271 - Factors Predicting Development of Septal Hypertrophy in Infants of Diabetic Mothers

Publication Number: 4267.271

Patrick Zacharias, Children's Hospital Los Angeles/Los Angeles General Hospital, Los Angeles, CA, United States; Eliezer Lasry, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States; Alex M. Dombrower, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States; Smeeta Sardesai, University of Southern California, Los Angeles, CA, United States; Hemananda Muniraman, Los Angeles General Medical Center, Los Angeles, CA, United States

Background: Infants of diabetic mothers (IDMs) are at risk for structural and functional cardiac abnormalities, most notably interventricular septal hypertrophy. While poor maternal glycemic control and elevated HbA1c levels are associated with septal hypertrophy, limited data exist on other maternal and neonatal factors associated with septal hypertrophy in IDMs.

Objective: To evaluate maternal and neonatal factors associated with septal hypertrophy among IDMs (including type 1, type 2, gestational diabetes, and abnormal oral glucose tolerance test). Secondary objectives included comparing echocardiographic parameters and NICU admission rates between IDMs with and without septal hypertrophy.

Design/Methods: This was a single-center retrospective study of IDMs born between January 2020 and the present. Baseline maternal and neonatal characteristics and echocardiographic ventricular dimensions were extracted from electronic medical records and echocardiogram reports. Comparisons between infants with and without septal hypertrophy were performed using bivariate and multinomial logistic regression analyses.

Results: A total of 122 IDMs were included, of whom 40 (33%) had septal hypertrophy. The septal hypertrophy group had a higher mean birth weight (3720 g vs. 2895 g, p < 0.01) and a greater proportion of large-for-gestational-age (LGA) infants (32.8% vs. 18.3%, p < 0.01). There were no differences in gestational age, maternal diabetes type, or HbA1c levels; however, maternal BMI was higher in the septal hypertrophy group (39 vs. 31, p < 0.01). On multinomial regression analysis, maternal BMI >35 (OR: 3.97, ​​CI 1.53-10.1, p < 0.01) and LGA status (OR: 3.65, 95% CI 1.31-10.13, p = 0.01) were independently associated with increased odds of septal hypertrophy (Tables 1 and Figure 1). In addition to increased septal thickness, infants with septal hypertrophy had higher LV end-diastolic diameter z-scores, posterior wall thickness (in diastole and systole), posterior wall-to-internal diameter ratio z-scores, fractional shortening, ejection fraction and LV mass (11 vs 7g, p< 0.01). All ECHO parameters evaluated can be found in Table 2. Neonatal intensive care unit admission rates were also higher in the septal hypertrophy group (85% vs. 67%, p < 0.02).

Conclusion(s): Higher maternal BMI and LGA status, but not maternal HbA1c, were associated with septal hypertrophy in IDMs in our single center study. Data collection is ongoing to validate and expand these preliminary findings with a larger cohort of infants.

Table 1: Comparison of Infant Characteristics Between IDM With and Without Septal Hypertrophy
Key: GA (gestation age), LGA (large for gestational age), T1DM (type 1 diabetes mellitus), T2DM (type 2 diabetes mellitus), GDM (gestational diabetes mellitus), OGTT (oral glucose tolerance test)

Figure 1: Predictors of Septal Hypertrophy in Infants of Diabetic Mothers


Table 2: ECHO Parameters Between IDM With and Without Septal Hypertrophy
Key: RV EDD (right ventricle end diastolic diameter), LV ESV (left ventricular end systolic volume), IVSd (interventricular septal thickness in diastole), IVSs (interventricular septal thickness in systole), LV EDD (left ventricle end diastolic diameter), LV PWd (left ventricle posterior wall thickness in diastole), LV PWs (left ventricle posterior wall thickness in systole), ID (internal diameter), LV EDV (left ventricular end diastolic volume)