Maternal diabetic control and hypertrophic cardiomyopathy in infants of diabetic mothers

Maternal Diabetes and Intrapartum Fetal Electrocardiogram

OBJECTIVE

 Fetal electrocardiogram (ECG) ST changes are associated with fetal cardiac hypoxia. Our objective was to evaluate ST changes by maternal diabetic status and stage of labor.

METHODS

 This was a secondary analysis of a multicentered randomized-controlled trial in which laboring patients with singleton gestations underwent fetal ECG scalp electrode placement and were randomly assigned to masked or unmasked ST-segment readings. Our primary outcome was the frequency of fetal ECG tracings with ST changes by the stage of labor. ECG tracings were categorized into mutually exclusive groups (ST depression, ST elevation without ST depression, or no ST changes). We compared participants with DM, gestational diabetes mellitus (GDM), and no DM.

RESULTS

 Of the 5,436 eligible individuals in the first stage of labor (95 with pregestational DM and 370 with GDM), 4,427 progressed to the second stage. ST depression occurred more frequently in the first stage of labor in participants with pregestational DM (15%, adjusted odds ratio [aOR] 2.20, 95% confidence interval [CI] 1.14-4.24) and with GDM (9.5%, aOR 1.51, 95% CI 1.02-2.25) as compared with participants without DM (5.7%). The frequency of ST elevation was similar in participants with pregestational DM (33%, aOR 0.79, 95% CI 0.48-1.30) and GDM (33.2%, aOR 0.91, 95% CI 0.71-1.17) as compared with those without DM (34.2%). In the second stage, ST depression did not occur in participants with pregestational DM (0%) and occurred more frequently in participants with GDM (3.5%, aOR 2.01, 95% CI 1.02-3.98) as compared with those without DM (2.0%). ST elevation occurred more frequently in participants with pregestational DM (30%, aOR 1.81, 95% CI 1.02-3.22) but not with GDM (19.0%, aOR 1.06, 95% CI 0.77-1.47) as compared with those without DM (17.8%).

CONCLUSION

 ST changes in fetal ECG occur more frequently in fetuses of diabetic mothers during labor.

CLINICALTRIALS

gov number, NCT01131260.

PRECIS

 ST changes in fetal ECG, a marker of fetal cardiac hypoxia, occur more frequently in fetuses of diabetic parturients.

KEY POINTS

· Fetal hypertrophic cardiomyopathy (HCM) and cardiac dysfunction occur frequently among fetuses of diabetic patients.. · Fetal ECG changes such as ST elevation and depression reflect cardiac hypoxia.. · Fetuses of diabetic patients demonstrate a higher prevalence of fetal ECG tracings with ST changes..

Effect of glycemic control on fetal hearts of pregestational diabetic women by tissue doppler and M-mode imaging

OBJECTIVE

To determine whether changes in fetal heart function according to glycemic control in pregnant women with Type 1 and Type 2 diabetes using spectral tissue Doppler imaging (TDI) and M-mode imaging.

METHODS

This study included 68 pregestational diabetic women (DM) at 30-32 gestational weeks. All participants were divided into two groups: type 1(n = 17) and type 2(n = 51), and then these groups were divided into the subgroups as well-controlled and poorly controlled, according to fasting glucose (FG) and 1-h postprandial glucose (PPG) values. Cardiac parameters were compared for well- and poorly-controlled groups with TDI and M-mode imaging. The correlation of cardiac parameters with FG, PPG, and HbA1c values was evaluated. Their roles in predicting neonatal outcomes were also assessed.

RESULTS

Thickness measurements, early diastolic annular peak velocity (E'), late diastolic annular peak velocity (A'), tissue isovolumetric relaxation time (IRT'), and tissue myocardial performance index (MPI') were increased in both poorly controlled groups. Tissue ejection time (ET') was significantly reduced in the poorly controlled groups, while tissue isovolumetric contraction time (ICT') was not significantly changed in any group. Tricuspid, mitral, and septal annular plane excursions (TAPSE, MAPSE, and SAPSE, respectively) were significantly decreased in all poorly controlled subgroups. E', E'/A', MPI', IRT', ET', and M-mode imaging parameters significantly correlated with FG notably.

CONCLUSION

Maternal hyperglycemia leads to subtle changes in systolic and diastolic functions both in the interventricular septum and ventricles, so it is essential to ensure glycemic control in both Type 1 and Type 2 DM.

Recent Experimental Studies of Maternal Obesity, Diabetes during Pregnancy and the Developmental Origins of Cardiovascular Disease

Globally, cardiovascular disease remains the leading cause of death. Most concerning is the rise in cardiovascular risk factors including obesity, diabetes and hypertension among youth, which increases the likelihood of the development of earlier and more severe cardiovascular disease. While lifestyle factors are involved in these trends, an increasing body of evidence implicates environmental exposures in early life on health outcomes in adulthood. Maternal obesity and diabetes during pregnancy, which have increased dramatically in recent years, also have profound effects on fetal growth and development. Mounting evidence is emerging that maternal obesity and diabetes during pregnancy have lifelong effects on cardiovascular risk factors and heart disease development. However, the mechanisms responsible for these observations are unknown. In this review, we summarize the findings of recent experimental studies, showing that maternal obesity and diabetes during pregnancy affect energy metabolism and heart disease development in the offspring, with a focus on the mechanisms involved. We also evaluate early proof-of-concept studies for interventions that could mitigate maternal obesity and gestational diabetes-induced cardiovascular disease risk in the offspring.

Nutritional and developmental programming effects of insulin

The discovery of insulin in 1921 was a major breakthrough in medicine and for therapy in patients with diabetes. The dramatic rise in the prevalence of overweight and obesity has been tightly linked to an increased prevalence of gestational diabetes mellitus (GDM), which poses major health concerns. Babies born to GDM mothers are more likely to develop obesity, type 2 diabetes and cardiovascular disease later in life. Evidence accumulated during the past two decades has revealed that high levels insulin, such as those observed during GDM, can have a widespread effect on the development and function of a variety of organs. This review summarises our current knowledge on the role of insulin in the placenta, cardiovascular system and brain during critical periods of development, as well as how it can contribute to lifelong metabolic regulation. We also discuss possible intervention strategies to ameliorate and hopefully reverse the developmental defects associated with obesity and GDM.

Persistent Aortic Stiffness and Left Ventricular Hypertrophy in Children of Diabetic Mothers

Background

Fetuses of diabetic mothers develop left ventricular (LV) hypertrophy and are at increased long-term risk of cardiovascular disease. In our previous longitudinal study from midgestation to late infancy we showed persistence of LV hypertrophy and increased aortic stiffness compared with infants of healthy mothers, the latter of which correlated with third trimester maternal hemoglobin A1c. In the present study, we reexamined the same cohort in early childhood to determine if these cardiovascular abnormalities persisted.

Methods

Height, weight, and right arm blood pressure were recorded. A full functional and structural echocardiogram was performed with offline analysis of LV posterior wall and interventricular septal diastolic thickness (IVSd), systolic and diastolic function, and aortic pulse wave velocity. Vascular reactivity was assessed using digital thermal monitoring. Participants also completed a physical activity questionnaire.

Results

Twenty-five children of diabetic mothers (CDMs) and 20 children from healthy pregnancies (mean age, 5.6 ± 1.7 and 5.3 ± 1.3 years, respectively; P = not significant) were assessed. Compared with controls, IVSd z score was increased in CDMs (1.2 ± 0.6 vs 0.5 ± 0.3, respectively; P = 0.006), with one-fifth having a z score of more than +2.0. Aortic pulse wave velocity was increased in CDMs (3.2 ± 0.6 m/s vs 2.2 ± 0.4 m/s; P = 0.001), and correlated with IVSd z score (R² = 0.81; P = 0.001) and third trimester maternal A1c (R² = 0.65; P < 0.0001). Body surface area, height, weight, blood pressure, vascular reactivity, and physical activity scores did not differ between groups. Our longitudinal analysis showed that individuals with greater IVSd, and aortic stiffness in utero, early and late infancy also tended to have greater measures in early childhood (P < 0.001 and P < 0.0001, respectively).

Conclusions

CDMs show persistently increased interventricular septal thickness and aortic stiffness in early childhood.

Neonatal cardiac hypertrophy: the role of hyperinsulinism-a review of literature

Hypertrophic cardiomyopathy (HCM) in neonates is a rare and heterogeneous disorder which is characterized by hypertrophy of heart with histological and functional disruption of the myocardial structure/composition. The prognosis of HCM depends on the underlying diagnosis. In this review, we emphasize the importance to consider hyperinsulinism in the differential diagnosis of HCM, as hyperinsulinism is widely associated with cardiac hypertrophy (CH) which cannot be distinguished from HCM on echocardiographic examination. We supply an overview of the incidence and treatment strategies of neonatal CH in a broad spectrum of hyperinsulinemic diseases. Reviewing the literature, we found that CH is reported in 13 to 44% of infants of diabetic mothers, in approximately 40% of infants with congenital hyperinsulinism, in 61% of infants with leprechaunism and in 48 to 61% of the patients with congenital generalized lipodystrophy. The correct diagnosis is of importance since there is a large variation in prognoses and there are various strategies to treat CH in hyperinsulinemic diseases.Conclusion: The relationship between CH and hyperinsulism has implications for clinical practice as it might help to establish the correct diagnosis in neonates with cardiac hypertrophy which has both prognostic and therapeutic consequences. In addition, CH should be recognized as a potential comorbidity which might necessitate treatment in all neonates with known hyperinsulinism.What is Known:• Hyperinsulinism is currently not acknowledged as a cause of hypertrophic cardiomyopathy (HCM) in textbooks and recent Pediatric Cardiomyopathy Registry publications.What is New:• This article presents an overview of the literature of hyperinsulinism in neonates and infants showing that hyperinsulinism is associated with cardiac hypertrophy (CH) in a broad range of hyperinsulinemic diseases.• As CH cannot be distinguished from HCM on echocardiographic examination, we emphasize the importance to consider hyperinsulinism in the differential diagnosis of HCM/CH as establishing the correct diagnosis has both prognostic and therapeutic consequences.

Say NO to ROS: Their Roles in Embryonic Heart Development and Pathogenesis of Congenital Heart Defects in Maternal Diabetes

Congenital heart defects (CHDs) are the most prevalent and serious birth defect, occurring in 1% of all live births. Pregestational maternal diabetes is a known risk factor for the development of CHDs, elevating the risk in the child by more than four-fold. As the prevalence of diabetes rapidly rises among women of childbearing age, there is a need to investigate the mechanisms and potential preventative strategies for these defects. In experimental animal models of pregestational diabetes induced-CHDs, upwards of 50% of offspring display congenital malformations of the heart, including septal, valvular, and outflow tract defects. Specifically, the imbalance of nitric oxide (NO) and reactive oxygen species (ROS) signaling is a major driver of the development of CHDs in offspring of mice with pregestational diabetes. NO from endothelial nitric oxide synthase (eNOS) is crucial to cardiogenesis, regulating various cellular and molecular processes. In fact, deficiency in eNOS results in CHDs and coronary artery malformation. Embryonic hearts from diabetic dams exhibit eNOS uncoupling and oxidative stress. Maternal treatment with sapropterin, a cofactor of eNOS, and antioxidants such as N-acetylcysteine, vitamin E, and glutathione as well as maternal exercise have been shown to improve eNOS function, reduce oxidative stress, and lower the incidence CHDs in the offspring of mice with pregestational diabetes. This review summarizes recent data on pregestational diabetes-induced CHDs, and offers insights into the important roles of NO and ROS in embryonic heart development and pathogenesis of CHDs in maternal diabetes.

Markers of maternal and infant metabolism are associated with ventricular dysfunction in infants of obese women with type 2 diabetes

BackgroundTo test the hypothesis that infants born to obese women with pre-gestational type 2 diabetes mellitus (IBDMs) have ventricular dysfunction at 1 month that is associated with markers of maternal lipid and glucose metabolism.MethodsIn a prospective observational study of IBDMs (OB+DM, n=25), echocardiographic measures of septal, left (LV) and right ventricular (RV) function, and structure were compared at 1 month of age with those in infants born to OB mothers without DM (OB, n=24) and to infants born to non-OB mothers without DM (Lean, n=23). Basal maternal lipid and glucose kinetics and maternal plasma and infant (cord) plasma were collected for hormone and cytokine analyses.ResultsRV, LV, and septal strain measures were lower in the OB+DM infants compared with those in other groups, without evidence of septal hypertrophy. Maternal hepatic insulin sensitivity, maternal plasma free-fatty-acid concentration, and cord plasma insulin and leptin most strongly predicted decreased septal strain in OB+DM infants.ConclusionIBDMs have reduced septal function at 1 month in the absence of septal hypertrophy, which is associated with altered maternal and infant lipid and glucose metabolism. These findings suggest that maternal obesity and DM may have a prolonged impact on the cardiovascular health of their offspring, despite the resolution of cardiac hypertrophy.

Pregestational type 2 diabetes mellitus induces cardiac hypertrophy in the murine embryo through cardiac remodeling and fibrosis

BACKGROUND

Cardiac hypertrophy is highly prevalent in patients with type 2 diabetes mellitus. Experimental evidence has implied that pregnant women with type 2 diabetes mellitus and their children are at an increased risk of cardiovascular diseases. Our previous mouse model study revealed that maternal type 2 diabetes mellitus induces structural heart defects in their offspring.

OBJECTIVE

This study aims to determine whether maternal type 2 diabetes mellitus induces embryonic heart hypertrophy in a murine model of diabetic embryopathy.

STUDY DESIGN

The type 2 diabetes mellitus embryopathy model was established by feeding 4-week-old female C57BL/6J mice with a high-fat diet for 15 weeks. Cardiac hypertrophy in embryos at embryonic day 17.5 was characterized by measuring heart size and thickness of the right and left ventricle walls and the interventricular septum, as well as the expression of β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, desmin, and adrenomedullin. Cardiac remodeling was determined by collagen synthesis and fibronectin synthesis. Fibrosis was evaluated by Masson staining and determining the expression of connective tissue growth factor, osteopontin, and galectin-3 genes. Cell apoptosis also was measured in the developing heart.

RESULTS

The thicknesses of the left ventricle walls and the interventricular septum of embryonic hearts exposed to maternal diabetes were significantly thicker than those in the nondiabetic group. Maternal diabetes significantly increased β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, and desmin expression, but decreased expression of adrenomedullin. Moreover, collagen synthesis was significantly elevated, whereas fibronectin synthesis was suppressed, in embryonic hearts from diabetic dams, suggesting that cardiac remodeling is a contributing factor to cardiac hypertrophy. The cardiac fibrosis marker, galectin-3, was induced by maternal diabetes. Furthermore, maternal type 2 diabetes mellitus activated the proapoptotic c-Jun-N-terminal kinase 1/2 stress signaling and triggered cell apoptosis by increasing the number of terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling-positive cells (10.4 ± 2.2% of the type 2 diabetes mellitus group vs 3.8 ± 0.7% of the nondiabetic group, P < .05).

CONCLUSION

Maternal type 2 diabetes mellitus induces cardiac hypertrophy in embryonic hearts. Adverse cardiac remodeling, including elevated collagen synthesis, suppressed fibronectin synthesis, profibrosis, and apoptosis, is implicated as the etiology of cardiac hypertrophy.

Heart rate variability in neonates of type 1 diabetic pregnancy

BACKGROUND

Cardiomyopathy is a common finding in offspring of pre-gestational type 1 diabetic pregnancy. Echocardiographic and biochemical evidence of fetal cardiac dysfunction have also been reported. Studies suggest that offspring of diabetic mothers (ODM) undergo a fetal programming effect due to the hyperglycaemic intrauterine milieu which increases their risk of cardiovascular morbidity in adult life. Decreased neonatal heart rate variability (HRV) has been described in association with in-utero growth restriction, prematurity, sudden infant death syndrome and congenital heart disease. The effect of in-utero exposure to hyperglycaemia in diabetic pregnancy on neonatal HRV is unknown.

AIMS

Our aim was to determine if neonatal HRV differs between normal and diabetic pregnancy.

STUDY DESIGN AND SUBJECTS

This was a prospective observational study of 38 patients with pregestational type 1 diabetes and 26 controls. HRV assessment was performed using Powerlab (ADI Instruments Ltd).

OUTCOME MEASURES

Heart rate variability assessment and cord blood sampling for pH and glucose were performed for all neonates. Maternal glycaemic control was assessed via measurement of glycosylated haemoglobin in each trimester in the diabetic cohort.

RESULTS

Neonates of diabetic mothers had evidence of altered heart rate variability, with increased low frequency to high frequency ratio (LF: HF), suggestive of a shift towards sympathetic predominance (p<0.05). This altered HRV was significantly related to fetal acidaemia, cord blood glucose values and maternal glycaemic control during pregnancy (p<0.05).

CONCLUSION

Neonates of pregestational diabetic pregnancy have altered HRV which is related to maternal hyperglycaemia, fetal acidaemia and fetal glycaemia. Exposure of the developing heart to fluctuations in maternal glycaemia with subsequent alterations in HRV may explain why infants of diabetic mothers are at greater risk of cardiovascular disease in later life.

Speckle tracking and myocardial tissue imaging in infant of diabetic mother with gestational and pregestational diabetes

The aim of this study was to evaluate the myocardial changes in infants of diabetic mother either with gestational or pregestational diabetes and its relation to maternal diabetic control. The study included 45 infants of diabetic mother (IDMs) and 45 healthy newborn as a control group. IDMs were then categorized into 2 subgroups: twenty infants of mother with pregestational diabetes and twenty-five infants of mothers with gestational diabetes. The studied groups underwent measurement of the maternal and neonatal glycated Hb % (HbA1c), conventional echocardiography, tissue Doppler imaging (TDI) and two-dimensional speckle tracking imaging (STI). The weight, the rate of complications, and the rate of cesarean section were significantly higher in the IDMs group than in the control group. Significant positive correlation was present between the levels of HbA1c of IDMs and HbA1c of their mothers (P < 0.05). A significant deterioration of both systolic and diastolic functions measured by both conventional echocardiography and TDI was present in IDMs with both pre-gestational and gestational diabetes compared with the control group. Also, the septal/posterior wall ratio (SW/PW) was significantly higher in pregestational (1.86 ± 0.3) and gestational (2 ± 0.4) groups than in the control group (1 ± 0.06). Two-dimensional STI showed that the cardiac torsion was significantly impaired in pre-gestational (9.66 ± 2.5) and gestational (8.66 ± 3.9) groups when compared with the control group (5.4 ± 2.4) [P < 0.0001]. It also showed that the global strain was significantly impaired in pre-gestational (-10.4 ± 3.2) and gestational (-13.1 ± 4.7) groups when compared with the control group (-19 ± 2) [P < 0.0001]. However, no significant differences were present among the two patients' subgroups in echocardiographic data except for a significant decrease of E'/A' ratio and S wave at tricuspid annulus derived by TDI and impaired global strain derived by STI in infants of mothers with pre-gestational DM than those with gestational DM [P = 0.02]. SW/PW and cardiac torsion were significantly higher in infant of diabetic mother than the normal newborn and on the contrary systolic function and global strain were significantly lower in IDMs especially in infants of mother with pre-gestational diabetes. All the previous TDI findings did not show any significant correlation to neither maternal nor fetal HbA1c. Also, there was no significant correlation between cardiac torsion and the rest of TDI data neither in IDMs group nor in the control group. TDI and two-dimensional STI were efficient and sensitive tools able to early detect cardiac dysfunction in IDMs even in the absence of morphologic cardiac changes.

Maternal Hyperglycemia Directly and Rapidly Induces Cardiac Septal Overgrowth in Fetal Rats

Cardiac septal overgrowth complicates 10-40% of births from diabetic mothers, but perplexingly hyperglycemia markers during pregnancy are not reliably predictive. We thus tested whether fetal exposure to hyperglycemia is sufficient to induce fetal cardiac septal overgrowth even in the absence of systemic maternal diabetes. To isolate the effects of hyperglycemia, we infused glucose into the blood supply of the left but not right uterine horn in nondiabetic pregnant rats starting on gestational day 19. After 24 h infusion, right-sided fetuses and dams remained euglycemic while left-sided fetuses were moderately hyperglycemic. Echocardiograms in utero demonstrated a thickened cardiac septum among left-sided (glucose-exposed, 0.592 ± 0.016 mm) compared to right-sided (control, 0.482 ± 0.016 mm) fetuses. Myocardial proliferation was increased 1.5 ± 0.2-fold among left-sided compared to right-sided fetuses. Transcriptional markers of glucose-derived anabolism were not different between sides. However, left-sided fetuses exhibited higher serum insulin and greater JNK phosphorylation compared to controls. These results show that hyperglycemic exposure is sufficient to rapidly induce septal overgrowth even in the absence of the myriad other factors of maternal diabetes. This suggests that even transient spikes in glucose may incite cardiac overgrowth, perhaps explaining the poor clinical correlation of septal hypertrophy with chronic hyperglycemia.

Elevated neonatal insulin-like growth factor I is associated with fetal hypertrophic cardiomyopathy in diabetic women

OBJECTIVE

We sought to determine if fetal hypertrophic cardiomyopathy (HCM) or cardiac dysfunction is associated with elevated maternal or neonatal insulin-like growth factor (IGF)-I levels in women with diabetes.

STUDY DESIGN

In a prospective cohort study, fetal echocardiogram findings at 36 weeks' gestation in women with pregestational diabetes mellitus were compared to those in women without diabetes mellitus. HCM was defined as septal or free wall thickness ≥5 mm and cardiac dysfunction as a modified myocardial performance index ≥0.43. Cord serum IGF-I levels at delivery were measured with enzyme-linked immunosorbent assay. Neonates with abnormal fetal echocardiogram were followed up until resolution or 6 months of life.

RESULTS

In all, 75 participants completed fetal echocardiography (55 diabetics and 20 controls). In the diabetic group, 33 of 55 (60%) had abnormal fetal echocardiograms with cardiac dysfunction in 21 of 55 (38.2%) and HCM in 8 of 55 (14.5%) and both in 4 of 55 (7.3%). At 6 months of age, 1 of 12 (8%) had persistent HCM. None in the comparison group had abnormal findings. There were no significant clinical differences in those diabetic women with normal vs abnormal fetal echocardiograms. However, among diabetic women, mean neonatal IGF-I was significantly higher in fetuses with HCM (80 ± 16 ng/mL) as compared to those without HCM (61 ± 18 ng/mL), (P < .001).

CONCLUSION

Elevated neonatal IGF-I appears to be associated with fetal HCM in fetuses of diabetic women.

Cardiomyopathy in offspring of pregestational diabetic mouse pregnancy

PURPOSE

To investigate cardiomyopathy in offspring in a mouse model of pregestational type 1 diabetic pregnancy.

METHODS

Pregestational diabetes was induced with STZ administration in female C57BL6/J mice that were subsequently mated with healthy C57BL6/J males. Offspring were sacrificed at embryonic day 18.5 and 6-week adolescent and 12-week adult stages. The size and number of cardiomyocyte nuclei and also the extent of collagen deposition within the hearts of diabetic and control offspring were assessed following cardiac tissue staining with either haematoxylin and eosin or Picrosirius red and subsequently quantified using automated digital image analysis.

RESULTS

Offspring from diabetic mice at embryonic day 18.5 had a significantly higher number of cardiomyocyte nuclei present compared to controls. These nuclei were also significantly smaller than controls. Collagen deposition was shown to be significantly increased in the hearts of diabetic offspring at the same age. No significant differences were found between the groups at 6 and 12 weeks.

CONCLUSIONS

Our results from offspring of type 1 diabetic mice show increased myocardial collagen deposition in late gestation and have increased myocardial nuclear counts (hyperplasia) as opposed to increased myocardial nuclear size (hypertrophy) in late gestation. These changes normalize postpartum after removal from the maternal intrauterine environment.

Stillbirth in diabetic pregnancies

Pregnancy in women with pregestational diabetes is associated with high perinatal morbidity and mortality. Stillbirth accounts for the majority of cases with perinatal death. Intrauterine growth restriction, pre-eclampsia, foetal hypoxia and congenital malformations may be contributing factors, but more than 50% of stillbirths are unexplained. Majority of stillbirths are characterised by suboptimal glycaemic control during pregnancy. Foetal hypoxia and cardiac dysfunction secondary to poor glycaemic control are probably the most important pathogenic factors in stillbirths among pregnant diabetic women. There is thus a need for new strategies for improving glycaemic control to near-normal levels throughout pregnancy and for preventing and treating hypertensive disorders in pregnancy. Antenatal surveillance tests including ultrasound examinations of the foetal growth rate, kick counting and non-stress testing of foetal cardiac function are widely used. However, future research should establish better antenatal surveillance tests to identify the infants susceptible to stillbirth before it happens.

Increased fat mass and cardiac septal hypertrophy in newborn infants of mothers with well-controlled diabetes during pregnancy

BACKGROUND

Improved glycaemic control during pregnancy in mothers with type 1 diabetes (T1DM) and gestational diabetes (GDM) has resulted in a marked reduction of perinatal mortality and morbidity, but the prevalence of macrosomia is usually high.

OBJECTIVE

We used non-invasive anthropometric methods to estimate the body composition and the thickness of the interventricular heart septum in 18 infants of mothers with well-controlled T1DM, 10 infants of mothers with GDM and 28 infants of healthy control mothers matched for gestational age and mode of delivery.

METHODS

Skinfold measurements were obtained with a Harpenden calliper within 48 h after delivery. Echocardiography was also performed to measure the thickness of the interventricular septum. Cord blood was sampled for assays of C-peptide, leptin and IGF-I.

RESULTS

The rates of macrosomia (gestational age-adjusted birth weight >2 standard deviation score, SDS) were 56 and 30% in infants of mothers with T1DM and GDM, respectively, compared to 10% in control infants. The body fat content was 40% (0.2 kg) higher and the interventricular heart septum thickness was increased by 20% in both groups of infants of diabetic mothers. We found no associations between maternal levels of HbA1c during pregnancy and body composition or interventricular heart septum thickness. Cord levels of C-peptide and leptin were significantly higher in infants of T1DM mothers than in control infants. Cord leptin level was associated with birth weight SDS and percent body fat in infants of T1DM mothers. IGF-I was associated with percent body fat in infants of GDM mothers and control mothers. A multiple-regression analysis showed that 50% of the variation in body weight SDS could be determined, with IGF-I, leptin and C-peptide as independent variables.

CONCLUSION

Both fat mass and cardiac septal thickness are increased in newborn infants of women with T1DM and GDM in spite of efforts to achieve good glycaemic control during pregnancy.

Echocardiographic findings of congenital cardiopathies among fetuses of diabetic pregnant women and their relationship with plasma fructosamine levels

OBJECTIVE

To study the occurrence of congenital cardiopathies at echocardiography (CCE) in fetuses whose mothers had preexisting diabetes mellitus (PGDM) and to study the potential of using fructosamine level as a late marker (beyond the first trimester) for CCE.

METHODS

A register study covering 91 pregnant women that underwent routine fetal echocardiography ordered due to PGDM. The first dosage of plasma fructosamine found in 65 medical records was analyzed during prenatal care (20.4 ± 8.0 weeks of gestation). The presence or absence of structural or functional CCE was associated with fructosamine levels by logistic regression. We assessed the effect modification odds ratio by maternal age and insulin usage.

RESULTS

Thirty-four fetuses (52.3% of 65 fetuses) presented CCE. Twenty of them had functional CCE and 14 presented structural CCE. The mean maternal plasma fructosamine level was higher among pregnant women whose fetuses presented CCE than in those whose fetuses did not (2.86 ± 0.73 mmol/l, 2.22 ± 0.54 mmol/l, respectively, p < 0.0001). Crude OR for CCE and abnormal plasma fructosamine (>2.68 mmol/l) was 9.6 (2.8-33.7, 95% CI, p < 0.0001). Adjusted OR by maternal age and insulin usage was 10.9 (2.7-45.2, 95% CI p < 0.0001).

CONCLUSIONS

An abnormal plasma fructosamine level increases the chances of CCE occurring among referral pregnant women with PGDM.

Assessment of cardiomyopathy in fetuses of women with false positive oral glucose loading test

OBJECTIVE

To evaluate fetal asymmetric septal hypertrophy in women with a false positive oral glucose loading test (OGL).

STUDY DESIGN

OGL was applied to 79 pregnant women at gestational age between 24 and 28 weeks. The first study group consisted of patients with a normal OGL. Cases having glucose levels above 130 mg/dL after 50 g OGL but a normal 100g oral glucose tolerance test (OGTT) formed a second group. M-mode echocardiography was then performed. Fetal septal and left ventricular posterior wall (LVPW) thicknesses in Group 1 and Group 2 were compared.

RESULTS

Mean septal and LVPW thickness was slightly higher in the second group but there was no statistically significant difference between the two groups.

CONCLUSIONS

Although statistically not significant, there is some increase in septal and ventricular wall thickness in cases with high OGL but normal OGTT. The study also provides evidence of the absence of prominent septal and ventricular thickening in these cases with minimal glucose intolerance.

Fetal cardiac effects of maternal hyperglycemia during pregnancy

Maternal diabetes mellitus is associated with increased teratogenesis, which can occur in pregestational type 1 and type 2 diabetes. Cardiac defects and with neural tube defects are the most common malformations observed in fetuses of pregestational diabetic mothers. The exact mechanism by which diabetes exerts its teratogenic effects and induces embryonic malformations is unclear. Whereas the sequelae of maternal pregestational diabetes, such as modulating insulin levels, altered fat levels, and increased reactive oxygen species, may play a role in fetal damage during diabetic pregnancy, hyperglycemia is thought to be the primary teratogen, causing particularly adverse effects on cardiovascular development. Fetal cardiac defects are associated with raised maternal glycosylated hemoglobin levels and are up to five times more likely in infants of mothers with pregestational diabetes compared with those without diabetes. The resulting anomalies are varied and include transposition of the great arteries, mitral and pulmonary atresia, double outlet of the right ventricle, tetralogy of Fallot, and fetal cardiomyopathy.A wide variety of rodent models have been used to study diabetic teratogenesis. Both genetic and chemically induced models of type 1 and 2 diabetes have been used to examine the effects of hyperglycemia on fetal development. Factors such as genetic background as well as confounding variables such as obesity appear to influence the severity of fetal abnormalities in mice. In this review, we will summarize recent data on fetal cardiac effects from human pregestational diabetic mothers, as well as the most relevant findings in rodent models of diabetic cardiac teratogenesis.

Intrapartum fetal ECG and diabetes

AIM

The objective of this study was to determine the prevalence and types of ST-segment changes of the fetal electrocardiogram (FECG) during labour in term fetuses born to mothers with diabetes mellitus (DM) or gestational diabetes.

METHODS

This was a retrospective case-control study involving populations from two multi centre trials: the Swedish Randomized Control Trial and the European Union ST-analysis (EU-STAN) trial. ST-segment changes were assessed in 104/309 cases and 207/468 controls from the Swedish and EU-STAN trials, respectively.

RESULTS

ST depression was present on the FECG in 22.1% of fetuses of mothers with DM compared to 12% of controls OR = 2.6, 95% CI = 1.4-4.7, p = 0.002 after adjusting for trial, birth weight, and nulliparity. ST elevation was present in 47.1% of DM patients and 41.2% of controls (OR = 1.4, 95% CI = 0.9-2.3, p = 0.18).

CONCLUSION

ST depression on the FECG was significantly more prevalent in the fetuses of mothers with DM, probably not indicating hypoxia but an altered ability of the myocardium to respond to the stress of labour. Further studies into the mechanism of fetal compromise during diabetic labour, are required.

Effect of pregestational diabetes mellitus on fetal cardiac function and structure

OBJECTIVE

Fetuses of diabetic pregnancy experience cardiomyopathy, the intracardiac cause of which is understood poorly. The aim of this study was to assess the interrelation between cardiac functional and structural changes in fetuses of mothers with pregestational diabetes mellitus.

STUDY DESIGN

Twenty-six mothers with pregestational diabetes mellitus were recruited prospectively to have a fetal echocardiogram at 13, 20, and 36 weeks of gestation to assess cardiac function and structure. For comparison, 30 healthy control subjects were recruited at each gestational age.

RESULTS

In the first trimester, there was evidence of poorer fetal cardiac diastolic function among the diabetic cohort (lower left early/atrial ratio, longer isovolumetric relaxation time and higher left myocardial performance index; P < .05). In the third trimester, the fetal interventricular septum and the right ventricular free wall were thicker in the diabetic cohort (P < .05).

CONCLUSION

In fetuses of pregestational diabetic pregnancy, sonographic evidence of altered cardiac function is evident before ultrasound evidence of cardiac structural changes. This suggests that altered cardiac function may precede cardiac structural changes in fetuses of pregestational diabetic pregnancy.

Cardiomyopathy and cardiomegaly in stillborn infants of diabetic mothers

To report the incidence of cardiomegaly in stillborn normally formed infants of mothers with diabetes mellitus. This is a retrospective study with institutional ethics approval. The presence of cardiomegaly was recorded in stillborn infants of diabetic mothers (N = 27) and compared with that recorded in stillborn large-for-gestational age (LGA > 90th percentile, n = 18) and stillborn appropriately grown (10th to 90th percentiles, n = 107) nondiabetic infants. Blinded to the clinical details, the histology slides were reviewed to measure cardiac wall thickness and to record the presence or absence of myocardial fiber disarray. Stillborn infants of mothers with diabetes mellitus, when compared with appropriately grown stillborn nondiabetic infants and when adjusted for birth weight, had heavier hearts, thicker ventricular free wall measurements, and lighter brains. While cardiomegaly was reported in 22% of stillborn LGA infants, comparison with stillborn appropriately grown infants revealed no difference in heart weights corrected for birth weight. Comparison of LGA nondiabetic infants with stillborn diabetes mellitus infants revealed greater actual heart weight/expected for birth weight (P < 0.05) and lighter brains (actual brain weight/expected for birth weight, P < 0.05) in the diabetes mellitus group. Cardiomegaly is a common finding in stillborn infants of mothers with diabetes mellitus and may contribute to the risk of fetal death in these pregnancies.

Insulin-like growth factor-1 receptor expression in the placentae of diabetic and normal pregnancies

BACKGROUND

Septal hypertrophic cardiomyopathy (sHCM) is a characteristic anomaly of the infant of diabetic mother (IDM). Insulin-like growth factor-1 (IGF-1) has been identified as a mediator of tissue overgrowth and we have previously shown that maternal IGF-1 levels were significantly elevated among neonates with asymmetrical sHCM. IGF-1 does not cross the placenta; it exerts physiologic action through binding to the IGF-1 receptor (IGF-1R). Localisation and expression of IGF-1R in term diabetic pregnancies are largely unclear. We have studied IGF-1R in the placentae of diabetic and normal pregnancies and this receptor expression in association with neonates with sHCM.

METHODS

IGF-1R localization and expression in the placentae of six diabetic pregnancies associated with neonatal sHCM were compared with six each of randomly selected diabetic and normal pregnancies without neonatal sHCM by immunohistochemistry. The staining for IGF-1R in the deciduas, cytotrophoblasts, syncytiotrophoblasts and villous endothelium for these 18 samples were assessed and scored by two pathologists who were blinded to the respective diagnoses.

RESULTS

Placental IGF-1R staining was negative in the villous endothelium for all three groups. IGF-1R staining was present in deciduas, cytotrophoblasts and syncytiotrophoblasts but the staining was weaker in the entire group of infants with sHCM compared to those without sHCM.

CONCLUSIONS

IGF-1R is localized in all cell types of the placenta except in villous endothelium. Weaker placental IGF-1R staining in the placentae of diabetic pregnancies associated with sHCM suggests reduced expression of IGF-1R. This may be a down-regulatory response to elevated maternal IGF with neonatal sHCM outcome.

Increased periconceptual maternal glycated haemoglobin in diabetic mothers reduces fetal long axis cardiac function

OBJECTIVE

To compare ventricular long axis function in fetuses of diabetic mothers (FDM) with contemporaneously studied normal controls (N) and to assess the effect of pre-pregnancy diabetic control on these measurements.

DESIGN

Long axis function was compared in 41 FDM and 159 N fetuses in a cross sectional observational study.

SETTING

Fetal medicine unit.

METHODS AND RESULTS

Echocardiography confirmed structural normality. Pulsed wave valvar Doppler velocimetry, lengthening and shortening myocardial velocities, and amplitude of ventricular long axis movement were recorded at the base of the left and right ventricular free walls and septum. Periconceptual diabetic control was assessed by haemoglobin A1c (HbA1c) in early pregnancy. Doppler and myocardial velocities were negatively related and myocardial thickness was positively related with HbA1c. In both cohorts all variables except mitral and tricuspid late filling (A wave) velocities were dependent on gestational age. FDM gestational age related values were higher for most variables and robust analysis of covariance showed significantly different maturation patterns in mitral valve E:A ratio (p = 0.036) and pulmonary velocity (p = 0.04), late lengthening myocardial velocities (left p = 0.016 and right p = 0.066), left myocardial shortening velocities (p = 0.008), and left free wall (p = 0.03) and septal (p = 0.04) amplitude of motion. FDM septal thickness was significantly increased throughout gestation (p < 0.0001).

CONCLUSION

Periconceptual diabetic control influences fetal cardiac performance and myocardial hypertrophy but, unlike the pathophysiology of adult ventricular hypertrophy, is accompanied by functional adaptation. It is unlikely to explain the increased rate of late stillbirth observed in diabetic pregnancies.

Increased plasma pro-B-type natriuretic peptide in infants of women with type 1 diabetes

BACKGROUND

Up to 40% of newborn infants of women with type 1 diabetes have echocardiographic signs of cardiomyopathy. Increased plasma concentrations of B-type natriuretic peptide (BNP) and its precursor (proBNP) are markers of cardiac failure and hypoxia in adults. In this study, we investigated whether plasma concentrations of proBNP and/or BNP are increased in infants of women with type 1 diabetes.

METHODS

Plasma BNP and proBNP were measured with RIAs. The proBNP assay measures both intact proBNP and NH(2)-terminal fragments derived from this precursor, whereas the BNP assay measures only BNP-32 and not proBNP.

RESULTS

Infants of women with diabetes and hemoglobin A(1c) (Hb A(1c)) > or =6.2% before delivery had a higher median plasma proBNP concentration (31 pmol/L; interquartile range, 21-47 pmol/L; n = 16) than infants of healthy women [16 (9-32) pmol/L; n = 21; P = 0.01]. Infants of women with diabetes and Hb A(1c) <6.2% (n = 15) had intermediate values. The plasma BNP and proBNP concentrations were closely associated (r(2) = 0.80; P < 0.0001); within the group of infants of women with diabetes and Hb A(1c) > or =6.2%, both correlated with the degree of fetal stress during labor.

CONCLUSIONS

Maternal diabetes and suboptimal metabolic control may affect the fetal heart and predominantly stimulate proBNP secretion in conjunction with perinatal stress.

Behavior of septum primum mobility in third-trimester fetuses with myocardial hypertrophy

OBJECTIVES

The mobility of the septum primum (SP) in the fetus is a diastolic phenomenon and could be related to left atrial pressure. We studied the linear displacement of the SP in the left atrium in fetuses of diabetic mothers (FDM) with and without septal hypertrophy (SH) and in normal fetuses of normoglycemic mothers. In this study we set out to test the hypothesis that the linear displacement of the SP flap valve is less marked in fetuses with SH than in those without SH.

METHODS

The ratio between the linear displacement of the flap valve and the left atrial diameter (excursion index (EI)) was compared in ten FDM with SH, eight FDM with normal septal thickness and eight normal fetuses of non-diabetic mothers. Atrioventricular flow velocities were also compared in the three groups.

RESULTS

Comparison of the three groups showed that in FDM with SH, the mean EI was 0.36 +/- 0.09, in FDM without SH it was 0.51 +/- 0.09 (P = 0.001) and in the control fetuses it was 0.49 +/- 0.12 (P = 0.03). There was a significant negative correlation between septal thickness and EI in FDM with SH. There was no correlation between septal thickness and atrioventricular flow velocities.

CONCLUSION

Mobility of the SP in FDM with SH is reduced and there is an inverse correlation between the linear displacement of the SP and septal thickness. These findings may be related to changes in left ventricular diastolic function secondary to myocardial hypertrophy.

Maternal issues affecting the fetus

Maternal disorders and exposures that affect fetal cardiac structure and function are reviewed, emphasizing fetal echocardiographic diagnosis and monitoring, and approaches for in utero therapy. Maternal diabetes, hyperthyroidism, lupus erythematosis, epilepsy, congenital heart disease, infections, and drug exposures are considered.

Fetal cardiac function and septal thickness in diabetic pregnancy: a controlled observational and reproducibility study

OBJECTIVE

To determine the reproducibility of duplex Doppler waveform analysis and fetal cardiac interventricular septal thickness measurement and to compare these parameters in matched pregnancies with and without well-controlled maternal Type 1 diabetes at 18-20 weeks of gestation.

DESIGN

A prospective blind twin cohort study and a blinded inter-observer and intra-observer agreement study.

SETTING

A tertiary referral prenatal diagnostic unit within a university hospital.

RESULTS

Good inter- and intra-observer agreement was found for the measurement of transvalvular peak flow velocities and the duration of ventricular ejection in the fetal heart. Inter-observer agreement for aortic flow acceleration rate was poor. M-mode measurement of interventricular septal thickness showed moderate reproducibility. The mean (SD) width of the interventricular septum in the fetuses of well controlled diabetic women was 2 1 mm (0.2 mm), and was significantly greater (P=0.01) when compared with the corresponding value in matched controls [1.9 mm (0.2 mm)]. No cardiac functional differences were evident.

CONCLUSIONS

On-screen video analysis of Doppler cardiac flow waveforms and M-mode measurement of intraventricular septal thickness demonstrated good reproducibility. The fetuses of well controlled diabetic pregnancies demonstrated signs of altered cardiac morphology early in pregnancy, before any evident alterations in cardiac function.

Fetal cardiac hypertrophy and cardiac function in diabetic pregnancies

OBJECTIVE

Our purpose was to evaluate the relationship between fetal cardiac wall hypertrophy and ventricular function in fetuses of metabolically controlled, insulin-requiring diabetics.

STUDY DESIGN

M-mode directed fetal echocardiography included measurements of left and right ventricular free wall and interventricular septal thickness and ventricular diastolic and systolic dimensions. Fetal measurements included biparietal diameter, estimation of fetal weight, and cardiac area/thoracic area. Cardiac size is expressed as a ratio of wall thickness/biparietal diameter, and function is expressed as ventricular shortening fraction (Ventricular diastolic dimension-Ventricular systolic dimension/Ventricular diastolic dimension). Fetuses of diabetics at 20 to 24, 28 to 31, and 32 to 36 weeks' gestation were compared with normal fetuses of nondiabetic mothers at similar gestational ages, which were used as a control group.

RESULTS

Study and control groups were comparable in mean gestational age (22 vs 20, 29 vs 29, 35 vs 34 weeks) in each of groups 1, 2, and 3. All fetuses tested fell within these groups. Estimated fetal weight, cardiac area/thoracic area, right ventricular wall thickness/biparietal diameter, and interventricular septal thickness/biparietal diameter were greater in the study group between 32 and 36 weeks: 3227 +/- 430 versus 2235 +/- 176 gm (p < 0.05), 0.32 versus 0.29, (p < 0.05), 0.53 +/- 0.05 versus 0.44 +/- 0.05 mm (p < 0.05), and 0.50 +/- 0.3 versus 0.46 +/- 0.5 mm (p < 0.05), respectively. Right ventricular shortening fraction/left ventricular shortening fraction was significantly different from controls in this group (1.30 vs 0.89, p < 0.05). This change was a function of altered right ventricular shortening fraction in late diabetic pregnancy. Right ventricular shortening fraction in the study groups was 0.39, 0.36, and 0.52, respectively, versus 0.36, 0.41, and 0.33 in controls. Left ventricular shortening fraction in the group at 32 to 36 weeks and in controls in three groups was 0.42, 0.39, 0.40 and 0.44, 0.37.

CONCLUSION

These findings reveal an increase in right ventricular shortening fraction associated with global cardiac enlargement. Myocardial hypertrophy involving right ventricular wall thickness and interventricular septal thickness in metabolically stable insulin-requiring diabetics revealed hypercontractility of the right ventricle.

Analysis of factors influencing ventricular filling patterns in fetuses of type I diabetic mothers

In an effort to determine the factors influencing the abnormal ventricular filling patterns of fetuses of type I diabetic mothers, Doppler flow velocity waveforms were recorded from fetal atrioventricular valves in 37 pregnancies complicated by type I diabetes immediately before an elective cesarean section. The ratio between the peak velocities during early passive ventricular filling and active atrial filling was calculated at the level of both atrioventricular valves and related to different factors including ventricular chamber wall thickness, heart rate, umbilical vein hematocrit and time to peak velocities values obtained at the outflow tract. Multiple stepwise regression demonstrated that the interventricular wall thickness, heart rate and hematocrit values significantly and independently affected the ratios between early and active ventricular filling from mitral and tricuspid valves. As a consequence all these factors should be taken into account in the interpretation of atrioventricular Doppler indices.

Role of prenatal echocardiography in the study of hypertrophic cardiomyopathy in the fetus

The increased incidence of hypertrophic cardiomyopathy in children of diabetic mothers has already been demonstrated, but its prenatal diagnosis has not yet been extensively studied. The purpose of this prospective study was to evaluate the frequency, severity, and echocardiographic features of fetal hypertrophic cardiomyopathy in a population with several indications for prenatal echocardiography. From March 1987 to April 1991, 283 fetuses were submitted to comprehensive prenatal echocardiography, including M-mode measurements, cross-sectional imaging, Doppler studies, and color flow mapping. One hundred seventy-six were pregnancies complicated by previous or gestational diabetes. The diagnosis of disproportionate septal hypertrophy was made in 39 fetuses (mean septal thickness 7.12 +/- 1.6 mm), at a mean gestational age of 32 weeks. Diabetes mellitus was present in 36 of these pregnancies (92.3%). In four cases, nonimmune hydrops was detected. A systolic anterior motion of the mitral valve was present in three fetuses, but only one showed a gradient across the left ventricular outflow tract. Postnatal echocardiographic examination in 27 babies did not show false positivity. In ten cases, spontaneous regression of the septal hypertrophy was shown. There were three neonatal deaths, unrelated to the myocardial disease. We concluded that transient hypertrophic cardiomyopathy is a frequent entity, especially when associated with diabetes during gestation, being a potential cause for nonimmune hydrops. Fetal echocardiography is the method of choice for its prenatal diagnosis and should always be indicated in diabetic mothers.

Cardiac function in fetuses of type I diabetic mothers

Cardiac function was cross-sectionally studied by means of M-mode and Doppler echocardiography in 40 fetuses of mothers with well-controlled insulin-dependent diabetes at 20 to 38 weeks of gestation. These variables were measured: interventricular septal thickness, ratio between the peak velocities during early passive ventricular filling and active atrial filling at the level of the atrioventricular valves, peak velocities, and the time to peak velocity at the level of the ascending aorta and the pulmonary artery. The values obtained were compared with our reference limits for gestation. A significant increase of interventricular septal thickness that was unrelated to maternal glycosylated hemoglobin levels was evidenced. Early passive ventricular filling/active atrial filling ratios were significantly lower in fetuses of diabetic mothers than in control fetuses. These differences were significantly related to interventricular septal thickness. No significant modifications were found in either aortic or pulmonary peak velocities or in time to peak velocity values. These findings suggest that in spite of an adequate metabolic control an interventricular septal hypertrophy that affects cardiac diastolic function develops in fetuses of diabetic mothers.