Pregestational Diabetes Mellitus and Congenital Heart Defects

Risk factors for isolated congenital heart defects in infants from Western Mexico

Congenital heart defects (CHDs) are caused by a complex interaction between numerous genetic and environmental risk factors, some of which may differ between different populations. A case-control study was conducted among 1232 newborns, including 308 patients with isolated CHDs (cases) and 924 infants without birth defects (controls), born all during the period 2009-2023 at the Hospital Civil de Guadalajara "Dr. Juan I. Menchaca" (Guadalajara, Mexico). Potential parental risk factors for CHDs were compared using multivariate logistic regression analysis to evaluate the deviance explained by different variables of interest. Consanguinity [adjusted odds ratio (aOR) = 3.3; 95% confidence interval (CI) 1.3-8.5], relatives with CHD (aOR = 8.5; 95% CI 5.3-13.8), maternal first-trimester exposure to diabetes (aOR = 3.5; 95% CI 2.4-5.1), hypertension (aOR = 2.6; 95% CI 1.5-4.4), alcohol consumption (aOR = 1.5; 95% CI 1.0-2.1), and illicit drug use (aOR = 2.4; 95% CI 1.2-5.3), as well as for the paternal history of alcohol consumption (aOR = 1.4; 95% CI 1.0-1.8) and illicit drug use (aOR = 2.7; 95% CI 1.7-4.1), were associated with CHDs. Contrarily, aOR for maternal age ≤19 years (aOR = 0.6; 95% CI 0.4-0.8) and maternal first-trimester coffee consumption (aOR = 0.7; 95% CI 0.5-0.9) have protective odds. Our results suggest that genetic factors, maternal diseases, environmental exposures, and reproductive factors can increase the occurrence of isolated CHDs in our sample, and they are discussed as clues in its pathogenesis.

Impact of genetic factors on antioxidant rescue of maternal diabetes-associated congenital heart disease

Congenital heart disease (CHD) affects approximately 1% of live births. Although genetic and environmental etiologic contributors have been identified, the majority of CHD lacks a definitive cause, suggesting the role of gene-environment interactions (GxEs) in disease pathogenesis. Maternal diabetes mellitus (matDM) is among the most prevalent environmental risk factors for CHD. However, there is a substantial knowledge gap in understanding how matDM acts upon susceptible genetic backgrounds to increase disease expressivity. Previously, we reported a GxE between Notch1 haploinsufficiency and matDM leading to increased CHD penetrance. Here, we demonstrate a cell lineage-specific effect of Notch1 haploinsufficiency in matDM-exposed embryos, implicating endothelial/endocardial tissues in the developing heart. We report impaired atrioventricular cushion morphogenesis in matDM-exposed Notch1+/- animals and show a synergistic effect of NOTCH1 haploinsufficiency and oxidative stress in dysregulation of gene regulatory networks critical for endocardial cushion morphogenesis in vitro. Mitigation of matDM-associated oxidative stress via superoxide dismutase 1 overexpression did not rescue CHD in Notch1-haploinsufficient mice compared to wild-type littermates. Our results show the combinatorial interaction of matDM-associated oxidative stress and a genetic predisposition, Notch1 haploinsufficiency, on cardiac development, supporting a GxE model for CHD etiology and suggesting that antioxidant strategies alone may be ineffective in genetically susceptible individuals.

Risk of major congenital heart disease in pregestational maternal diabetes is modified by hemoglobin A1c

OBJECTIVES

The association between pregestational diabetes mellitus (PDM) and risk of congenital heart disease (CHD) is well recognized; however, the importance of glycemic control and other coexisting risk factors during pregnancy is less clear. We sought to determine the relative risk (RR) of major CHD (mCHD) among offspring from pregnancies complicated by PDM and the effect of first-trimester glycemic control on mCHD risk.

METHODS

We determined the incidence of mCHD (requiring surgery within 1 year of birth or resulting in pregnancy termination or fetal demise) among registered births in Alberta, Canada. Linkage of diabetes status, maximum hemoglobin A1c (HbA1c) at < 16 weeks' gestation and other covariates was performed using data from the Alberta Perinatal Health Program registry. Risk of mCHD according to HbA1c was estimated as an adjusted RR (aRR), calculated using log-binomial modeling.

RESULTS

Of 1412 cases of mCHD in 594 773 (2.37/1000) births in the study period, mCHD was present in 48/7497 with PDM (6.4/1000; RR, 2.8 (95% CI, 2.1-3.7); P < 0.0001). In the entire cohort, increased maternal age (aRR, 1.03 (95% CI, 1.02-1.04); P < 0.0001) and multiple gestation (aRR, 1.37 (95% CI, 1.1-1.8); P = 0.02) were also associated with mCHD risk, whereas maternal prepregnancy weight > 91 kg was not. The stratified risk for mCHD associated with HbA1c ≤ 6.1%, > 6.1-8.0% and > 8.0% was 4.2/1000, 6.8/1000 and 17.1/1000 PDM/gestational diabetes mellitus births, respectively; the aRR of mCHD associated with PDM and HbA1c > 8.0% was 8.5 (95% CI, 5.0-14.4) compared to those without diabetes and 5.5 (95% CI, 1.6-19.4) compared to PDM with normal HbA1c (≤ 6.1%).

CONCLUSIONS

PDM is associated with a RR of 2.8 for mCHD, increasing to 8.5 in those with HbA1c > 8%. These data should facilitate refinement of referral indications for high-risk pregnancy screening. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

ER stress and lipid imbalance drive embryonic cardiomyopathy in a human heart organoid model of pregestational diabetes

Congenital heart defects constitute the most common birth defect in humans, affecting approximately 1% of all live births. The incidence of congenital heart defects is exacerbated by maternal conditions, such as diabetes during the first trimester. Our ability to mechanistically understand these disorders is severely limited by the lack of human models and the inaccessibility to human tissue at relevant stages. Here, we used an advanced human heart organoid model that recapitulates complex aspects of heart development during the first trimester to model the effects of pregestational diabetes in the human embryonic heart. We observed that heart organoids in diabetic conditions develop pathophysiological hallmarks like those previously reported in mouse and human studies, including ROS-mediated stress and cardiomyocyte hypertrophy, among others. Single cell RNA-seq revealed cardiac cell type specific-dysfunction affecting epicardial and cardiomyocyte populations, and suggested alterations in endoplasmic reticulum function and very long chain fatty acid lipid metabolism. Confocal imaging and LC-MS lipidomics confirmed our observations and showed that dyslipidemia was mediated by fatty acid desaturase 2 (FADS2) mRNA decay dependent on IRE1-RIDD signaling. We also found that the effects of pregestational diabetes could be reversed to a significant extent using drug interventions targeting either IRE1 or restoring healthy lipid levels within organoids, opening the door to new preventative and therapeutic strategies in humans.

Pregestational Diabetes and Congenital Heart Defects

Studies have consistently shown a significant increase in the risk of congenital heart defects in the offspring of diabetic mothers compared with those of nondiabetic pregnancies. Evidence points that all types of pregestational diabetes have the capacity of generating cardiac malformations in a more accentuated manner than in gestational diabetes, and there seems to be an increased risk for all congenital heart defects phenotypes in the presence of maternal diabetes. Currently, the application of some therapies is under study in an attempt to reduce the risks inherent to diabetic pregnancies; however, it has not yet been possible to fully prove their effectiveness. The present review aims to better understand the mechanisms that govern the association between pregestational diabetes and congenital heart defects and how maternal diabetes interferes with fetal cardiac development, as there is still a long way to go in the investigation of this complex process.

Modeling the Effects of Maternal Diabetes on the Developing Human Heart Using Pluripotent Stem Cell-Derived Heart Organoids

Congenital heart defects (CHD) constitute the most common type of birth defect in humans. Maternal diabetes during the first trimester of pregnancy (pregestational diabetes, or PGD) is one of the most prominent factors contributing to CHD, and is present in a significant population of female patients with diabetes in reproductive age. PGD is challenging to manage clinically due to the extreme sensitivity of the developing embryo to glucose oscillations, and constitutes a critical health problem for the mother and the fetus. The prevalence of PGD-induced CHD is increasing due to the ongoing diabetes epidemic. While studies using animal models and cells in culture have demonstrated that PGD alters critical cellular and developmental processes, the mechanisms remain obscure, and it is unclear to what extent these models recapitulate PGD-induced CHD in humans. Clinical practice precludes direct studies in developing human embryos, further highlighting the need for physiologically relevant models. To bypass many of these technical and ethical limitations, we describe here a human pluripotent stem cell (hPSC)-based method to generate developmentally relevant self-organizing human heart organoids. By using glucose and insulin to mimic the diabetic environment that the embryo faces in PGD, this system allows modeling critical features of PGD in a human system with relevant physiology, structure, and cell types. The protocol starts with the generation of hPSC-derived embryoid bodies in a 96-well plate, followed by a small molecule-based three-step Wnt activation/inhibition/activation strategy. Organoids are then differentiated under healthy (normal insulin and glucose) and diabetic conditions (high insulin and glucose) over time, allowing for the study of the effects of pregestational diabetes on the developing human heart. We also provide an immunofluorescence protocol for comparing, characterizing, and analyzing the differences between the healthy and diabetic organoids, and comment on additional steps for preparing the organoids for analysis by other techniques after differentiation. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Generation of hPSC-derived embryoid bodies Basic Protocol 2: Differentiation of EBs into heart organoids under healthy and diabetes-like conditions Basic Protocol 3: Immunofluorescence and organoid preparation for other assays.

Risk factors associated with congenital anomalies among newborns in southwestern Ethiopia: A case-control study

INTRODUCTION

Human embryo is well protected in the uterus by the embryonic membrane, although teratogens may cause developmental disruptions after maternal exposure to them during early pregnancy. Most of the risk factors contributing to the development of congenital anomalies are uncertain; however, genetic factors, environmental factors and multifactorial inheritance are found to be risk factors. Regardless of their clinical importance, there are little/no studies conducted directly related to predisposing risk factors in southwestern Ethiopia.

OBJECTIVE

The study aimed to determine the associated risk factors with congenital anomalies among newborns in southwestern Ethiopia.

METHODS

Case-control study was conducted on newborns and their mothers in six purposively selected hospitals in southwestern Ethiopia from May 2016 to May 2018. Data was collected after evaluation of the neonates for the presence of congenital anomalies using the standard pretested checklist. The data was analyzed using SPSS version 25.0. P <0.01 was set as statistically significant.

RESULTS

Risk factors such as unidentified medicinal usage in the first three months of pregnancy (AOR = 3.435; 99% CI: 2.012-5.863), exposure to pesticide (AOR = 3.926; 99% CI: 1.266-12.176), passive smoking (AOR = 4.104; 99% CI: 1.892-8.901), surface water as sources of drinking (AOR = 2.073; 99% CI: 1.221-3.519), folic acid supplementation during the early pregnancy (AOR = 0.428; 99% CI: 0.247-0.740) were significantly associated with the congenital anomalies.

CONCLUSIONS

In this study, risk factors such as passive smoking, exposure to pesticides, chemicals and use of surface water as a source of drinking during early pregnancy had a significant association with congenital anomalies. There is a need to continuously provide health information for the community on how to prevent and control predisposing risk factors.

Incidence and mortality trend of congenital heart disease at the global, regional, and national level, 1990-2017

Congenital heart disease (CHD) is the most commonly diagnosed congenital disorder in newborns. The incidence and mortality of CHD vary worldwide. A detailed understanding of the global, regional, and national distribution of CHD is critical for CHD prevention.We collected the incidence and mortality data of CHD from the Global Burden of Disease study 2017 database. Average annual percentage change was applied to quantify the temporal trends of CHD incidence and mortality at the global, regional, and national level, 1990-2017. A sociodemographic index (SDI) was created for each location based on income per capita, educational attainment, and fertility.The incidence of CHD was relatively high in developing countries located in Africa and Asia, while low in most developed countries. Between 1990 and 2017, the CHD incidence rate remained stable at the global level, whereas increased in certain developed countries, such as Germany and France. The age-standardized mortality rate of CHD declined substantially over the last 3 decades, regardless of sex, age, and SDI region. The decline was more prominent in developed countries. We also detected a significant positive correlation between CHD incidence and CHD mortality in both 1990 and 2017, by SDI.The incidence of CHD remained stable over the last 3 decades, suggesting little improvement in CHD prevention strategies and highlighting the importance of etiological studies. The mortality of CHD decreased worldwide, albeit the greatly geographical heterogeneity. Developing countries located in Africa and Asia deserve more attention and priority in the global CHD prevention program.

Prenatal, Obstetric and Perinatal Aspects in Pregnancy Associated with Pregestational Diabetes

ABSTRACT: We report the case of a 37-year old primigesta, primipara (IGIP) patient with a singleton, naturally obtained pregnancy, diagnosed with type I diabetes mellitus from the age of three, carrier of an insulin pump for 11 years. The patient was diagnosed in adolescence with with a tumor of the ischio-rectal fossa with multiple attempts of excision which failed due to the particular situation of the tumor. Ultrasound examination diagnosed in the first trimester of pregnancy a voluminous right ovarian cystic tumor. The patient presented pregnancy-induced hypertension starting with 28 gestational weeks. Maternal-fetal and obstetric management assumed sequential ultrasound examination, ovarian tumor and maternal blood pressure drug control, and also the surgical management of the ischio-rectal tumor. Cesarean section was performed at 38 gestational weeks, outcoming with a live fetus, normal weight, good neonatal progression and favorable postoperative progression of the mother. In this case report, we emphasize the fact that in pregestational diabetes mellitus and pregnancy-induced hypertension, constant glycemic control, performed by the insulin pump, prior and during gestation, and the maternal blood pressure control are essential for maternal-fetal outcome.