Effects of gestational and pregestational diabetes mellitus on the foetal heart: a cross-sectional study

Abstract

We examined the foetal cardiac structural and functional characteristics in diabetic pregnancies versus non-diabetic, healthy pregnancies. Between August 2015 and April 2016, 32 pregnant women with pregestational diabetes, 36 pregnant women with gestational diabetes, and 42 healthy pregnant women were scheduled to have foetal echocardiograms to assess cardiac structure and function. In the diabetic groups, the foetal interventricular septum (IVS) thickness was significantly greater than in non-diabetics (p < .05) but none had an IVS >2 SD from normal. The peak velocity of tricuspid E, and the E/A ratio were significantly lower in the diabetic groups (p < .05). Tricuspid valve E values and the E/A ratio were lower in the diabetic group than in the control group (p < .05) but there was no significant difference between the pre-GDM and GDM groups (p > .05). Interventricular septal hypertrophy is the most common structural abnormality in diabetic pregnancies. These changes do not pose a risk to the foetal unless they cause functional impairment. Thus, we believe that it is important for diabetic pregnant women to be monitored for foetal cardiac diastolic dysfunction. Impact statement What is already known on this subject? Pregestational insulin-dependent diabetes mellitus is a relatively common condition in pregnancy, affecting up to 0.5% of the pregnant population. Foetuses of diabetic mothers are at an increased risk of perinatal morbidity and death. Gestational diabetes mellitus is under-recognised and affects up to 4% of pregnancies. Although diabetes mellitus is known to increase the risk of cardiovascular defects and structural changes (myocardial hypertrophy and diastolic dysfunction) due to foetal hyperglycaemia and hyperinsulinism, similar data in women with gestational diabetes is scarce. Moreover, the effect of maternal hyperglycaemia on foetal cardiac structure and function is unclear because of discordant results from previous studies. What do the results of this study add? In this study, we have used foetal echocardiography, two-dimensional US, pulsed wave Doppler and TDI to characterise the foetal cardiac structure and function in normal pregnancies as well as in the pregnancies complicated by GDM, and pregestational DM. Interventricular septum thickness is increased in women with pregestational diabetes mellitus and impaired diastolic function. The dominant right ventricle of the foetal circulation was affected earlier than the left ventricle. What are the implications of these findings for clinical practice and/or further research? Large population-based studies are required to establish the absolute risk of congenital heart defects in patients with pregestational diabetes and pregestational diabetes in the utility of routine screening.

Effect of gestational diabetes and insulin resistance on offspring’s myocardial relaxation kinetics at three years of age

“…The results of these studies showed differences in PWD velocities or differences in myocardial deformation that could be compatible with impaired myocardial relaxation in fetuses exposed to a hyperglycemic uterine environment. [ 8 , 9 ] In both studies, authors observed increased septal thickness in fetuses from diabetic women. However, Miranda et al showed that differences in myocardial deformation were independent of septal hypertrophy.…”

“…Although cardiac hypertrophy in relation to hyperglycemia is usually transient and resolves in the first months of life, some studies have shown that signs of abnormal myocardial relaxation in fetuses and newborns were not always related to hypertrophy and can be present in patients without myocardial hypertrophy. [ 6 , 8 , 9 ] The spontaneous regression of cardiac hypertrophy has led clinicians not to follow these patients after the first few months of life. However, there is a paucity of data on diastolic function in the first years of life in children from mothers with insulin resistance and GDM during pregnancy.…”

Fetal echocardiography at term in diabetic pregnancies helps predict the adverse neonatal outcome - Results of a prospective observational study from South India

“…Thus, fetal IVS hypertrophy among diabetic pregnancies - is seen uniformly in the published literature. 6 , 7 …”

Epigenetic Down-Regulation of Sirt 1 via DNA Methylation and Oxidative Stress Signaling Contributes to the Gestational Diabetes Mellitus-Induced Fetal Programming of Heart Ischemia-Sensitive Phenotype in Late Life

“…The prevalence of gestational diabetes mellitus (GDM) has been increasing all over the world and growing evidence suggests that GDM has adverse effects not only on mothers but also on their offspring 1. Previous studies have reported that GDM could cause cardiac development defects and increase morbidity of congenital heart defects 2. Furthermore, maternal GDM has been shown to act as an independent risk factor for development of cardiovascular disease in offspring late in life 3.…”