Strategies to improve neurodevelopmental outcomes in babies at risk of neonatal hypoglycaemia

Pathophysiology from preconception, during pregnancy, and beyond

Gestational diabetes is the most common medical complication in pregnancy. Historically, gestational diabetes was considered a pregnancy complication involving treatment of rising glycaemia late in the second trimester. However, recent evidence challenges this view. Pre-pregnancy and pregnancy-specific factors influence gestational glycaemia, with open questions regarding roles of non-glycaemic factors in the aetiology and consequences of gestational diabetes. Varying patterns of insulin secretion and resistance in early and late pregnancy underlie a heterogeneity of gestational diabetes in the timing and pathophysiological subtypes with clinical implications: early gestational diabetes and insulin resistant gestational diabetes subtypes are associated with a higher risk of pregnancy complications. Metabolic perturbations of early gestational diabetes can affect early placental development, affecting maternal metabolism and fetal development. Fetal hyperinsulinaemia can affect the development of multiple fetal tissues, with short-term and long-term consequences. Pregnancy complications are prevented by managing glycaemia in early and late pregnancy in some, but not all women with gestational diabetes. A better understanding of the pathophysiology and heterogeneity of gestational diabetes will help to develop novel management approaches with focus on improved prevention of maternal and offspring short-term and long-term complications, from pre-conception, throughout pregnancy, and beyond.

Dextrose gel prophylaxis for neonatal hypoglycaemia and neurocognitive function at early school age: a randomised dosage trial

OBJECTIVE

To investigate the effect of different doses of prophylactic dextrose gel on neurocognitive function and health at 6-7 years.

DESIGN

Early school-age follow-up of the pre-hPOD (hypoglycaemia Prevention with Oral Dextrose) study.

SETTING

Schools and communities.

PATIENTS

Children born at ≥35 weeks with ≥1 risk factor for neonatal hypoglycaemia: maternal diabetes, small or large for gestational age, or late preterm.

INTERVENTIONS

Four interventions commencing at 1 hour of age: dextrose gel (40%) 200 mg/kg; 400 mg/kg; 200 mg/kg and 200 mg/kg repeated before three feeds (800 mg/kg); 400 mg/kg and 200 mg/kg before three feeds (1000 mg/kg); compared with equivolume placebo (combined for analysis).

MAIN OUTCOMES MEASURES

Toolbox cognitive and motor batteries, as well as tests of motion perception, numeracy and cardiometabolic health, were used. The primary outcome was neurocognitive impairment, defined as a standard score of more than 1 SD below the age-corrected mean on one or more Toolbox tests.

FINDINGS

Of 392 eligible children, 309 were assessed for the primary outcome. There were no significant differences in the rate of neurocognitive impairment between those randomised to placebo (56%) and dextrose gel (200 mg/kg 46%: adjusted risk difference (aRD)=-14%, 95% CI -35%, 7%; 400 mg/kg 48%: aRD=-7%, 95% CI -27%, 12%; 800 mg/kg 45%: aRD=-14%, 95% CI -36%, 9%; 1000 mg/kg 50%: aRD=-8%, 95% CI -29%, 13%). Children exposed to any dose of dextrose gel (combined), compared with placebo, had a lower risk of motor impairment (3% vs 14%, aRD=-11%, 95% CI -19%, -3%) and higher mean (SD) cognitive scores (106.0 (15.3) vs 101.1 (15.7), adjusted mean difference=5.4, 95% CI 1.8, 8.9).

CONCLUSIONS

Prophylactic neonatal dextrose gel did not alter neurocognitive impairment at early school age but may have motor and cognitive benefits. Further school-age follow-up studies are needed.

Intrapartum maternal glycaemic control for the prevention of neonatal hypoglycaemia: a systematic review and meta-analysis

BACKGROUND

Neonatal hypoglycaemia is the most common metabolic disorder in infants, and may be influenced by maternal glycaemic control. This systematic review evaluated the effect of intrapartum maternal glycaemic control on neonatal hypoglycaemia.

METHODS

We included randomised controlled trials (RCTs), quasi-RCTs, non-randomised studies of interventions, and cohort or case-control studies that examined interventions affecting intrapartum maternal glycaemic control compared to no or less stringent control. We searched four databases and three trial registries to November 2023. Quality assessments used Cochrane Risk of Bias 1 or the Effective Public Health Practice Project Quality Assessment Tool. Certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Meta-analysis was performed using random-effects models analysed separately for women with or without diabetes. The review was registered prospectively on PROSPERO (CRD42022364876).

RESULTS

We included 46 studies of women with diabetes and five studies of women without diabetes: one RCT, 32 cohort and 18 case-control studies (11,273 participants). For women with diabetes, the RCT showed little to no difference in the incidence of neonatal hypoglycaemia between tight versus less tight intrapartum glycaemic control groups (76 infants, RR 1.00 (0.45, 2.24), p = 1.00, low certainty evidence). However, 11 cohort studies showed tight intrapartum glycaemic control may reduce neonatal hypoglycaemia (6,152 infants, OR 0.44 (0.31, 0.63), p < 0.00001, I2 = 58%, very low certainty evidence). For women without diabetes, there was insufficient evidence to determine the effect of tight intrapartum glycaemic control on neonatal hypoglycaemia.

CONCLUSIONS

Very uncertain evidence suggests that tight intrapartum glycaemic control may reduce neonatal hypoglycaemia in infants of women with diabetes. High-quality RCTs are required.

Diazoxide for Severe or Recurrent Neonatal Hypoglycemia: A Randomized Clinical Trial

Importance

Neonatal hypoglycemia is an important preventable cause of neurodevelopmental impairment, but there is a paucity of evidence to guide treatment.

Objective

To evaluate whether early, low-dose oral diazoxide for severe or recurrent neonatal hypoglycemia reduces time to resolution of hypoglycemia.

Design, Setting, and Participants

This 2-arm, placebo-controlled randomized clinical trial was conducted from May 2020 to February 2023 in tertiary neonatal units at 2 New Zealand hospitals. Participants were neonates born at 35 or more weeks' gestation and less than 1 week of age with severe hypoglycemia (blood glucose concentration <22 mg/dL or <36 mg/dL despite 2 doses of dextrose gel) or recurrent hypoglycemia (≥3 episodes of a blood glucose concentration <47 mg/dL within 48 hours).

Interventions

Newborns were randomized 1:1 to receive diazoxide suspension (loading dose, 5 mg/kg; maintenance, 1.5 mg/kg every 12 hours) or placebo, titrated per protocol.

Main Outcome and Measures

The primary outcome was time to resolution of hypoglycemia, defined as enteral bolus feeding without intravenous fluids and normoglycemia (blood glucose concentration of 47-98 mg/dL) for at least 24 hours, compared between groups using adjusted Cox proportional hazards regression. Hazard ratios adjusted for stratification variables and gestation length are reported. Prespecified secondary outcomes, including number of blood glucose tests and episodes of hypoglycemia, duration of hypoglycemia, and time to enteral bolus feeding and weaning from intravenous fluids, were compared by generalized linear models. Newborns were followed up for at least 2 weeks.

Results

Of 154 newborns screened, 75 were randomized and 74 with evaluable data were included in the analysis (mean [SD] gestational age for the full cohort, 37.6 [1.6] weeks), 36 in the diazoxide group and 38 in the placebo group. Baseline characteristics were similar: in the diazoxide group, mean (SD) gestational age was 37.9 (1.6) weeks and 26 (72%) were male; in the placebo group, mean (SD) gestational age was 37.4 (1.5) weeks and 27 (71%) were male. There was no significant difference in time to resolution of hypoglycemia (adjusted hazard ratio [AHR], 1.39; 95% CI, 0.84-2.23), possibly due to increased episodes of elevated blood glucose concentration and longer time to normoglycemia in the diazoxide group. Resolution of hypoglycemia, when redefined post hoc as enteral bolus feeding without intravenous fluids for at least 24 hours with no further hypoglycemia, was reached by more newborns in the diazoxide group (AHR, 2.60; 95% CI, 1.53-4.46). Newborns in the diazoxide group had fewer blood glucose tests (adjusted count ratio [ACR], 0.63; 95% CI, 0.56-0.71) and episodes of hypoglycemia (ACR, 0.32; 95% CI, 0.17-0.63), reduced duration of hypoglycemia (adjusted ratio of geometric means [ARGM], 0.18; 95% CI, 0.06-0.53), and reduced time to enteral bolus feeding (ARGM, 0.74; 95% CI, 0.58-0.95) and weaning from intravenous fluids (ARGM, 0.72; 95% CI, 0.60-0.87). Only 2 newborns (6%) treated with diazoxide had hypoglycemia after the loading dose compared with 20 (53%) with placebo.

Conclusions and Relevance

In this randomized clinical trial, early treatment of severe or recurrent neonatal hypoglycemia with low-dose oral diazoxide did not reduce time to resolution of hypoglycemia but reduced time to enteral bolus feeding and weaning from intravenous fluids, duration of hypoglycemia, and frequency of blood glucose testing compared with placebo.

Trial Registration

ANZCTR.org.au Identifier: ACTRN12620000129987.

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 1 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 1-2 episodes, and recurrent as ≥3 episodes. At 6-7 years 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 8 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.

TRIAL REGISTRATION

Hypoglycemia Prevention in Newborns with Oral Dextrose: the Dosage Trial (pre-hPOD Study): ACTRN12613000322730.

Proposed Screening for Congenital Hyperinsulinism in Newborns: Perspective from a Neonatal-Perinatal Medicine Group

This perspective work by academic neonatal providers is written specifically for the audience of newborn care providers and neonatologists involved in neonatal hypoglycemia screening. Herein, we propose adding a screen for congenital hyperinsulinism (CHI) by measuring glucose and ketone (i.e., β-hydroxybutyrate (BOHB)) concentrations just prior to newborn hospital discharge and as close to 48 h after birth as possible, at the same time that the mandated state Newborn Dried Blood Spot Screen is obtained. In the proposed protocol, we do not recommend specific metabolite cutoffs, as our primary objective is to simply highlight the concept of screening for CHI in newborns to newborn caregivers. The premise for our proposed screen is based on the known effect of hyperinsulinism in suppressing ketogenesis, thereby limiting ketone production. We will briefly discuss genetic CHI, other forms of neonatal hypoglycemia, and their shared mechanisms; the mechanism of insulin regulation by functional pancreatic islet cell membrane KATP channels; adverse neurodevelopmental sequelae and brain injury due to missing or delaying the CHI diagnosis; the principles of a good screening test; how current neonatal hypoglycemia screening programs do not fulfill the criteria for being effective screening tests; and our proposed algorithm for screening for CHI in newborns.

Investigating behaviour from early- to mid-childhood and its association with academic outcomes in a cohort of children born at risk of neonatal hypoglycaemia

High rates of academic underachievement at 9-10 years have been identified in children born at risk of neonatal hypoglycaemia. This study investigated the stability of behaviour from early to mid-childhood and how this relates to academic outcomes in children born with at least one risk factor of neonatal hypoglycaemia in Aotearoa, New Zealand. Behaviour data was collected using the Bayley Scales of Infant and Toddler Development, Child Behaviour Checklist 1.5-5, and the Strengths and Difficulties Questionnaire for 466 children (52 % male; 27 % Māori, 60 % New Zealand European, 2 % Pacific, 11 % Other) at multiple timepoints between ages 2 and 10 years. Academic data was collected at 9-10 years using the e-asTTle online learning and assessment tool. Findings revealed a link between early childhood behaviour and academic outcomes could be detected as early as age 2, suggesting that identifying and addressing early behavioural issues in children at risk of neonatal hypoglycaemia could aid in targeted interventions.

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.

Infants Eligible for Neonatal Hypoglycemia Screening: A Systematic Review

Importance

Neonatal hypoglycemia is common, occurring in up to 50% of infants at risk for hypoglycemia (infant of diabetic mother [IDM], small for gestational age [SGA], large for gestational age [LGA], and preterm) and is associated with long-term neurodevelopmental impairment. Guidelines recommend screening infants at risk of hypoglycemia. The proportion of infants who require screening for neonatal hypoglycemia is unknown.

Objective

To determine the proportion of infants eligible for neonatal hypoglycemia screening using criteria from the highest-scoring critically appraised clinical guideline.

Design, Setting, and Participants

This systematic review of the literature was conducted to identify clinical practice guidelines for neonatal hypoglycemia and took place at a tertiary maternity hospital in Auckland, New Zealand. Eligible guidelines were critically appraised using the Appraisal of Guidelines for Research and Evaluation II tool. Using screening criteria extracted from the highest-scoring guideline, the proportion of infants eligible for neonatal hypoglycemia screening was determined in a retrospective observational cohort study of infants born January 1, 2004, to December 31, 2018. Data were analyzed by logistic regression. Infant participants were included if gestational age was 35 weeks or more, birth weight was 2000 g or more, and they were not admitted to a neonatal intensive care unit less than 1 hour after birth. The data were analyzed from November 2022 through February 2023. A total of 101 372 infants met the inclusion criteria.

Exposure

Risk factors for neonatal hypoglycemia.

Main Outcome

Proportion of infants eligible for neonatal hypoglycemia screening.

Results

The study team screened 2366 abstracts and 18 guidelines met inclusion criteria for appraisal. There was variability in the assessed quality of guidelines and a lack of consensus between screening criteria. The highest-scoring guideline defined screening criteria as: IDM, preterm (less than 37 weeks' gestation), SGA (less than 10th percentile), birth weight of less than 2500 g or more than 4500 g, LGA (more than 90th percentile), or gestational age more than 42 weeks. A total of 101 372 infants met criteria for inclusion in the cohort study; median (IQR) gestational age was 39 (38-40) weeks and 51% were male. The overall proportion of infants eligible for screening was 26.3%. There was an increase in the proportion of eligible infants from 25.6% to 28.5% over 15 years, which was not statistically significant after adjustment for maternal age, body mass index, ethnicity, and multiple pregnancy (odds ratio, 0.99; 95% CI, 0.93-1.03; change in proportion per year).

Conclusion

A systematic review found that practice guidelines providing recommendations for clinical care of neonatal hypoglycemia were of variable quality with is a lack of consensus regarding definitions for infants at risk for hypoglycemia. In the cohort study, one-quarter of infants were eligible for hypoglycemia screening. Further research is required to identify which infants may benefit from neonatal hypoglycemia screening.

Development and clinical application of a stability-indicating chromatography technique for the quantification of diazoxide

Diazoxide is a potential candidate for the treatment of transitional hypoglycaemia in infants. A clinical trial is currently underway to investigate whether low-dose oral diazoxide is beneficial for severe or recurrent transitional neonatal hypoglycaemia (the NeoGluCO Study, registration ANZCTR12620000129987). The present study aimed to develop and validate the parameters for quantifying diazoxide from neonatal plasma samples, and to assess the stability of extemporaneously prepared diazoxide suspensions to support the NeoGluCO Study. To determine the plasma concentration of diazoxide, a protein precipitation mediated extraction protocol was developed, which demonstrated >94% diazoxide extraction recoveries from all samples. The method was linear over the range of 0.2-40 μg/mL (R2 > 0.9994) with a limit of quantification of 0.2 μg/mL. Accuracy of the method was within 97-106% with relative standard deviation < 6% for all samples. Diazoxide-plasma samples were stable for up to three months at -20 °C and up to 48 h when stored in the auto-sampler. Samples were stable for up to two freeze-thaw cycles, with further cycles compromising stability of diazoxide in plasma. The developed method was applied to determine chemical stability of the extemporaneously prepared diazoxide suspensions. These were stable at both 2-8 °C and 25 °C/60% RH, with 98% of diazoxide remaining after 35 days in both storage conditions. Diazoxide was successfully quantified from plasma collected from six neonates enrolled in the NeoGluCO Study, using the developed protocol. Overall, an efficient and reproducible extraction protocol was developed and validated for the estimation of diazoxide from human plasma.

Development of a prediction model for neonatal hypoglycemia risk factors: a retrospective study

Background

It's challenging for healthcare workers to detect neonatal hypoglycemia due to its rapid progression and lack of aura symptoms. This may lead to brain function impairment for the newborn, placing a significant care burden on the family and creating an economic burden for society. Tools for early diagnosis of neonatal hypoglycemia are lacking. This study aimed to identify newborns at high risk of developing neonatal hypoglycemia early by developing a risk prediction model.

Methods

Using a retrospective design, pairs (470) of women and their newborns in a tertiary hospital from December 2021 to September 2022 were included in this study. Socio-demographic data and clinical data of mothers and newborns were collected. Univariate and multivariate logistic regression were used to screen optimized factors. A neonatal hypoglycemia risk nomogram was constructed using R software, and the calibration curve and receiver operator characteristic curve (ROC) was utilized to evaluate model performance.

Results

Factors integrated into the prediction risk nomogram were maternal age (odds ratio [OR] =1.10, 95% CI: 1.04, 1.17), fasting period (OR=1.07, 95% CI: 1.03, 1.12), ritodrine use (OR=2.00, 95% CI: 1.05, 3.88), gestational diabetes mellitus (OR=2.13, 95% CI: 1.30, 3.50), gestational week (OR=0.80, 95% CI: 0.66, 0.96), fetal distress (OR=1.76, 95% CI: 1.11, 2.79) and neonatal body mass index (OR=1.50, 95% CI: 1.24, 1.84). The area under the curve (AUC) was 0.79 (95% confidence interval [CI]: 0.75, 0.82), specificity was 0.82, and sensitivity was 0.62.

Conclusion

The prediction model of this study demonstrated good predictive performance. The development of the model identifies advancing maternal age, an extended fasting period before delivery, ritodrine use, gestational diabetes mellitus diagnosis, fetal distress diagnosis and an increase in neonatal body mass index increase the probability of developing neonatal hypoglycemia, while an extended gestational week reduces the probability of developing neonatal hypoglycemia.

Metabolic acidosis during continuous glucagon therapy for neonatal hypoglycemia

Objectives

Refractory neonatal hypoglycemia may be treated with glucagon infusions, which have been associated with thrombocytopenia and hyponatremia. After anecdotally noting metabolic acidosis during glucagon therapy in our hospital, an outcome not previously reported in the literature, we aimed to quantify occurrence of metabolic acidosis (base excess >-6) as well as thrombocytopenia and hyponatremia during treatment with glucagon.

Methods

We performed a single-centre retrospective case series. Descriptive statistics were used and subgroups compared with Chi-Square, Fisher's Exact Test, and Mann-Whitney U testing.

Results

Sixty-two infants (mean birth gestational age 37.2 weeks, 64.5% male) were treated with continuous glucagon infusions for median 10 days during the study period. 41.2% were preterm, 21.0% were small for gestational age, and 30.6% were infants of diabetic mothers. Metabolic acidosis was seen in 59.6% and was more common in infants who were not born to diabetic mothers (75% versus 24% in infants of diabetic mothers, P<0.001). Infants with versus without metabolic acidosis had lower birth weights (median 2,743 g versus 3,854 g, P<0.01) and were treated with higher doses of glucagon (0.02 versus 0.01 mg/kg/h, P<0.01) for a longer duration (12.4 versus 5.9 days, P<0.01). Thrombocytopenia was diagnosed in 51.9% of patients.

Conclusions

In addition to thrombocytopenia, metabolic acidosis of unclear etiology appears to be very common with glucagon infusions for neonatal hypoglycemia, especially in lower birth weight infants or those born to mothers without diabetes. Further research is needed to elucidate causation and potential mechanisms.

Oral diazoxide versus placebo for severe or recurrent neonatal hypoglycaemia: Neonatal Glucose Care Optimisation (NeoGluCO) study - a randomised controlled trial

INTRODUCTION

Infants with severe or recurrent transitional hypoglycaemia continue to have high rates of adverse neurological outcomes and new treatment approaches are needed that target the underlying pathophysiology. Diazoxide is one such treatment that acts on the pancreatic β-cell in a dose-dependent manner to decrease insulin secretion.

METHODS AND ANALYSIS

Phase IIB, double-blind, two-arm, parallel, randomised trial of diazoxide versus placebo in neonates ≥35 weeks' gestation for treatment of severe (blood glucose concentration (BGC)<1.2 mmol/L or BGC 1.2 to <2.0 mmol/L despite two doses of buccal dextrose gel and feeding in a single episode) or recurrent (≥3 episodes <2.6 mmol/L in 48 hours) transitional hypoglycaemia. Infants are loaded with diazoxide 5 mg/kg orally and then commenced on a maintenance dose of 1.5 mg/kg every 12 hours, or an equal volume of placebo. The intervention is titrated from the third maintenance dose by protocol to target BGC in the range of 2.6-5.4 mmol/L. The primary outcome is time to resolution of hypoglycaemia, defined as the first point at which the following criteria are met concurrently for ≥24 hours: no intravenous fluids, enteral bolus feeding and normoglycaemia. Groups will be compared for the primary outcome using Cox's proportional hazard regression analysis, expressed as adjusted HR with a 95% CI.

ETHICS AND DISSEMINATION

This trial has been approved by the Health and Disability Ethics Committees of New Zealand (19CEN189). Findings will be disseminated in peer-reviewed journals, to clinicians and researchers at local and international conferences and to the public.

TRIAL REGISTRATION NUMBER

ACTRN12620000129987.

Association of Neonatal Hypoglycemia With Academic Performance in Mid-Childhood

IMPORTANCE

Neonatal hypoglycemia is associated with increased risk of poor executive and visual-motor function, but implications for later learning are uncertain.

OBJECTIVE

To test the hypothesis that neonatal hypoglycemia is associated with educational performance at age 9 to 10 years.

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort study of moderate to late preterm and term infants born at risk of hypoglycemia. Blood and masked interstitial sensor glucose concentrations were measured for up to 7 days. Infants with hypoglycemic episodes (blood glucose concentration <47 mg/dL [2.6 mmol/L]) were treated to maintain a blood glucose concentration of at least 47 mg/dL. Six hundred fourteen infants were recruited at Waikato Hospital, Hamilton, New Zealand, in 2006-2010; 480 were assessed at age 9 to 10 years in 2016-2020.

EXPOSURES

Hypoglycemia was defined as at least 1 hypoglycemic event, representing the sum of nonconcurrent hypoglycemic and interstitial episodes (sensor glucose concentration <47 mg/dL for ≥10 minutes) more than 20 minutes apart.

MAIN OUTCOMES AND MEASURES

The primary outcome was low educational achievement, defined as performing below or well below the normative curriculum level in standardized tests of reading comprehension or mathematics. There were 47 secondary outcomes related to executive function, visual-motor function, psychosocial adaptation, and general health.

RESULTS

Of 587 eligible children (230 [48%] female), 480 (82%) were assessed at a mean age of 9.4 (SD, 0.3) years. Children who were and were not exposed to neonatal hypoglycemia did not significantly differ on rates of low educational achievement (138/304 [47%] vs 82/176 [48%], respectively; adjusted risk difference, -2% [95% CI, -11% to 8%]; adjusted relative risk, 0.95 [95% CI, 0.78-1.15]). Children who were exposed to neonatal hypoglycemia, compared with those not exposed, were significantly less likely to be rated by teachers as being below or well below the curriculum level for reading (68/281 [24%] vs 49/157 [31%], respectively; adjusted risk difference, -9% [95% CI, -17% to -1%]; adjusted relative risk, 0.72 [95% CI, 0.53-0.99; P = .04]). Groups were not significantly different for other secondary end points.

CONCLUSIONS AND RELEVANCE

Among participants at risk of neonatal hypoglycemia who were screened and treated if needed, exposure to neonatal hypoglycemia compared with no such exposure was not significantly associated with lower educational achievement in mid-childhood.

Actual incidence of severe neonatal hypoglycemia in non-risk term neonates: A 10 year survey of all cases in Toyama Prefecture, Japan

BACKGROUND

Severe neonatal hypoglycemia may cause irreversible neurological sequelae. Although blood glucose (BG) screening in term neonates without risk factors for hypoglycemia (non-risk neonates) is not recommended in the current guidelines, severe hypoglycemia can occur in such neonates. To evaluate the necessity of BG screening in non-risk neonates, it is important to determine the accurate incidence of severe hypoglycemia in those neonates.

METHODS

We conducted a 10 year survey of all normal-weight term neonates diagnosed with severe neonatal hypoglycemia who were treated at secondary- and tertiary-level neonatal centers in Toyama Prefecture, Japan, between January 2011 and December 2020.

RESULTS

During the study period, 11 cases of severe neonatal hypoglycemia (six of which occurred in non-risk neonates) were identified. The overall incidence of severe hypoglycemia was 1 in 5,827 normal-weight term births, and the incidence in non-risk neonates was 1 in 10 682 normal-weight term births. All of the cases in non-risk neonates were diagnosed as hyperinsulinemic hypoglycemia.

CONCLUSIONS

This is the first population-based study to have identified the actual incidence of severe pathological neonatal hypoglycemia in non-risk neonates. The incidence was not low compared with those of the newborn screening disorders, justifying the necessity of BG screening even in non-risk neonates.

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.

Glucagon for Neonatal Hypoglycaemia: Systematic Review and Meta-Analysis

INTRODUCTION

Glucagon is often used in neonatal hypoglycaemia, but its effects have not been systematically assessed. We undertook a systematic review to determine the efficacy and safety of glucagon treatment for neonatal hypoglycaemia.

METHODS

We searched MEDLINE, CINAHL, EMBASE, and CENTRAL from inception until May 2021. We included studies that reported one or more prespecified outcomes and compared glucagon with placebo or no glucagon. Studies were excluded if the majority (>70%) of participants were >1 month of age. Two authors independently extracted data. We used ROB-2/modified ROBINS-I to assess risk of bias, GRADE for certainty of evidence, and RevMan for meta-analysis.

RESULTS

100 studies were screened, 37 reviewed in full, and seven single-arm non-randomised intervention studies, involving 348 infants, were included (no trials). Data were insufficient to undertake meta-analysis of the critical outcomes (time to blood glucose normalization, recurrent hypoglycaemia, neurocognitive impairment). In 3 studies, ≥80% of neonates achieved normoglycaemia within 4 h of glucagon administration. However, recurrent hypoglycaemia was common (up to 55%). Glucagon increased blood glucose concentration at 1-2 h by 2.3 mmol/L (95% CI 2.1, 2.5) (low certainty evidence, 6 studies, N = 323). There were few data for other important clinical outcomes.

CONCLUSION

There is a paucity of evidence about the efficacy and safety of glucagon for treatment of neonatal hypoglycaemia. Low certainty evidence suggests that glucagon may increase blood glucose by ∼2.3 mmol/L but recurrent hypoglycaemia appears common. High-quality, randomized controlled trials are required to determine the role of glucagon in managing neonatal hypoglycaemia.