To evaluate the influence of pre-existing maternal diabetes mellitus on fetal myocardial performance index and systolic-to-diastolic duration ratio.

Prospective cohort study included 179 pregnant women between 20 and 36w6d, divided into 3 groups: Group 1 (120, normal), Group 2 (31, type 1 diabetes mellitus), and Group 3 (28, type 2 diabetes mellitus). Systolic-to-diastolic duration ratio was calculated as the sum of isovolumic contraction time and ejection time divided by the sum of isovolumic relaxation time and ventricular filling time. Spectral Doppler was used to assess left ventricle systolic-to-diastolic duration ratio. Tissue Doppler was used to assess right ventricular filling time. Using spectral Doppler, left ventricle myocardial performance index was calculated as the sum of isovolumic contraction time and isovolumic relaxation time divided by ejection time.

Pre-existing maternal diabetes mellitus had a significant influence on fasting glucose levels (p < 0.001), left ventricle isovolumic contraction time (p < 0.001), left ventricle ejection time (p = 0.025), and left ventricle myocardial performance index (p < 0.001). Group 2 had higher left ventricle isovolumic contraction time (0.036 vs. 0.031 sec, p = 0.001) and left ventricle myocardial performance index (0.487 vs. 0.453, p = 0.003) compared with Group 1. Group 3 showed higher left ventricle myocardial performance index (0.492 vs. 0.449, p = 0.006) and lower left ventricle ejection time (0.161 vs. 0.169 sec, p = 0.038) than Group 1. Left ventricle systolic-to-diastolic duration (p = 0.704), right ventricle systolic-to-diastolic duration ratio’ (p = 0.757), left ventricle isovolumic contraction time (p = 0.163), left ventricle ejection time (p = 0.093), and left ventricle myocardial performance index (p = 0.087) were not useful parameters in predicting composite neonatal outcomes.

Pre-existing maternal diabetes mellitus had significant influence on fetal left ventricle myocardial performance index, but no effect on systolic-to-diastolic duration ratio. Systolic-to-diastolic duration ratio was not useful in predicting adverse perinatal outcomes.