The impact of maternal diabetes on the future health and neurodevelopment of the offspring: a review of the evidence

Preventing Childhood Neurodisability

Globally 8.4% of children under 5 years old have a neurodisability. The important factors contributing to this are infection and inflammation, nutrition and quality of care especially during pregnancy and in the first 2 years of life. In an attempt to reduce neurodisability arising from these factors, WHO launched the 1,000 days initiative in 2014. Recent data from the National Health and Morbidity, and Malaysian National Neonatal Registry is a cause for concern. The rate of low weight babies has shown a significant increase during this period. The percentage of pregnant mothers with diabetes has doubled over the last 6 years. In addition, 20% of children under 5 years old are stunted and 46% have anaemia. All of these impact on neurological development, potentially increasing the incidence of developmental disorders and motor deficits.

Exercise and insulin glargine administration in mothers with diabetes during pregnancy ameliorate function of testis in offspring: Consequences on apelin-13 and its receptor

AIMS

Despite the evidence exhibited that diabetes during gestation (DDG) is linked with reproductive dysfunction in offspring, the underlying cellular mechanisms involved are not precisely defined. This study was designed to assess the impact of voluntary exercise and insulin glargine on DDG-induced metabolic and reproductive disorders in male offspring.

MAIN METHODS

Fifty female Wistar rats (three weeks old) received a control diet (n = 10) or high-fat-high-sucrose diet (to induce DDG; n = 40) for six weeks before breeding. From the 7th day of pregnancy onwards, blood glucose over 140 mg/dL was characterized as DDG. Then, the DDG animals were randomly divided into four subgroups with/without voluntary exercise and/or insulin glargine. To evaluate insulin resistance, a glucose tolerance test was performed on the 15th day of pregnancy. After three weeks, male offspring were weaned, and fed a control diet until 12 weeks old. At the end of the experiment, the lipid profile, sex hormones, and apelin-13 in the serum, mRNA expression of apelin receptors (APJ) in the testis and sperm analysis were assessed.

KEY FINDINGS

Our results indicated that voluntary exercise and/or insulin glargine administration in mothers with DDG ameliorated lipid profile, and sex hormones alterations, reduced the serum level of apelin-13, as well as increased APJ expression in testis, and quality of sperm in offspring.

SIGNIFICANCE

Combined administration of voluntary exercise and insulin glargine during pregnancy by regulating of apelinergic system and inhibiting the metabolic and reproductive complications induced by DDG, can be considered as a suitable therapeutic strategy for improving sub-or in-fertility in the male offspring.

Fetal brain development in pregnancies complicated by gestational diabetes mellitus

OBJECTIVES

Gestational diabetes mellitus (GDM) carries an increased risk of neurocognitive impairment in offsprings. However, the contribution of maternal hyperglycemia in affecting fetal brain development is not fully elucidated yet. The aim of this study was to evaluate fetal brain and sulci development in pregnancies complicated by GDM.

METHODS

Prospective observational study including 100 singleton pregnancies complicated by GDM and 100 matched controls. All fetuses underwent neurosonography at 29-34 weeks of gestation, including the assessment of the length of the corpus callosum (CC), cerebellar vermis (CV), Sylvian (SF), parieto-occipital (POF) and calcarine fissures (CF). Sub-group analysis according to the specific treatment regimen adopted (n 67 diet vs. 33 insulin therapy) was also performed.

RESULTS

Fetuses from mothers with GDM under insulin therapy had a smaller CC (35.54 mm) compared to both controls (40 mm; p<0.001) and women with GDM under diet (39.26 mm; p=0.022) while there was no difference in the HC between the groups. Likewise, when corrected for HC, CV depth was smaller in fetuses with GDM both under insulin therapy (7.03 mm) and diet (7.05 mm,) compared to controls (7.36 mm; p=0.013). Finally, when assessing the sulci development of the brain SF (p≤0.0001), POF (p≤0.0001) and CF (p≤0.0001) were significantly smaller in fetuses with maternal GDM. Post-hoc analysis showed that fetuses of GDM mothers requiring insulin therapy had significantly lower values of SF (p=0.032), POF (p=0.016) and CF (p=0.001).

CONCLUSIONS

Pregnancies complicated by GDM showed a peculiar pattern of fetal brain growth and cortical development and these changes, which are more evident in those requiring insulin supplementation.

Does Intrauterine Exposure to Diabetes Impact Mental and Motor Skills? A Meta-Analysis of the Bayley Scales of Infant Development

BACKGROUND

Attempts to conduct meta-analyses of the association between child development and diabetes have been limited by the wide range of tools and definitions of developmental outcomes used in the literature. We aim to meta-analyze a widely used measure of child development, the Bayley Scales of Infant Development, with respect to exposure to diabetes and developmental scores.

METHODS

PsycINFO, MEDLINE/PubMed, EMBASE, Emcare, and Google Scholar databases were searched. Two independent reviewers screened, extracted, and quality-appraised the studies using JBI SUMARI software. Forest plots were created with the standardized mean difference using the random-effects model, and heterogeneity was assessed using I2.

RESULTS

Seven studies were identified. The pooled results on psychomotor and mental development index mean scores were lower for infants born to mothers with diabetes than for the control group (Cohen's d = -4.49, df = 7, I2 = 0%, p = 0.001 and Cohen's d = -3.4, df = 9, I2 = 27%, p = 0.001, respectively). Effects were larger in infants born to mothers with type 1 and 2 diabetes and at age 12 months.

CONCLUSIONS

Maternal diabetes should be considered as a risk factor for children's development, mainly when born to mothers with pre-existing diabetes.

Insulitis in human type 1 diabetes: lessons from an enigmatic lesion

Type 1 diabetes is caused by a deficiency of insulin secretion which has been considered traditionally as the outcome of a precipitous decline in the viability of β-cells in the islets of Langerhans, brought about by autoimmune-mediated attack. Consistent with this, various classes of lymphocyte, as well as cells of the innate immune system have been found in association with islets during disease progression. However, analysis of human pancreas from subjects with type 1 diabetes has revealed that insulitis is often less intense than in equivalent animal models of the disease and can affect many fewer islets than expected, at disease onset. This is especially true in subjects developing type 1 diabetes in, or beyond, their teenage years. Such studies imply that both the phenotype and the number of immune cells present within insulitic lesions can vary among individuals in an age-dependent manner. Additionally, the influent lymphocytes are often mainly arrayed peripherally around islets rather than gaining direct access to the endocrine cell core. Thus, insulitis remains an enigmatic phenomenon in human pancreas and this review seeks to explore the current understanding of its likely role in the progression of type 1 diabetes.

The impact of gestational diabetes on the development of fetal frontal lobe: A case-control study from a tertiary center

PURPOSE

To determine the effects of gestational diabetes mellitus (GDM) on fetal frontal lobe development.

METHODS

This study was conducted prospectively between May 2023 and August 2023 in Ankara City Hospital perinatology clinic. Maternal age, maternal body mass index (BMI), gestational week (GW), biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), estimated fetal weight (EFW), frontal antero-posterior diameter (FAPD), occipito-frontal diameter (OFD), FAPD/OFD ratio, and FAPD/HC ratio, were compared between GDM (n = 40) and low risk controls (n = 56).

RESULTS

The mean maternal age was found higher in the GDM group compared to control group (p = 0.002). Maternal BMI was significantly higher in the GDM group than the control group (p = 0.01). Abdominal circumference (AC) was significantly higher in the GDM group compared to control group (p = 0.04). EFW was significantly higher in the GDM group compared to control group (p = 0.04). FAPD/OFD ratio was found to be higher in the GDM group than in the control group (p = 0.001). Among GDM patients, no statistically significant difference was found in the ultrasound measurements between the groups receiving insulin treatment and those without treatment. According to the correlation analysis results a moderate, positive, and statistically significant correlation was present between FAPD/OFD and GDM. In perinatal outcomes, the rate of neonatal intensive care unit admission was significantly higher in the GDM group.

DISCUSSION

Fetal frontal lobe development seems to be affected by GDM.

Exogenous IL-17A Alleviates Social Behavior Deficits and Increases Neurogenesis in a Murine Model of Autism Spectrum Disorders

Among the proposed mechanisms for autism spectrum disorders (ASD) is immune dysregulation. The proinflammatory cytokine Interleukine-17A (IL-17A) was shown to play a key role in mediating immune-related neurodevelopmental impairment of social behavior. Nevertheless, post-developmental administration of IL-17A was found to increase social behavior. In the present study, we explored the effect of post-developmental administration of IL-17A on ASD-like behaviors induced by developmental exposure to valproic acid (VPA) at postnatal day 4. At the age of seven weeks, VPA-exposed mice were intravenously injected twice with recombinant murine IL-17A (8 μg), and a week later, they were assessed for ASD-like behavior. IL-17A administration increased social behavior and alleviated the ASD-like phenotype. Behavioral changes were associated with increased serum levels of IL-17 and Th17-related cytokines. Exogenous IL-17A also increased neuritogenesis in the dendritic tree of doublecortin-expressing newly formed neurons in the dentate gyrus. Interestingly, the effect of IL-17A on neuritogenesis was more noticeable in females than in males, suggesting a sex-dependent effect of IL-17A. In conclusion, our study suggests a complex role for IL-17A in ASD. While contributing to its pathology at the developmental stage, IL-17 may also promote the alleviation of behavioral deficits post-developmentally by promoting neuritogenesis and synaptogenesis in the dentate gyrus.

Does diabetes mellitus affect the development of fetal brain structures and spaces including corpus callosum, subarachnoid space, insula, and parieto-occipital fissure?

PURPOSE

We investigated the impact of pregestational and gestational diabetes mellitus (PGDM and GDM) on the development of fetal intracranial structures and spaces.

METHODS

This prospective cross-sectional study involved singleton pregnancies between 20 and 32 weeks of gestation. The study comprised a control group (n = 65) of healthy pregnant women without diabetes mellitus (DM); a PGDM group (n = 43) of pregnant women having type 2 DM in a controlled diabetic state; and a GDM group (n = 26) of pregnant women with GDM diagnosed with 2-h 75-g oral glucose tolerance test and received intervention to reduce the diabetic impact on fetus. During neurosonographic evaluation, the simultaneous measurements of corpus callosum (CC) width and depth in the midsagittal image; and lateral craniocortical and posterior craniocortical widths of the subarachnoid space and insular and parieto-occipital fissure depths in the axial image were performed. Before statistical analysis, these values were carefully adjusted for the occipitofrontal diameter.

RESULTS

The DM groups displayed substantially higher frequencies of family history of DM and obstetric history of GDM compared to the control group (p < 0.05). Regarding the neurosonographic parameters, the CC length and insular and parieto-occipital fissure depths were significantly increased in the GDM group but not in the PGDM group (p < 0.05). No significant difference was found among the study groups regarding other neurosonographic parameters (p > 0.05).

CONCLUSION

The results of neurosonographical evaluation of fetal brain structures and spaces reveal that diabetic impact may not be seen in the presence of PGDM, especially in pregnant women receiving prenatal interventions to reduce or avoid diabetic adverse effects on fetal brain development. The effect of GDM on neurosonographically assessed fetal brain development should be evaluated in further studies with subjects matched for gestational weeks and antenatal care conditions.

Optimally Controlled Diabetes and Its Influence on Neonatal Outcomes at a Level II Center: A Study on Infants Born to Diabetic Mothers

Background and Objectives: We investigated the effect of optimal maternal glycemic control on neonatal outcomes among infants born to mothers with diabetes. Materials and Methods: In this prospective study, we assessed 88 eligible mothers admitted to the obstetrics department for pregnancy evaluation. Our analysis included 46 infants born to diabetic mothers (IDMs) and 138 infants born to unaffected mothers, all admitted to the Level II Neonatal Intensive Care Unit (NICU). Results: Mothers affected by diabetes were generally older and exhibited a higher body mass index (BMI) and a greater number of gestations, although parity did not differ significantly. Cesarean section emerged as the most frequently chosen mode of delivery. A significantly higher proportion of infants in the affected group presented with respiratory disease (3% vs. 19.5%), which required NICU admission (4.3% vs. 23.9%), phototherapy (18.1% vs. 43.5%), and had congenital heart defects or myocardial hypertrophy (15.2% and 26% vs. 3% and 4.3%) compared to matched controls (p < 0.05). Conclusions: This study underscores the persistence of adverse neonatal outcomes in IDMs, even when maternal glycemic control is optimized. It calls for further investigation into potential interventions and strategies aimed at enhancing neonatal outcomes in this population.

Metformin in Gestational Diabetes Mellitus: To Use or Not to Use, That Is the Question

In recent years, there has been a dramatic increase in the number of pregnancies complicated by gestational diabetes mellitus (GDM). GDM occurs when maternal insulin resistance develops and/or progresses during gestation, and it is not compensated by a rise in maternal insulin secretion. If not properly managed, this condition can cause serious short-term and long-term problems for both mother and child. Lifestyle changes are the first line of treatment for GDM, but if ineffective, insulin injections are the recommended pharmacological treatment choice. Some guidance authorities and scientific societies have proposed the use of metformin as an alternative pharmacological option for treating GDM, but there is not yet a unanimous consensus on this. Although the use of metformin appears to be safe for the mother, concerns remain about its long-term metabolic effects on the child that is exposed in utero to the drug, given that metformin, contrary to insulin, crosses the placenta. This review article describes the existing lines of evidence about the use of metformin in pregnancies complicated by GDM, in order to clarify its potential benefits and limits, and to help clinicians make decisions about who could benefit most from this drug treatment.