The aim of the study: We assessed by echocardiography the left ventricular systolic and diastolic function in newborn infants of mothers with well-controlled pregestational type 1 or gestational diabetes (IDM) in comparison to normal term neonates.
Subjects and methods: Two-dimensional/M-mode and Doppler transmitral flow velocity measurements were performed in 18 IDM and 26 control infants of non-diabetic mothers (gestational ages 36-40 and 36-41 weeks, respectively) between days 2 and 5 after birth. In the IDM, there were nine mothers with pregestational (White class C or D) and nine mothers with gestational diabetes (White class A or A/B). Peak early and atrial filling velocity, early deceleration time, early acceleration time, early, atrial and total time velocity integrals were used to examine the left ventricular diastolic performance. We also calculated the early/atrial velocity ratio, early/atrial integral ratio and early/total integral ratio. The fractional shortening, fractional shortening area, midwall fractional shortening (mFS), left ventricular mass and indexed left ventricular mass for body surface area (BSA) and birth weight were used in assessment of left ventricular systolic performance.
Results: The early deceleration time was longer, resulting in higher early integral and early filling fraction (EFF) in the IDM than in the control infants (p<0.01). In the IDM, the fractional shortening was somewhat greater and the left ventricular mass/body surface area ratio was higher than in the control group (p<0.05), although the measures of systolic performance were within the normal range. There were no significant differences in the systolic or diastolic function parameters between the gestational and pregestational groups.
Conclusion: In the infants of mothers with well-controlled pregestational or gestational diabetes, we found prolonged deceleration time of early left ventricular diastolic filling, probably reflecting an impaired left ventricular relaxation rather than compliance. The mechanism for the findings may be maternal hyperglycemia during the third trimester and subsequent fetal hyperinsulinaemia leading to neonatal cardiac hypertrophy.