Prediction of Fetal Hypertrophic Cardiomyopathy in Diabetic Pregnancies Compared with Postnatal Outcome

Retrofitting the Heart: Explaining the Enigmatic Septal Thickening in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy is the most common genetic cardiac disease and is characterized by left ventricular hypertrophy. Although this hypertrophy often associates with sarcomeric gene mutations, nongenetic factors also contribute to the disease, leading to diastolic dysfunction. Notably, this dysfunction manifests before hypertrophy and is linked to hypercontractility, as well as nonuniform contraction and relaxation (myofibril asynchrony) of the myocardium. Although the distribution of hypertrophy in hypertrophic cardiomyopathy can vary both between and within individuals, in most cases, it is primarily confined to the interventricular septum. The reasons for septal thickening remain largely unknown. In this article, we propose that alterations in muscle fiber geometry, present from birth, dictate the septal shape. When combined with hypercontractility and exacerbated by left ventricular outflow tract obstruction, these factors predispose the septum to an isometric type of contraction during systole, consequently constraining its mobility. This contraction, or more accurately, this focal increase in biomechanical stress, prompts the septum to adapt and undergo remodeling. Drawing a parallel, this is reminiscent of how earthquake-resistant buildings are retrofitted with vibration dampers to absorb the majority of the shock motion and load. Similarly, the heart adapts by synthesizing viscoelastic elements such as microtubules, titin, desmin, collagen, and intercalated disc components. This pronounced remodeling in the cytoskeletal structure leads to noticeable septal hypertrophy. This structural adaptation acts as a protective measure against damage by attenuating myofibril shortening while reducing cavity tension according to Laplace Law. By examining these events, we provide a coherent explanation for the septum's predisposition toward hypertrophy.

Incidence of Fetal Myocardial Hypertrophy in Mother with Diabetes Mellitus by Using Cardio-Spatiotemporal Image Correlation (STIC) M-Mode

Objective

The aim was to demonstrate the prevalence of fetal myocardial hypertrophy (FMH) in diabetes mellitus (DM) pregnant women using spatio-temporal image correlation (STIC) M-mode.

Material and Methods

This prospective descriptive study was conducted at Bhumibol Adulyadej Hospital (BAH) Royal Thai Air Force between April and December 2022. Participants were singleton DM pregnant women with gestational age (GA) between 18 and 40 weeks who had antenatal care and delivery at BAH. DM screening was randomized blood sugar obtained from all participants. All participants underwent fetal heart exams by four-dimension ultrasound with STIC M-mode.

Results

One hundred and forty-five participants were recruited and classified as pregestational (PDM) and gestational DM (GDM) at 31 and 114 cases, respectively. The mean age of participants was 31.7 years old. Fasting blood sugar (FBS) of PDM was significantly higher than GDM (105.1 vs 87.0 mg%). GDMA2 had more elevated FBS than GDMA1 (p < 0.001). PDM had significantly greater FBS and two-hour postprandial blood sugar (2hr-PP) than GDM (105.1/87.0 and 151.5/117.9 mg%, respectively). FBS and 2hr-PP of GDMA2 were more than GDMA1 with statistical significance. Good glycemic control of GDM was significantly better than PDM. GDMA1 had better glycemic control than GDMA2 with statistical significance. Four-fifth (115/145) of participants had FMH. FMH and estimated fetal weight among PDM and GDM were comparable. Both good and poor glycemic control had similar FMH. Neonatal outcomes of FMH or non-FMH infants were similar.

Conclusion

The prevalence of FMH in diabetic pregnant women was 79.3%. Glycemic control had no correlation to FMH.

Maternal and neonatal outcomes in mothers with diabetes mellitus in qatari population

Abstract

Background

Diabetes Mellitus (DM) is a major cause of maternal, fetal, and neonatal morbidities. Our objective was to estimate the effect of both pre-pregnancy and gestational DM on the growth parameters of newborns in the Qatari population.

Methods

In this population-based cohort study, we compared the data of neonates born to Qatari women with both pre-pregnancy and gestational diabetes mellitus in 2017 with neonates of healthy non-diabetic Qatari women.

Results

Out of a total of 17020 live births in 2017, 5195 newborns were born to Qatari women. Of these, 1260 were born to women with GDM, 152 were born to women with pre-pregnancy DM and 3783 neonates were born to healthy non-diabetic (control) women. The prevalence of GDM in the Qatari population in 2017 was 24.25%. HbA1C% before delivery was significantly higher in women with pre-pregnancy DM (mean 6.19 ± 1.15) compared to those with GDM (mean 5.28 ± 0.43) (P <0.0001). The mean birth weight in grams was 3066.01 ± 603.42 in the control group compared to 3156.73 ± 577.88 in infants born to women with GDM and 3048.78 ± 677.98 in infants born to women with pre-pregnancy DM (P <0.0001). There was no statistically significant difference regarding the mean length (P= 0.080), head circumference (P= 0.514), and rate of major congenital malformations (P= 0.211). Macrosomia (Birth weight > 4000 gm) was observed in 2.7% of the control group compared to 4.8% in infants born to women with GDM, and 4.6% in infants born to women with pre-pregnancy DM (P= 0.001). Multivariate logistic regression analysis demonstrated that higher maternal age (adjusted OR 2.21, 95% CI 1.93, 2.52, P<0.0001), obesity before pregnancy (adjusted OR 1.71, 95% CI 1.30, 2.23, P<0.0001), type of delivery C-section (adjusted OR 1.25, 95% CI 1.09, 1.44, P=0.002), and body weight to gestational age LGA (adjusted OR 2.30, 95% CI 1.64, 2.34, P<0.0001) were significantly associated with increased risk of GDM.

Conclusion

Despite the multi-disciplinary antenatal diabetic care management, there is still an increased birth weight and an increased prevalence of macrosomia among the infants of diabetic mothers. More efforts should be addressed to improve the known modifiable factors such as women's adherence to the diabetic control program. Furthermore, pre-pregnancy BMI was found to be significantly associated with gestational DM, and this is a factor that can be addressed during pre-conceptional counseling.

Elevated fetal middle cerebral artery peak systolic velocity in diabetes type 1 patient: a case report

Objectives

Doppler measurement of fetal middle cerebral artery peak systolic velocity (MCA-PSV) is used to screen fetuses at risk of developing fetal anemia. This screening tool has demonstrated to be accurate to estimate the likelihood of fetal anemia and it has been used in the management of fetuses at this risk. It is rare to find in the literature cases of increased MCA-PSV in the absence of fetal anemia. We present the case of an elevated MCA-PSV in the absence of common causes of fetal anemia.

Case presentation

A 30-year-old woman at 21 weeks of gestation was referred to our unit with a left fetal renal agenesis and single umbilical artery diagnosis. The patient had a poorly controlled type 1 Diabetes with a booking HbA1C of 9.1%. At 31 weeks of gestation, MCA-PSV was raised (>1.5 multiples of the median) in the absence of any cause of fetal anemia and discrepancy of ventricular size with normal fetal heart function were seen. In a subsequent scan, thick interventricular septum was seen and hypertrophic cardiomyopathy (HC) was suggested. Follow-up ultrasonography showed a persistent MCA-PSV in a large for gestation age (LGA) fetus with HC. Due to the prenatal diagnosis of persistent elevated MCA-PSV in LGA fetus with diagnoses of HC in a poorly controlled type 1 diabetic patient labor was induced after fetal lung maturation. Biventricular hypertrophic cardiomyopathy was detected after birth.

Conclusions

HC may be an explanation for increased MCA-PSV without fetal anemia.

Use of vasopressin in neonatal hypertrophic obstructive cardiomyopathy: case series

OBJECTIVE

To determine the effect of vasopressin on arterial blood pressure in infants with neonatal hypertrophic obstructive cardiomyopathy (HOCM).

STUDY DESIGN

Retrospective case study in Neonatal ICU involving six infants; five born to mothers with diabetes mellitus (mean gestational age 37.5 ± 0.9 weeks). Vasopressin infusion was started at a mean dose of 0.3 ± 0.2 mU/kg/min.

RESULT

Initiation of vasopressin was followed by improved mean (p = 0.004), systolic (p = 0.028), and diastolic (p = 0.009) arterial pressure within 2 h. Heart rate (p = 0.025) and oxygen requirement (p = 0.021) also declined after initiation. Serum sodium declined initially and recovered by 72 h (p = 0.017).

CONCLUSION

Although there is limited experience with vasopressin use in neonatal HOCM, our case series suggests it may be beneficial for improving systemic hypotension and stabilization of hemodynamics. The potential for hyponatremia is high, necessitating careful fluid/electrolyte management. A prospective randomized trial is necessary to confirm safety and efficacy of vasopressin treatment in neonatal HOCM.

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

There is sparse Indian data on whether fetal echocardiography among pregnant diabetics would be useful to predict adverse perinatal/neonatal outcome.

Objectives

To study fetal cardiac changes in diabetic mothers and non-diabetic controls from 24 weeks gestation until the neonatal period; correlate them with maternal glycemic control; study their implications on adverse perinatal/neonatal outcome.

Methodology

Prospective observational cohort study. Pregnant diabetics (17 overt, 66 gestational) recruited beyond 24 weeks, divided as well (39) and poorly (44) controlled, based on American Diabetes Association 2016 criteria. Controls were 102 healthy non-diabetic pregnancies. Fetal echocardiography performed at weeks 24–32, 32–36, >37, and between 4 and 7 days on neonates. The thickness of Interventricular septum (IVS), Right Ventricle (RV), and Left ventricle (LV) assessed with M mode. E/A ratio across Tricuspid/Mitral valves and Tei index determined. TDI(Tissue Doppler imaging) used to assess tissue annular velocities across IVS, RV, and LV. Maternal glycemic control and various perinatal/neonatal adverse outcomes were recorded.

Results

Significant myocardial hypertrophy seen among fetuses of diabetic mothers versus controls, most severe at term among the poorly controlled diabetics. Structural changes persisted in the neonate. At term, fetal myocardial dysfunction was evident among diabetic pregnancies only as poor annular systolic velocity across IVS, RV using TDI. However, Tissue Doppler changes could not predict adverse perinatal/neonatal outcome. Myocardial dysfunction could not be demonstrated in the neonates. Myocardial hypertrophy at term was a surrogate marker for suboptimal glycemic control, and it could predict important neonatal morbidities like hypoglycaemia, hyperbilirubinemia, prolonged NICU stays, and persistent foetal cardiac shunts.

Conclusion

Our study shows a significant association between fetal myocardial hypertrophy and maternal glycemic control among GDM pregnancies. There also seems to be an association between fetal myocardial hypertrophy and some of the adverse perinatal events including hypoglycemia. However these newborns were not found to have clinically relevant cardiac comorbidities even though there was significant septal hypertrophy in utero.

Antenatal corticosteroids after 34 weeks' gestation: Do we have the evidence?

There is evidence to support the use of antenatal corticosteroids prior to late preterm birth at 35⁺⁰ to 36⁺⁶ weeks' gestation and for specific 'at-risk' populations, such as planned cesarean section birth and infants of women with diabetes in pregnancy, to reduce short-term neonatal respiratory morbidity. However, the overall size of effect at late preterm and term gestational ages is less than for early and moderate preterm birth and should be countered against the potential harms. Evidence from randomized trials suggest an increase in the incidence of neonatal hypoglycemia after corticosteroid use prior to late preterm birth; any effect of antenatal corticosteroids on neonatal glycemic control after planned cesarean section birth or for infants born to mothers with diabetes in pregnancy is unknown. Accumulating evidence suggests neonatal hypoglycemia may adversely affect childhood development. To date, no trials of antenatal corticosteroids after 34 weeks' gestation have reliably assessed outcomes beyond the neonatal period.

Fetal Cardiodynamics by Echocardiography in Insulin Dependent Maternal Diabetes and Its Correlation with Pregnancy Outcome

INTRODUCTION

Maternal diabetes mellitus is associated with an increased risk of fetal and neonatal morbidity and mortality. Usual screening tests have not proved to be good prognostic indicators of fetal distress. Fetal cardiodynamics is potentially a useful screening tool.

AIM

To determine if cardiodynamics of the fetus differ in pregnancy with diabetes requiring insulin than those without and to determine whether cardiodynamics predict fetal and neonatal outcomes.

MATERIALS AND METHODS

This prospective case control study was carried out in 40 pregnant women with diabetes who required insulin for blood sugar control. Twenty uncomplicated pregnant women were taken as controls. Systolic and diastolic cardiac functions along with interventricular septal thickness were assessed at 26-28 weeks and again at 34-36 weeks of gestation in fetuses by echocardiography. Fetal and neonatal adverse outcomes were evaluated in terms of major and minor morbidity.

RESULTS

Among all parameters, E/A ratio across both mitral and tricuspid valves, myocardial performance index and cardiac output were significantly different in fetuses of diabetic mothers at both gestations. However, pulmonary vein pulsatility index and interventricular septal thickness were similar between the two groups. At 26-28 weeks of gestation myocardial performance index correlated with abnormal biophysical profile whereas cardiac output correlated with minor morbidity. At 34-36 weeks of gestation, cardiac output correlated with abnormal biophysical profile while both MPI and cardiac output correlated with minor morbidity.

CONCLUSION

Echocardiographic parameters of fetuses of diabetic women significantly differed from those of uncomplicated non-diabetic women. However, only myocardial performance index and cardiac output correlated with adverse fetal and neonatal outcomes.