not meet several screening test principles. Specifically, the long-term neurodevelopmental outcomes of transient neonatal hypoglycemia are not well understood and there is no direct evidence from randomized controlled trials that treatment of hypoglycemia improves long-term neurodevelopmental outcomes. There have been no studies that have compared the long-term neurodevelopmental outcomes of at-risk infants screened for neonatal hypoglycemia and those not screened. However, screening infants at risk of hypoglycemia and treating those with hypoglycaemic episodes to maintain the blood glucose concentrations ≥2.6 mmol/L appears to preserve cognitive function compared to those without episodes. This narrative review explores the evidence for screening for neonatal hypoglycemia, the effectiveness of blood glucose screening as a screening test and recommend future research areas to improve screening for neonatal hypoglycemia. Screening babies at-risk of neonatal hypoglycemia continues to be necessary, but as over a quarter of all infants may be screened for neonatal hypoglycemia, further research is urgently needed to determine the optimal method of screening and which infants would benefit from screening and treatment.

Effects of antenatal corticosteroids on neonatal blood glucose fluctuation in late-preterm infants

OBJECTIVE

To evaluate the effects of antenatal corticosteroids (ACS) on blood glucose fluctuations in late-preterm neonates.

METHODS

A retrospective study was performed on 236 neonates with gestational age of 34⁺⁰ to 36⁺⁶ weeks who were admitted to the neonatology department of a tertiary general hospital in China's Zhejiang Province between April 2020 and February 2022. The neonates were divided into three groups: complete course, partial course, and control. Primary outcome was the neonatal blood glucose levels within the first 48 h of life.

RESULTS

134 (56.8%) newborns were exposed to a complete course of ACS, 56 (23.7%) had a to a partial course of ACS, and 46 (19.5%) had no exposure to ACS. The patients in the complete course group had the highest proportion of neonatal hypoglycemia (16.4% vs. 3.6% and 6.5%).The patients exposed to a complete course of dexamethasone had significantly lower blood glucose levels within 12 h of birth than the control group, although no significant differences were observed after 24 h. Differences in blood glucose levels were more significant among male infants, although blood glucose curves of the male and female infants remained close to the overall trend.

CONCLUSIONS

Blood glucose levels in late-preterm neonates may decrease after ACS administration, especially after exposure to a complete course. The effects are more pronounced in the first 12 h of life, with males being more severely affected; however, the effects on blood glucose levels were not significant 24 h after birth. This can provide a reference for future clinical studies.