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.